Commit Graph

381 Commits

Author SHA1 Message Date
Rafael J. Wysocki 333eed7d20 PM: QoS: Simplify definitions of CPU latency QoS trace events
Modify the definitions of the CPU latency QoS trace events to take
one argument (since PM_QOS_CPU_DMA_LATENCY is always passed as the
pm_qos_class argument to them) and update the documentation of them
accordingly (while at it, make it explicitly mention CPU latency QoS
and relocate it after the device PM QoS trace events documentation).

The names and output format of the trace events do not change to
preserve user space compatibility.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-13 11:26:39 +01:00
Rafael J. Wysocki 5a7ea52b6f PM: QoS: Drop pm_qos_update_request_timeout()
The pm_qos_update_request_timeout() function is not called from
anywhere, so drop it along with the work member in struct
pm_qos_request needed by it.

Also drop the useless pm_qos_update_request_timeout trace event
that is only triggered by that function (so it never triggers at
all) and update the trace events documentation accordingly.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-13 11:25:40 +01:00
Linus Torvalds 41dcd67e88 A handful of small documentation fixes that wandered in.
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Merge tag 'docs-5.6-2' of git://git.lwn.net/linux

Pull Documentation fixes from Jonathan Corbet:
 "A handful of small documentation fixes that wandered in"

* tag 'docs-5.6-2' of git://git.lwn.net/linux:
  Allow git builds of Sphinx
  Documentation: changes.rst: update several outdated project URLs
  Documentation: build warnings related to missing blank lines after explicit markups has been fixed
  mailmap: add entry for Tiezhu Yang
  Documentation/ko_KR/howto: Update a broken link
  Documentation/ko_KR/howto: Update broken web addresses
  docs/locking: Fix outdated section names
2020-02-07 13:03:10 -08:00
Linus Torvalds e310396bb8 Tracing updates:
- Added new "bootconfig".
    Looks for a file appended to initrd to add boot config options.
    This has been discussed thoroughly at Linux Plumbers.
    Very useful for adding kprobes at bootup.
    Only enabled if "bootconfig" is on the real kernel command line.
 
  - Created dynamic event creation.
    Merges common code between creating synthetic events and
      kprobe events.
 
  - Rename perf "ring_buffer" structure to "perf_buffer"
 
  - Rename ftrace "ring_buffer" structure to "trace_buffer"
    Had to rename existing "trace_buffer" to "array_buffer"
 
  - Allow trace_printk() to work withing (some) tracing code.
 
  - Sort of tracing configs to be a little better organized
 
  - Fixed bug where ftrace_graph hash was not being protected properly
 
  - Various other small fixes and clean ups
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Merge tag 'trace-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:

 - Added new "bootconfig".

   This looks for a file appended to initrd to add boot config options,
   and has been discussed thoroughly at Linux Plumbers.

   Very useful for adding kprobes at bootup.

   Only enabled if "bootconfig" is on the real kernel command line.

 - Created dynamic event creation.

   Merges common code between creating synthetic events and kprobe
   events.

 - Rename perf "ring_buffer" structure to "perf_buffer"

 - Rename ftrace "ring_buffer" structure to "trace_buffer"

   Had to rename existing "trace_buffer" to "array_buffer"

 - Allow trace_printk() to work withing (some) tracing code.

 - Sort of tracing configs to be a little better organized

 - Fixed bug where ftrace_graph hash was not being protected properly

 - Various other small fixes and clean ups

* tag 'trace-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (88 commits)
  bootconfig: Show the number of nodes on boot message
  tools/bootconfig: Show the number of bootconfig nodes
  bootconfig: Add more parse error messages
  bootconfig: Use bootconfig instead of boot config
  ftrace: Protect ftrace_graph_hash with ftrace_sync
  ftrace: Add comment to why rcu_dereference_sched() is open coded
  tracing: Annotate ftrace_graph_notrace_hash pointer with __rcu
  tracing: Annotate ftrace_graph_hash pointer with __rcu
  bootconfig: Only load bootconfig if "bootconfig" is on the kernel cmdline
  tracing: Use seq_buf for building dynevent_cmd string
  tracing: Remove useless code in dynevent_arg_pair_add()
  tracing: Remove check_arg() callbacks from dynevent args
  tracing: Consolidate some synth_event_trace code
  tracing: Fix now invalid var_ref_vals assumption in trace action
  tracing: Change trace_boot to use synth_event interface
  tracing: Move tracing selftests to bottom of menu
  tracing: Move mmio tracer config up with the other tracers
  tracing: Move tracing test module configs together
  tracing: Move all function tracing configs together
  tracing: Documentation for in-kernel synthetic event API
  ...
2020-02-06 07:12:11 +00:00
Sameer Rahmani ff1e81a7e2 Documentation: build warnings related to missing blank lines after explicit markups has been fixed
Fix for several documentation build warnings related to missing blank lines
after explicit mark up.

Exact warning message:
 WARNING: Explicit markup ends without a blank line; unexpected unindent.

Signed-off-by: Sameer Rahmani <lxsameer@gnu.org>
Link: https://lore.kernel.org/r/20200203201543.24834-1-lxsameer@gnu.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-05 10:30:03 -07:00
Tom Zanussi 34ed63573b tracing: Documentation for in-kernel synthetic event API
Add Documentation for creating and generating synthetic events from
modules.

Link: http://lkml.kernel.org/r/734bf8789ff8700000c9acde61a553427910ddb5.1580323897.git.zanussi@kernel.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-30 09:46:29 -05:00
Mauro Carvalho Chehab d0ce47cb99 docs: tracing: Fix a broken label
Sphinx warnings about his:

	Documentation/trace/kprobetrace.rst:68: WARNING: undefined label: user_mem_access (if the link has no caption the label must precede a section header)

The problem is quite simple: Sphinx wants a blank line after
references.

Link: http://lkml.kernel.org/r/a83ea390bc28784518fce772b4c961ea1c976f14.1560883872.git.mchehab+samsung@kernel.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-28 23:14:13 -05:00
Masami Hiramatsu b8381ce7aa Documentation: tracing: Fix typos in boot-time tracing documentation
Fix typos in boottime-trace.rst according to Randy's suggestions.

Link: http://lkml.kernel.org/r/157949060335.25888.13153184562531693684.stgit@devnote2

Suggested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-21 18:25:16 -05:00
Masami Hiramatsu 4778194794 Documentation: tracing: Add boot-time tracing document
Add a documentation about boot-time tracing options in
boot config.

Link: http://lkml.kernel.org/r/157867246028.17873.8047384554383977870.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13 13:19:42 -05:00
Frank A. Cancio Bello 1209f45f7d docs: ftrace: Fix small notation mistake
The use of iff ("if and only if") notation is not accurate in this case.

Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Frank A. Cancio Bello <frank@generalsoftwareinc.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Link: https://lore.kernel.org/r/22f9a98a972c3155c7b478247a087a5efafde774.1577231751.git.frank@generalsoftwareinc.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-01-10 10:52:47 -07:00
Frank A. Cancio Bello 5b8914a67e docs: ftrace: Fix typos
Fix minor typos in the doc.

Suggested-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Frank A. Cancio Bello <frank@generalsoftwareinc.com>
Link: https://lore.kernel.org/r/9ef705d0208a4ca0852fed69bc0838a589a4df85.1577231751.git.frank@generalsoftwareinc.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-01-10 10:52:28 -07:00
Frank A. Cancio Bello a65d634e63 docs: ftrace: Clarify the RAM impact of buffer_size_kb
The current text could mislead the user into believing that the number
of pages allocated by each CPU ring buffer is calculated by the round
up of the division: buffer_size_kb / PAGE_SIZE.

Clarifies that a few extra pages may be allocated to accommodate buffer
management meta-data.

Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Suggested-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Frank A. Cancio Bello <frank@generalsoftwareinc.com>
Link: https://lore.kernel.org/r/6f33be5f3d60e5ffc061d8d2b329d3d3ccf22a8c.1577231751.git.frank@generalsoftwareinc.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-01-10 10:51:34 -07:00
Frank A. Cancio Bello d693b2883c docs: ftrace: Specifies when buffers get clear
Clarify a few places where the ring buffer and the "snapshot" buffer
are cleared as a side effect of an operation.

This will avoid users lost of tracing data because of these so far
undocumented behavior.

Signed-off-by: Frank A. Cancio Bello <frank@generalsoftwareinc.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20191218191553.q4lwyxmquvtjzjfz@frank-laptop
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-12-19 09:18:33 -07:00
Linus Torvalds 937d6eefc7 Here's the main documentation changes for 5.5:
- Various kerneldoc script enhancements.
 
  - More RST conversions; those are slowing down as we run out of things to
    convert, but we're a ways from done still.
 
  - Dan's "maintainer profile entry" work landed at last.  Now we just need
    to get maintainers to fill in the profiles...
 
  - A reworking of the parallel build setup to work better with a variety of
    systems (and to not take over huge systems entirely in particular).
 
  - The MAINTAINERS file is now converted to RST during the build.
    Hopefully nobody ever tries to print this thing, or they will need to
    load a lot of paper.
 
  - A script and documentation making it easy for maintainers to add Link:
    tags at commit time.
 
 Also included is the removal of a bunch of spurious CR characters.
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Merge tag 'docs-5.5a' of git://git.lwn.net/linux

Pull Documentation updates from Jonathan Corbet:
 "Here are the main documentation changes for 5.5:

   - Various kerneldoc script enhancements.

   - More RST conversions; those are slowing down as we run out of
     things to convert, but we're a ways from done still.

   - Dan's "maintainer profile entry" work landed at last. Now we just
     need to get maintainers to fill in the profiles...

   - A reworking of the parallel build setup to work better with a
     variety of systems (and to not take over huge systems entirely in
     particular).

   - The MAINTAINERS file is now converted to RST during the build.
     Hopefully nobody ever tries to print this thing, or they will need
     to load a lot of paper.

   - A script and documentation making it easy for maintainers to add
     Link: tags at commit time.

  Also included is the removal of a bunch of spurious CR characters"

* tag 'docs-5.5a' of git://git.lwn.net/linux: (91 commits)
  docs: remove a bunch of stray CRs
  docs: fix up the maintainer profile document
  libnvdimm, MAINTAINERS: Maintainer Entry Profile
  Maintainer Handbook: Maintainer Entry Profile
  MAINTAINERS: Reclaim the P: tag for Maintainer Entry Profile
  docs, parallelism: Rearrange how jobserver reservations are made
  docs, parallelism: Do not leak blocking mode to other readers
  docs, parallelism: Fix failure path and add comment
  Documentation: Remove bootmem_debug from kernel-parameters.txt
  Documentation: security: core.rst: fix warnings
  Documentation/process/howto/kokr: Update for 4.x -> 5.x versioning
  Documentation/translation: Use Korean for Korean translation title
  docs/memory-barriers.txt: Remove remaining references to mmiowb()
  docs/memory-barriers.txt/kokr: Update I/O section to be clearer about CPU vs thread
  docs/memory-barriers.txt/kokr: Fix style, spacing and grammar in I/O section
  Documentation/kokr: Kill all references to mmiowb()
  docs/memory-barriers.txt/kokr: Rewrite "KERNEL I/O BARRIER EFFECTS" section
  docs: Add initial documentation for devfreq
  Documentation: Document how to get links with git am
  docs: Add request_irq() documentation
  ...
2019-12-02 11:51:02 -08:00
Linus Torvalds 95f1fa9e34 New tracing features:
- PERAMAENT flag to ftrace_ops when attaching a callback to a function
    As /proc/sys/kernel/ftrace_enabled when set to zero will disable all
    attached callbacks in ftrace, this has a detrimental impact on live
    kernel tracing, as it disables all that it patched. If a ftrace_ops
    is registered to ftrace with the PERMANENT flag set, it will prevent
    ftrace_enabled from being disabled, and if ftrace_enabled is already
    disabled, it will prevent a ftrace_ops with PREMANENT flag set from
    being registered.
 
  - New register_ftrace_direct(). As eBPF would like to register its own
    trampolines to be called by the ftrace nop locations directly,
    without going through the ftrace trampoline, this function has been
    added. This allows for eBPF trampolines to live along side of
    ftrace, perf, kprobe and live patching. It also utilizes the ftrace
    enabled_functions file that keeps track of functions that have been
    modified in the kernel, to allow for security auditing.
 
  - Allow for kernel internal use of ftrace instances. Subsystems in
    the kernel can now create and destroy their own tracing instances
    which allows them to have their own tracing buffer, and be able
    to record events without worrying about other users from writing over
    their data.
 
  - New seq_buf_hex_dump() that lets users use the hex_dump() in their
    seq_buf usage.
 
  - Notifications now added to tracing_max_latency to allow user space
    to know when a new max latency is hit by one of the latency tracers.
 
  - Wider spread use of generic compare operations for use of bsearch and
    friends.
 
  - More synthetic event fields may be defined (32 up from 16)
 
  - Use of xarray for architectures with sparse system calls, for the
    system call trace events.
 
 This along with small clean ups and fixes.
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Merge tag 'trace-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "New tracing features:

   - New PERMANENT flag to ftrace_ops when attaching a callback to a
     function.

     As /proc/sys/kernel/ftrace_enabled when set to zero will disable
     all attached callbacks in ftrace, this has a detrimental impact on
     live kernel tracing, as it disables all that it patched. If a
     ftrace_ops is registered to ftrace with the PERMANENT flag set, it
     will prevent ftrace_enabled from being disabled, and if
     ftrace_enabled is already disabled, it will prevent a ftrace_ops
     with PREMANENT flag set from being registered.

   - New register_ftrace_direct().

     As eBPF would like to register its own trampolines to be called by
     the ftrace nop locations directly, without going through the ftrace
     trampoline, this function has been added. This allows for eBPF
     trampolines to live along side of ftrace, perf, kprobe and live
     patching. It also utilizes the ftrace enabled_functions file that
     keeps track of functions that have been modified in the kernel, to
     allow for security auditing.

   - Allow for kernel internal use of ftrace instances.

     Subsystems in the kernel can now create and destroy their own
     tracing instances which allows them to have their own tracing
     buffer, and be able to record events without worrying about other
     users from writing over their data.

   - New seq_buf_hex_dump() that lets users use the hex_dump() in their
     seq_buf usage.

   - Notifications now added to tracing_max_latency to allow user space
     to know when a new max latency is hit by one of the latency
     tracers.

   - Wider spread use of generic compare operations for use of bsearch
     and friends.

   - More synthetic event fields may be defined (32 up from 16)

   - Use of xarray for architectures with sparse system calls, for the
     system call trace events.

  This along with small clean ups and fixes"

* tag 'trace-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (51 commits)
  tracing: Enable syscall optimization for MIPS
  tracing: Use xarray for syscall trace events
  tracing: Sample module to demonstrate kernel access to Ftrace instances.
  tracing: Adding new functions for kernel access to Ftrace instances
  tracing: Fix Kconfig indentation
  ring-buffer: Fix typos in function ring_buffer_producer
  ftrace: Use BIT() macro
  ftrace: Return ENOTSUPP when DYNAMIC_FTRACE_WITH_DIRECT_CALLS is not configured
  ftrace: Rename ftrace_graph_stub to ftrace_stub_graph
  ftrace: Add a helper function to modify_ftrace_direct() to allow arch optimization
  ftrace: Add helper find_direct_entry() to consolidate code
  ftrace: Add another check for match in register_ftrace_direct()
  ftrace: Fix accounting bug with direct->count in register_ftrace_direct()
  ftrace/selftests: Fix spelling mistake "wakeing" -> "waking"
  tracing: Increase SYNTH_FIELDS_MAX for synthetic_events
  ftrace/samples: Add a sample module that implements modify_ftrace_direct()
  ftrace: Add modify_ftrace_direct()
  tracing: Add missing "inline" in stub function of latency_fsnotify()
  tracing: Remove stray tab in TRACE_EVAL_MAP_FILE's help text
  tracing: Use seq_buf_hex_dump() to dump buffers
  ...
2019-11-27 11:42:01 -08:00
Alexander Shishkin 87ff16007c intel_th: Document software sinks
Add documentation for the software sinks API of the MSU driver and the
msu-sink module in particular.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/r/20191114064201.43089-3-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-14 14:48:49 +08:00
Sebastian Andrzej Siewior 9c34fc4b7e tracing: Use CONFIG_PREEMPTION
CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT.
Both PREEMPT and PREEMPT_RT require the same functionality which today
depends on CONFIG_PREEMPT.

Add additional header output for PREEMPT_RT.
Link: http://lkml.kernel.org/r/20191015191821.11479-34-bigeasy@linutronix.de

Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13 09:37:28 -05:00
Mike Leach f0ae2cfae5 coresight: etm4x: docs: Adds detailed document for programming etm4x.
Add in detailed programmers reference for users wanting to program the
CoreSight ETM 4.x driver using sysfs.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-11-07 13:17:26 -07:00
Mike Leach 8adf42e293 coresight: docs: Create common sub-directory for coresight trace.
There are two files in the Documentation/trace directory relating to
coresight, with more to follow, so create a Documentation/trace/coresight
directory and move existing files there. Fixup index to reference
new location.

Update MAINTAINERS to reference this sub-directory rather than the
individual files.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-11-07 13:17:26 -07:00
Miroslav Benes 7162431dcf ftrace: Introduce PERMANENT ftrace_ops flag
Livepatch uses ftrace for redirection to new patched functions. It means
that if ftrace is disabled, all live patched functions are disabled as
well. Toggling global 'ftrace_enabled' sysctl thus affect it directly.
It is not a problem per se, because only administrator can set sysctl
values, but it still may be surprising.

Introduce PERMANENT ftrace_ops flag to amend this. If the
FTRACE_OPS_FL_PERMANENT is set on any ftrace ops, the tracing cannot be
disabled by disabling ftrace_enabled. Equally, a callback with the flag
set cannot be registered if ftrace_enabled is disabled.

Link: http://lkml.kernel.org/r/20191016113316.13415-2-mbenes@suse.cz

Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-04 09:33:15 -05:00
Linus Torvalds 45979a956b Tracing updates:
- Addition of multiprobes to kprobe and uprobe events
    Allows for more than one probe attached to the same location
 
  - Addition of adding immediates to probe parameters
 
  - Clean up of the recordmcount.c code. This brings us closer
    to merging recordmcount into objtool, and reuse code.
 
  - Other small clean ups
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Merge tag 'trace-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:

 - Addition of multiprobes to kprobe and uprobe events (allows for more
   than one probe attached to the same location)

 - Addition of adding immediates to probe parameters

 - Clean up of the recordmcount.c code. This brings us closer to merging
   recordmcount into objtool, and reuse code.

 - Other small clean ups

* tag 'trace-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits)
  selftests/ftrace: Update kprobe event error testcase
  tracing/probe: Reject exactly same probe event
  tracing/probe: Fix to allow user to enable events on unloaded modules
  selftests/ftrace: Select an existing function in kprobe_eventname test
  tracing/kprobe: Fix NULL pointer access in trace_porbe_unlink()
  tracing: Make sure variable reference alias has correct var_ref_idx
  tracing: Be more clever when dumping hex in __print_hex()
  ftrace: Simplify ftrace hash lookup code in clear_func_from_hash()
  tracing: Add "gfp_t" support in synthetic_events
  tracing: Rename tracing_reset() to tracing_reset_cpu()
  tracing: Document the stack trace algorithm in the comments
  tracing/arm64: Have max stack tracer handle the case of return address after data
  recordmcount: Clarify what cleanup() does
  recordmcount: Remove redundant cleanup() calls
  recordmcount: Kernel style formatting
  recordmcount: Kernel style function signature formatting
  recordmcount: Rewrite error/success handling
  selftests/ftrace: Add syntax error test for multiprobe
  selftests/ftrace: Add syntax error test for immediates
  selftests/ftrace: Add a testcase for kprobe multiprobe event
  ...
2019-09-20 11:19:48 -07:00
Peter Wu f12fcca653 docs: ftrace: clarify when tracing is disabled by the trace file
The current text could mislead the user into believing that only read()
disables tracing. Clarify that any open() call that requests read access
disables tracing.

Link: https://lkml.kernel.org/r/CAADnVQ+hU6QOC_dPmpjnuv=9g4SQEeaMEMqXOS2WpMj=q=LdiQ@mail.gmail.com
Signed-off-by: Peter Wu <peter@lekensteyn.nl>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-09-02 07:14:53 -06:00
Masami Hiramatsu 6218bf9f4d tracing/probe: Add immediate parameter support
Add immediate value parameter (\1234) support to
probe events. This allows you to specify an immediate
(or dummy) parameter instead of fetching from memory
or register.

This feature looks odd, but imagine when you put a probe
on a code to trace some data. If the code is compiled into
2 instructions and 1 instruction has a value but other has
nothing since it is optimized out.
In that case, you can not fold those into one event, even
if ftrace supported multiple probes on one event.
With this feature, you can set a dummy value like
foo=\deadbeef instead of something like foo=%di.

Link: http://lkml.kernel.org/r/156095690733.28024.13258186548822649469.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31 12:19:39 -04:00
Phong Tran fe13225fdc Documentation: coresight: convert txt to rst
This changes from plain text to reStructuredText as suggestion
in doc-guide [1]

[1] https://www.kernel.org/doc/html/latest/doc-guide/sphinx.html

Some adaptations such as: literal block, ``inline literal`` and
alignment text,...

Signed-off-by: Phong Tran <tranmanphong@gmail.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-31 13:13:45 -06:00
Linus Torvalds 818e95c768 The main changes in this release include:
- Add user space specific memory reading for kprobes
  - Allow kprobes to be executed earlier in boot
 
 The rest are mostly just various clean ups and small fixes.
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Merge tag 'trace-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "The main changes in this release include:

   - Add user space specific memory reading for kprobes

   - Allow kprobes to be executed earlier in boot

  The rest are mostly just various clean ups and small fixes"

* tag 'trace-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits)
  tracing: Make trace_get_fields() global
  tracing: Let filter_assign_type() detect FILTER_PTR_STRING
  tracing: Pass type into tracing_generic_entry_update()
  ftrace/selftest: Test if set_event/ftrace_pid exists before writing
  ftrace/selftests: Return the skip code when tracing directory not configured in kernel
  tracing/kprobe: Check registered state using kprobe
  tracing/probe: Add trace_event_call accesses APIs
  tracing/probe: Add probe event name and group name accesses APIs
  tracing/probe: Add trace flag access APIs for trace_probe
  tracing/probe: Add trace_event_file access APIs for trace_probe
  tracing/probe: Add trace_event_call register API for trace_probe
  tracing/probe: Add trace_probe init and free functions
  tracing/uprobe: Set print format when parsing command
  tracing/kprobe: Set print format right after parsed command
  kprobes: Fix to init kprobes in subsys_initcall
  tracepoint: Use struct_size() in kmalloc()
  ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS
  ftrace: Enable trampoline when rec count returns back to one
  tracing/kprobe: Do not run kprobe boot tests if kprobe_event is on cmdline
  tracing: Make a separate config for trace event self tests
  ...
2019-07-18 11:51:00 -07:00
Linus Torvalds fb4da215ed pci-v5.3-changes
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Merge tag 'pci-v5.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI updates from Bjorn Helgaas:
 "Enumeration changes:

   - Evaluate PCI Boot Configuration _DSM to learn if firmware wants us
     to preserve its resource assignments (Benjamin Herrenschmidt)

   - Simplify resource distribution (Nicholas Johnson)

   - Decode 32 GT/s link speed (Gustavo Pimentel)

  Virtualization:

   - Fix incorrect caching of VF config space size (Alex Williamson)

   - Fix VF driver probing sysfs knobs (Alex Williamson)

  Peer-to-peer DMA:

   - Fix dma_virt_ops check (Logan Gunthorpe)

  Altera host bridge driver:

   - Allow building as module (Ley Foon Tan)

  Armada 8K host bridge driver:

   - add PHYs support (Miquel Raynal)

  DesignWare host bridge driver:

   - Export APIs to support removable loadable module (Vidya Sagar)

   - Enable Relaxed Ordering erratum workaround only on Tegra20 &
     Tegra30 (Vidya Sagar)

  Hyper-V host bridge driver:

   - Fix use-after-free in eject (Dexuan Cui)

  Mobiveil host bridge driver:

   - Clean up and fix many issues, including non-identify mapped
     windows, 64-bit windows, multi-MSI, class code, INTx clearing (Hou
     Zhiqiang)

  Qualcomm host bridge driver:

   - Use clk bulk API for 2.4.0 controllers (Bjorn Andersson)

   - Add QCS404 support (Bjorn Andersson)

   - Assert PERST for at least 100ms (Niklas Cassel)

  R-Car host bridge driver:

   - Add r8a774a1 DT support (Biju Das)

  Tegra host bridge driver:

   - Add support for Gen2, opportunistic UpdateFC and ACK (PCIe protocol
     details) AER, GPIO-based PERST# (Manikanta Maddireddy)

   - Fix many issues, including power-on failure cases, interrupt
     masking in suspend, UPHY settings, AFI dynamic clock gating,
     pending DLL transactions (Manikanta Maddireddy)

  Xilinx host bridge driver:

   - Fix NWL Multi-MSI programming (Bharat Kumar Gogada)

  Endpoint support:

   - Fix 64bit BAR support (Alan Mikhak)

   - Fix pcitest build issues (Alan Mikhak, Andy Shevchenko)

  Bug fixes:

   - Fix NVIDIA GPU multi-function power dependencies (Abhishek Sahu)

   - Fix NVIDIA GPU HDA enablement issue (Lukas Wunner)

   - Ignore lockdep for sysfs "remove" (Marek Vasut)

  Misc:

   - Convert docs to reST (Changbin Du, Mauro Carvalho Chehab)"

* tag 'pci-v5.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (107 commits)
  PCI: Enable NVIDIA HDA controllers
  tools: PCI: Fix installation when `make tools/pci_install`
  PCI: dwc: pci-dra7xx: Fix compilation when !CONFIG_GPIOLIB
  PCI: Fix typos and whitespace errors
  PCI: mobiveil: Fix INTx interrupt clearing in mobiveil_pcie_isr()
  PCI: mobiveil: Fix infinite-loop in the INTx handling function
  PCI: mobiveil: Move PCIe PIO enablement out of inbound window routine
  PCI: mobiveil: Add upper 32-bit PCI base address setup in inbound window
  PCI: mobiveil: Add upper 32-bit CPU base address setup in outbound window
  PCI: mobiveil: Mask out hardcoded bits in inbound/outbound windows setup
  PCI: mobiveil: Clear the control fields before updating it
  PCI: mobiveil: Add configured inbound windows counter
  PCI: mobiveil: Fix the valid check for inbound and outbound windows
  PCI: mobiveil: Clean-up program_{ib/ob}_windows()
  PCI: mobiveil: Remove an unnecessary return value check
  PCI: mobiveil: Fix error return values
  PCI: mobiveil: Refactor the MEM/IO outbound window initialization
  PCI: mobiveil: Make some register updates more readable
  PCI: mobiveil: Reformat the code for readability
  dt-bindings: PCI: mobiveil: Change gpio_slave and apb_csr to optional
  ...
2019-07-15 20:44:49 -07:00
Mauro Carvalho Chehab 7e6294cdc0 docs: trace: add a missing blank line
Sphinx expects a blank line after a literal block markup.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-20 14:05:46 -06:00
Mauro Carvalho Chehab 151f4e2bdc docs: power: convert docs to ReST and rename to *.rst
Convert the PM documents to ReST, in order to allow them to
build with Sphinx.

The conversion is actually:
  - add blank lines and indentation in order to identify paragraphs;
  - fix tables markups;
  - add some lists markups;
  - mark literal blocks;
  - adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
2019-06-14 16:08:36 -05:00
Suzuki K Poulose cd84d63a29 Documentation: coresight: Update the generic device names
Update the documentation to reflect the new naming scheme with
latest changes.

Reported-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-14 14:43:21 -06:00
Lecopzer Chen 78a89463a3 Documentation: {u,k}probes: add tracing_on before tracing
After following the document step by step, the `cat trace` can't be
worked without enabling tracing_on and might mislead newbies about
the functionality.

Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-07 11:56:51 -06:00
Masanari Iida fe4ec72cca docs: tracing: Fix typos in histogram.rst
This patch fixes some spelling typos in histogram.rst

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-05-29 15:49:01 -06:00
Masami Hiramatsu 970988e19e tracing/kprobe: Add kprobe_event= boot parameter
Add kprobe_event= boot parameter to define kprobe events
at boot time.
The definition syntax is similar to tracefs/kprobe_events
interface, but use ',' and ';' instead of ' ' and '\n'
respectively. e.g.

  kprobe_event=p,vfs_read,$arg1,$arg2

This puts a probe on vfs_read with argument1 and 2, and
enable the new event.

Link: http://lkml.kernel.org/r/155851395498.15728.830529496248543583.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-25 23:04:43 -04:00
Masami Hiramatsu e65f7ae7f4 tracing/probe: Support user-space dereference
Support user-space dereference syntax for probe event arguments
to dereference the data-structure or array in user-space.

The syntax is just adding 'u' before an offset value.

 +|-u<OFFSET>(<FETCHARG>)

e.g. +u8(%ax), +u0(+0(%si))

For example, if you probe do_sched_setscheduler(pid, policy,
param) and record param->sched_priority, you can add new
probe as below;

 p do_sched_setscheduler priority=+u0($arg3)

Note that kprobe event provides this and it doesn't change the
dereference method automatically because we do not know whether
the given address is in userspace or kernel on some archs.

So as same as "ustring", this is an option for user, who has to
carefully choose the dereference method.

Link: http://lkml.kernel.org/r/155789872187.26965.4468456816590888687.stgit@devnote2

Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-25 23:04:42 -04:00
Masami Hiramatsu 88903c4643 tracing/probe: Add ustring type for user-space string
Add "ustring" type for fetching user-space string from kprobe event.
User can specify ustring type at uprobe event, and it is same as
"string" for uprobe.

Note that probe-event provides this option but it doesn't choose the
correct type automatically since we have not way to decide the address
is in user-space or not on some arch (and on some other arch, you can
fetch the string by "string" type). So user must carefully check the
target code (e.g. if you see __user on the target variable) and
use this new type.

Link: http://lkml.kernel.org/r/155789871009.26965.14167558859557329331.stgit@devnote2

Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-25 23:04:42 -04:00
Linus Torvalds d2d8b14604 The major changes in this tracing update includes:
- Removing of non-DYNAMIC_FTRACE from 32bit x86
 
  - Removing of mcount support from x86
 
  - Emulating a call from int3 on x86_64, fixes live kernel patching
 
  - Consolidated Tracing Error logs file
 
 Minor updates:
 
  - Removal of klp_check_compiler_support()
 
  - kdb ftrace dumping output changes
 
  - Accessing and creating ftrace instances from inside the kernel
 
  - Clean up of #define if macro
 
  - Introduction of TRACE_EVENT_NOP() to disable trace events based on config
    options
 
 And other minor fixes and clean ups
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Merge tag 'trace-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "The major changes in this tracing update includes:

   - Removal of non-DYNAMIC_FTRACE from 32bit x86

   - Removal of mcount support from x86

   - Emulating a call from int3 on x86_64, fixes live kernel patching

   - Consolidated Tracing Error logs file

  Minor updates:

   - Removal of klp_check_compiler_support()

   - kdb ftrace dumping output changes

   - Accessing and creating ftrace instances from inside the kernel

   - Clean up of #define if macro

   - Introduction of TRACE_EVENT_NOP() to disable trace events based on
     config options

  And other minor fixes and clean ups"

* tag 'trace-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits)
  x86: Hide the int3_emulate_call/jmp functions from UML
  livepatch: Remove klp_check_compiler_support()
  ftrace/x86: Remove mcount support
  ftrace/x86_32: Remove support for non DYNAMIC_FTRACE
  tracing: Simplify "if" macro code
  tracing: Fix documentation about disabling options using trace_options
  tracing: Replace kzalloc with kcalloc
  tracing: Fix partial reading of trace event's id file
  tracing: Allow RCU to run between postponed startup tests
  tracing: Fix white space issues in parse_pred() function
  tracing: Eliminate const char[] auto variables
  ring-buffer: Fix mispelling of Calculate
  tracing: probeevent: Fix to make the type of $comm string
  tracing: probeevent: Do not accumulate on ret variable
  tracing: uprobes: Re-enable $comm support for uprobe events
  ftrace/x86_64: Emulate call function while updating in breakpoint handler
  x86_64: Allow breakpoints to emulate call instructions
  x86_64: Add gap to int3 to allow for call emulation
  tracing: kdb: Allow ftdump to skip all but the last few entries
  tracing: Add trace_total_entries() / trace_total_entries_cpu()
  ...
2019-05-15 16:05:47 -07:00
Kirill Tkhai 886cf1901d mm: move recent_rotated pages calculation to shrink_inactive_list()
Patch series "mm: Generalize putback functions"]

putback_inactive_pages() and move_active_pages_to_lru() are almost
similar, so this patchset merges them ina single function.

This patch (of 4):

The patch moves the calculation from putback_inactive_pages() to
shrink_inactive_list().  This makes putback_inactive_pages() looking more
similar to move_active_pages_to_lru().

To do that, we account activated pages in reclaim_stat::nr_activate.
Since a page may change its LRU type from anon to file cache inside
shrink_page_list() (see ClearPageSwapBacked()), we have to account pages
for the both types.  So, nr_activate becomes an array.

Previously we used nr_activate to account PGACTIVATE events, but now we
account them into pgactivate variable (since they are about number of
pages in general, not about sum of hpage_nr_pages).

Link: http://lkml.kernel.org/r/155290127956.31489.3393586616054413298.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 09:47:45 -07:00
Linus Torvalds 1fb3b526df Some late arriving documentation changes. In particular, this contains the
conversion of the x86 docs to RST, which has been in the works for some
 time but needed a couple of final tweaks.
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Merge tag 'docs-5.2a' of git://git.lwn.net/linux

Pull more documentation updates from Jonathan Corbet:
 "Some late arriving documentation changes. In particular, this contains
  the conversion of the x86 docs to RST, which has been in the works for
  some time but needed a couple of final tweaks"

* tag 'docs-5.2a' of git://git.lwn.net/linux: (29 commits)
  Documentation: x86: convert x86_64/machinecheck to reST
  Documentation: x86: convert x86_64/cpu-hotplug-spec to reST
  Documentation: x86: convert x86_64/fake-numa-for-cpusets to reST
  Documentation: x86: convert x86_64/5level-paging.txt to reST
  Documentation: x86: convert x86_64/mm.txt to reST
  Documentation: x86: convert x86_64/uefi.txt to reST
  Documentation: x86: convert x86_64/boot-options.txt to reST
  Documentation: x86: convert i386/IO-APIC.txt to reST
  Documentation: x86: convert usb-legacy-support.txt to reST
  Documentation: x86: convert orc-unwinder.txt to reST
  Documentation: x86: convert resctrl_ui.txt to reST
  Documentation: x86: convert microcode.txt to reST
  Documentation: x86: convert pti.txt to reST
  Documentation: x86: convert amd-memory-encryption.txt to reST
  Documentation: x86: convert intel_mpx.txt to reST
  Documentation: x86: convert protection-keys.txt to reST
  Documentation: x86: convert pat.txt to reST
  Documentation: x86: convert mtrr.txt to reST
  Documentation: x86: convert tlb.txt to reST
  Documentation: x86: convert zero-page.txt to reST
  ...
2019-05-10 13:24:53 -04:00
Tzvetomir Stoyanov 39a39d5b6b Documentation/trace: Add clarification how histogram onmatch works
The current trace documentation, the section describing histogram's "onmatch"
is not straightforward enough about how this action is applied. It is not
clear what criteria are used to "match" both events. A short note is added,
describing what exactly is compared in order to match the events.

Signed-off-by: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[jc: fixed trivial conflict with docs-next]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-05-08 14:32:05 -06:00
Linus Torvalds 8c79f4cd44 A reasonably busy cycle for docs, including:
- Lots of work on the Chinese and Italian translations
  - Some license-rules clarifications from Christoph
  - Various build-script fixes
  - A new document on memory models
  - RST conversion of the live-patching docs
  - The usual collection of typo fixes and corrections.
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Merge tag 'docs-5.2' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "A reasonably busy cycle for docs, including:

   - Lots of work on the Chinese and Italian translations

   - Some license-rules clarifications from Christoph

   - Various build-script fixes

   - A new document on memory models

   - RST conversion of the live-patching docs

   - The usual collection of typo fixes and corrections"

* tag 'docs-5.2' of git://git.lwn.net/linux: (140 commits)
  docs/livepatch: Unify style of livepatch documentation in the ReST format
  docs: livepatch: convert docs to ReST and rename to *.rst
  scripts/documentation-file-ref-check: detect broken :doc:`foo`
  scripts/documentation-file-ref-check: don't parse Next/ dir
  LICENSES: Rename other to deprecated
  LICENSES: Clearly mark dual license only licenses
  docs: Don't reference the ZLib license in license-rules.rst
  docs/vm: Minor editorial changes in the THP and hugetlbfs
  docs/vm: add documentation of memory models
  doc:it_IT: translation alignment
  doc: fix typo in PGP guide
  dontdiff: update with Kconfig build artifacts
  docs/zh_CN: fix typos in 1.Intro.rst file
  docs/zh_CN: redirect CoC docs to Chinese version
  doc: mm: migration doesn't use FOLL_SPLIT anymore
  docs: doc-guide: remove the extension from .rst files
  doc: kselftest: Fix KBUILD_OUTPUT usage instructions
  docs: trace: fix some Sphinx warnings
  docs: speculation.txt: mark example blocks as such
  docs: ntb.txt: add blank lines to clean up some Sphinx warnings
  ...
2019-05-08 12:42:50 -07:00
Alexander Shishkin 85d49eb130 intel_th: SPDX-ify the documentation
Add the SPDX header to the Intel TH documentation.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-03 18:14:29 +02:00
Mauro Carvalho Chehab 3df5ffd2e5 docs: trace: fix some Sphinx warnings
There are some warnings produced when building trace. Fix them.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-04-16 09:08:32 -06:00
Tom Zanussi 26a9449179 tracing: Add tracing/error_log Documentation
Move most of the hist trigger extended error documentation to
ftrace.rst and expand on it to fully document tracing/error_log.

Link: http://lkml.kernel.org/r/c5d53c8f643ef6844d6ad8d0200c116936730b01.1554072478.git.tom.zanussi@linux.intel.com

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-04-08 09:22:50 -04:00
Srikar Dronamraju b689269bd1 doc: trace: Fix documentation for uprobe_profile
uprobe_profile has filename and number of probe hits information for
each uprobe event. The documentation erroneously talks about probe
mis-hits. Update the documentation to the correct information.

Link: http://lkml.kernel.org/r/1550557168-12345-1-git-send-email-srikar@linux.vnet.ibm.com

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Reported-by: KAUSTUBH RAJENDRA WELANKAR <f20160095@hyderabad.bits-pilani.ac.in>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-21 10:28:55 -05:00
Tom Zanussi e91eefd731 tracing: Add alternative synthetic event trace action syntax
Add a 'trace(synthetic_event_name, params)' alternative to
synthetic_event_name(params).

Currently, the syntax used for generating synthetic events is to
invoke synthetic_event_name(params) i.e. use the synthetic event name
as a function call.

Users requested a new form that more explicitly shows that the
synthetic event is in effect being traced.  In this version, a new
'trace()' keyword is used, and the synthetic event name is passed in
as the first argument.

In addition, for the sake of consistency with other actions, change
the documention to emphasize the trace() form over the function-call
form, which remains documented as equivalent.

Link: http://lkml.kernel.org/r/d082773e50232a001480cf837679a1e01c1a2eb7.1550100284.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-20 13:51:07 -05:00
Tom Zanussi ff0d35e2e1 tracing: Add hist trigger onchange() handler Documentation
Add Documentation for the hist:onchange($var) handler.

Link: http://lkml.kernel.org/r/ab54b7383b265609fda52648a8fbfbd2631a640f.1550100284.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-20 13:51:07 -05:00
Tom Zanussi fd451a3d92 tracing: Add hist trigger snapshot() action Documentation
Add Documentation for the hist:handlerXXX($var).snapshot() action.

Link: http://lkml.kernel.org/r/445861d7822cd4b6aeaea1cecfcdbda466502148.1550100284.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-20 13:51:07 -05:00
Tom Zanussi 5032b38189 tracing: Make hist trigger Documentation better reflect actions/handlers
The action/handler code refactoring didn't change the action/handler
syntax, but did generalize it - the Documentation should reflect that.

Link: http://lkml.kernel.org/r/c2fe4144678829c70cad67aaa847dca27d57cb83.1550100284.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-20 13:51:06 -05:00
Steven Rostedt (VMware) f79b3f3385 ftrace: Allow enabling of filters via index of available_filter_functions
Enabling of large number of functions by echoing in a large subset of the
functions in available_filter_functions can take a very long time. The
process requires testing all functions registered by the function tracer
(which is in the 10s of thousands), and doing a kallsyms lookup to convert
the ip address into a name, then comparing that name with the string passed
in.

When a function causes the function tracer to crash the system, a binary
bisect of the available_filter_functions can be done to find the culprit.
But this requires passing in half of the functions in
available_filter_functions over and over again, which makes it basically a
O(n^2) operation. With 40,000 functions, that ends up bing 1,600,000,000
opertions! And enabling this can take over 20 minutes.

As a quick speed up, if a number is passed into one of the filter files,
instead of doing a search, it just enables the function at the corresponding
line of the available_filter_functions file. That is:

 # echo 50 > set_ftrace_filter
 # cat set_ftrace_filter
 x86_pmu_commit_txn

 # head -50 available_filter_functions | tail -1
 x86_pmu_commit_txn

This allows setting of half the available_filter_functions to take place in
less than a second!

 # time seq 20000 > set_ftrace_filter
 real    0m0.042s
 user    0m0.005s
 sys     0m0.015s

 # wc -l set_ftrace_filter
 20000 set_ftrace_filter

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-15 13:10:09 -05:00
Changbin Du 88d380eb06 tracing/doc: Add latency tracer funcgraph example
This add an example about how to use funcgraph with latency tracers.

Link: http://lkml.kernel.org/r/20190101154614.8887-6-changbin.du@gmail.com

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-06 11:56:19 -05:00
Rafael J. Wysocki 343e60e52a Merge branches 'pm-cpuidle', 'pm-cpufreq' and 'pm-sleep'
* pm-cpuidle:
  doc: trace: fix reference to cpuidle documentation file
  cpuidle / Documentation: Update cpuidle MAINTAINERS entry

* pm-cpufreq:
  cpufreq: scmi: Fix frequency invariance in slow path
  cpufreq: check if policy is inactive early in __cpufreq_get()
  cpufreq: scpi/scmi: Fix freeing of dynamic OPPs
  cpufreq / Documentation: Update cpufreq MAINTAINERS entry

* pm-sleep:
  PM: sleep: call devfreq suspend/resume
2019-01-11 10:09:51 +01:00
Otto Sabart 7604bf0920 doc: trace: fix reference to cpuidle documentation file
Old cpuidle/sysfs.txt file was replaced in aa5eee355b. So, refer to
an updated file.

Fixes: aa5eee355b (Documentation: admin-guide: PM: Add cpuidle document)
Signed-off-by: Otto Sabart <ottosabart@seberm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-01-09 11:44:30 +01:00
Linus Torvalds 495d714ad1 Tracing changes for v4.21:
- Rework of the kprobe/uprobe and synthetic events to consolidate all
    the dynamic event code. This will make changes in the future easier.
 
  - Partial rewrite of the function graph tracing infrastructure.
    This will allow for multiple users of hooking onto functions
    to get the callback (return) of the function. This is the ground
    work for having kprobes and function graph tracer using one code base.
 
  - Clean up of the histogram code that will facilitate adding more
    features to the histograms in the future.
 
  - Addition of str_has_prefix() and a few use cases. There currently
    is a similar function strstart() that is used in a few places, but
    only returns a bool and not a length. These instances will be
    removed in the future to use str_has_prefix() instead.
 
  - A few other various clean ups as well.
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Merge tag 'trace-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:

 - Rework of the kprobe/uprobe and synthetic events to consolidate all
   the dynamic event code. This will make changes in the future easier.

 - Partial rewrite of the function graph tracing infrastructure. This
   will allow for multiple users of hooking onto functions to get the
   callback (return) of the function. This is the ground work for having
   kprobes and function graph tracer using one code base.

 - Clean up of the histogram code that will facilitate adding more
   features to the histograms in the future.

 - Addition of str_has_prefix() and a few use cases. There currently is
   a similar function strstart() that is used in a few places, but only
   returns a bool and not a length. These instances will be removed in
   the future to use str_has_prefix() instead.

 - A few other various clean ups as well.

* tag 'trace-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (57 commits)
  tracing: Use the return of str_has_prefix() to remove open coded numbers
  tracing: Have the historgram use the result of str_has_prefix() for len of prefix
  tracing: Use str_has_prefix() instead of using fixed sizes
  tracing: Use str_has_prefix() helper for histogram code
  string.h: Add str_has_prefix() helper function
  tracing: Make function ‘ftrace_exports’ static
  tracing: Simplify printf'ing in seq_print_sym
  tracing: Avoid -Wformat-nonliteral warning
  tracing: Merge seq_print_sym_short() and seq_print_sym_offset()
  tracing: Add hist trigger comments for variable-related fields
  tracing: Remove hist trigger synth_var_refs
  tracing: Use hist trigger's var_ref array to destroy var_refs
  tracing: Remove open-coding of hist trigger var_ref management
  tracing: Use var_refs[] for hist trigger reference checking
  tracing: Change strlen to sizeof for hist trigger static strings
  tracing: Remove unnecessary hist trigger struct field
  tracing: Fix ftrace_graph_get_ret_stack() to use task and not current
  seq_buf: Use size_t for len in seq_buf_puts()
  seq_buf: Make seq_buf_puts() null-terminate the buffer
  arm64: Use ftrace_graph_get_ret_stack() instead of curr_ret_stack
  ...
2018-12-31 11:46:59 -08:00
Linus Torvalds 3868772b99 A fairly normal cycle for documentation stuff. We have a new
document on perf security, more Italian translations, more
 improvements to the memory-management docs, improvements to the
 pathname lookup documentation, and the usual array of smaller
 fixes.
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Merge tag 'docs-5.0' of git://git.lwn.net/linux

Pull documentation update from Jonathan Corbet:
 "A fairly normal cycle for documentation stuff. We have a new document
  on perf security, more Italian translations, more improvements to the
  memory-management docs, improvements to the pathname lookup
  documentation, and the usual array of smaller fixes.

  As is often the case, there are a few reaches outside of
  Documentation/ to adjust kerneldoc comments"

* tag 'docs-5.0' of git://git.lwn.net/linux: (38 commits)
  docs: improve pathname-lookup document structure
  configfs: fix wrong name of struct in documentation
  docs/mm-api: link slab_common.c to "The Slab Cache" section
  slab: make kmem_cache_create{_usercopy} description proper kernel-doc
  doc:process: add links where missing
  docs/core-api: make mm-api.rst more structured
  x86, boot: documentation whitespace fixup
  Documentation: devres: note checking needs when converting
  doc🇮🇹 add some process/* translations
  doc🇮🇹 fixes in process/1.Intro
  Documentation: convert path-lookup from markdown to resturctured text
  Documentation/admin-guide: update admin-guide index.rst
  Documentation/admin-guide: introduce perf-security.rst file
  scripts/kernel-doc: Fix struct and struct field attribute processing
  Documentation: dev-tools: Fix typos in index.rst
  Correct gen_init_cpio tool's documentation
  Document /proc/pid PID reuse behavior
  Documentation: update path-lookup.md for parallel lookups
  Documentation: Use "while" instead of "whilst"
  dmaengine: Add mailing list address to the documentation
  ...
2018-12-29 11:21:49 -08:00
Alexander Shishkin 4cdd41585c stm class: Add a reference to the SyS-T document
Commit 4cb3653df0 ("stm class: Document the MIPI SyS-T protocol usage")
added a document describing the SyS-T protocol usage, but forgot to add
it to the directory index. Fix that.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Fixes: 4cb3653df0 ("stm class: Document the MIPI SyS-T protocol usage")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-19 20:21:06 +01:00
Masami Hiramatsu 0597c49c69 tracing/uprobes: Use dyn_event framework for uprobe events
Use dyn_event framework for uprobe events. This shows
uprobe events on "dynamic_events" file.
User can also define new uprobe events via dynamic_events.

Link: http://lkml.kernel.org/r/154140858481.17322.9091293846515154065.stgit@devbox

Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:10 -05:00
Masami Hiramatsu 6212dd2968 tracing/kprobes: Use dyn_event framework for kprobe events
Use dyn_event framework for kprobe events. This shows
kprobe events on "tracing/dynamic_events" file.

User can also define new events via tracing/dynamic_events.

Link: http://lkml.kernel.org/r/154140855646.17322.6619219995865980392.stgit@devbox

Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:09 -05:00
Amir Livneh 2a1e03ca33 doc: tracing: Fix a number of typos
Trivial fixes to spelling mistakes in ftrace.rst

v2: tripple -> triple

Signed-off-by: Amir Livneh <alivneh@fb.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-11-07 15:52:39 -07:00
Linus Torvalds 343a9f3540 The biggest change here is the updates to kprobes
Back in January I posted patches to create function based events. These were
 the events that you suggested I make to allow developers to easily create
 events in code where no trace event exists. After posting those changes for
 review, it was suggested that we implement this instead with kprobes.
 
 The problem with kprobes is that the interface is too complex and needs to
 be simplified. Masami Hiramatsu posted patches in March and I've been
 playing with them a bit. There's been a bit of clean up in the kprobe code
 that was inspired by the function based event patches, and a couple of
 enhancements to the kprobe event interface.
 
  - If the arch supports it (we added support for x86), you can place a
    kprobe event at the start of a function and use $arg1, $arg2, etc
    to reference the arguments of a function. (Before you needed to know
    what register or where on the stack the argument was).
 
  - The second is a way to see array of events. For example, if you reference
    a mac address, you can add:
 
    echo 'p:mac ip_rcv perm_addr=+574($arg2):x8[6]' > kprobe_events
 
    And this will produce:
 
    mac: (ip_rcv+0x0/0x140) perm_addr={0x52,0x54,0x0,0xc0,0x76,0xec}
 
 Other changes include
 
  - Exporting trace_dump_stack to modules
 
  - Have the stack tracer trace the entire stack (stop trying to remove
    tracing itself, as we keep removing too much).
 
  - Added support for SDT in uprobes
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Merge tag 'trace-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "The biggest change here is the updates to kprobes

  Back in January I posted patches to create function based events.
  These were the events that you suggested I make to allow developers to
  easily create events in code where no trace event exists. After
  posting those changes for review, it was suggested that we implement
  this instead with kprobes.

  The problem with kprobes is that the interface is too complex and
  needs to be simplified. Masami Hiramatsu posted patches in March and
  I've been playing with them a bit. There's been a bit of clean up in
  the kprobe code that was inspired by the function based event patches,
  and a couple of enhancements to the kprobe event interface.

   - If the arch supports it (we added support for x86), you can place a
     kprobe event at the start of a function and use $arg1, $arg2, etc
     to reference the arguments of a function. (Before you needed to
     know what register or where on the stack the argument was).

   - The second is a way to see array of events. For example, if you
     reference a mac address, you can add:

	echo 'p:mac ip_rcv perm_addr=+574($arg2):x8[6]' > kprobe_events

     And this will produce:

	mac: (ip_rcv+0x0/0x140) perm_addr={0x52,0x54,0x0,0xc0,0x76,0xec}

  Other changes include

   - Exporting trace_dump_stack to modules

   - Have the stack tracer trace the entire stack (stop trying to remove
     tracing itself, as we keep removing too much).

   - Added support for SDT in uprobes"

[ SDT - "Statically Defined Tracing" are userspace markers for tracing.
  Let's not use random TLA's in explanations unless they are fairly
  well-established as generic (at least for kernel people) - Linus ]

* tag 'trace-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (24 commits)
  tracing: Have stack tracer trace full stack
  tracing: Export trace_dump_stack to modules
  tracing: probeevent: Fix uninitialized used of offset in parse args
  tracing/kprobes: Allow kprobe-events to record module symbol
  tracing/kprobes: Check the probe on unloaded module correctly
  tracing/uprobes: Fix to return -EFAULT if copy_from_user failed
  tracing: probeevent: Add $argN for accessing function args
  x86: ptrace: Add function argument access API
  tracing: probeevent: Add array type support
  tracing: probeevent: Add symbol type
  tracing: probeevent: Unify fetch_insn processing common part
  tracing: probeevent: Append traceprobe_ for exported function
  tracing: probeevent: Return consumed bytes of dynamic area
  tracing: probeevent: Unify fetch type tables
  tracing: probeevent: Introduce new argument fetching code
  tracing: probeevent: Remove NOKPROBE_SYMBOL from print functions
  tracing: probeevent: Cleanup argument field definition
  tracing: probeevent: Cleanup print argument functions
  trace_uprobe: support reference counter in fd-based uprobe
  perf probe: Support SDT markers having reference counter (semaphore)
  ...
2018-10-30 09:49:56 -07:00
Linus Torvalds 18d0eae30e Char/Misc driver patches for 4.20-rc1
Here is the big set of char/misc patches for 4.20-rc1.
 
 Loads of things here, we have new code in all of these driver
 subsystems:
 	fpga
 	stm
 	extcon
 	nvmem
 	eeprom
 	hyper-v
 	gsmi
 	coresight
 	thunderbolt
 	vmw_balloon
 	goldfish
 	soundwire
 
 along with lots of fixes and minor changes to other small drivers.
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here is the big set of char/misc patches for 4.20-rc1.

  Loads of things here, we have new code in all of these driver
  subsystems:
   - fpga
   - stm
   - extcon
   - nvmem
   - eeprom
   - hyper-v
   - gsmi
   - coresight
   - thunderbolt
   - vmw_balloon
   - goldfish
   - soundwire
  along with lots of fixes and minor changes to other small drivers.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (245 commits)
  Documentation/security-bugs: Clarify treatment of embargoed information
  lib: Fix ia64 bootloader linkage
  MAINTAINERS: Clarify UIO vs UIOVEC maintainer
  docs/uio: fix a grammar nitpick
  docs: fpga: document programming fpgas using regions
  fpga: add devm_fpga_region_create
  fpga: bridge: add devm_fpga_bridge_create
  fpga: mgr: add devm_fpga_mgr_create
  hv_balloon: Replace spin_is_locked() with lockdep
  sgi-xp: Replace spin_is_locked() with lockdep
  eeprom: New ee1004 driver for DDR4 memory
  eeprom: at25: remove unneeded 'at25_remove'
  w1: IAD Register is yet readable trough iad sys file. Fix snprintf (%u for unsigned, count for max size).
  misc: mic: scif: remove set but not used variables 'src_dma_addr, dst_dma_addr'
  misc: mic: fix a DMA pool free failure
  platform: goldfish: pipe: Add a blank line to separate varibles and code
  platform: goldfish: pipe: Remove redundant casting
  platform: goldfish: pipe: Call misc_deregister if init fails
  platform: goldfish: pipe: Move the file-scope goldfish_pipe_dev variable into the driver state
  platform: goldfish: pipe: Move the file-scope goldfish_pipe_miscdev variable into the driver state
  ...
2018-10-26 09:11:43 -07:00
Masanari Iida aea74de4b2 docs: Fix typos in histogram.rst
This patch fixes some spelling typos.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-10-18 12:33:08 -06:00
Alexander Shishkin 60e6f6d50f stm class: SPDX-ify the documentation
Add the SPDX header to the STM class documentation.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-11 12:12:55 +02:00
Alexander Shishkin 3ef230370e stm class: Update documentation to match the new identification rules
The rules and order of identification of trace sources against the
"stp-policy" have changed; update the documentation to reflect that.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-11 12:12:55 +02:00
Alexander Shishkin 4cb3653df0 stm class: Document the MIPI SyS-T protocol usage
Add a document describing MIPI SyS-T protocol driver usage.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-11 12:12:55 +02:00
Masami Hiramatsu a1303af5d7 tracing: probeevent: Add $argN for accessing function args
Add $argN special fetch variable for accessing function
arguments. This allows user to trace the Nth argument easily
at the function entry.

Note that this returns most probably assignment of registers
and stacks. In some case, it may not work well. If you need
to access correct registers or stacks you should use perf-probe.

Link: http://lkml.kernel.org/r/152465888632.26224.3412465701570253696.stgit@devbox

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-10 22:19:11 -04:00
Masami Hiramatsu 40b53b7718 tracing: probeevent: Add array type support
Add array type support for probe events.
This allows user to get arraied types from memory address.
The array type syntax is

	TYPE[N]

Where TYPE is one of types (u8/16/32/64,s8/16/32/64,
x8/16/32/64, symbol, string) and N is a fixed value less
than 64.

The string array type is a bit different from other types. For
other base types, <base-type>[1] is equal to <base-type>
(e.g. +0(%di):x32[1] is same as +0(%di):x32.) But string[1] is not
equal to string. The string type itself represents "char array",
but string array type represents "char * array". So, for example,
+0(%di):string[1] is equal to +0(+0(%di)):string.

Link: http://lkml.kernel.org/r/152465891533.26224.6150658225601339931.stgit@devbox

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-10 22:19:10 -04:00
Masami Hiramatsu 60c2e0cebf tracing: probeevent: Add symbol type
Add "symbol" type to probeevent, which is an alias of u32 or u64
(depends on BITS_PER_LONG). This shows the result value in
symbol+offset style. This type is only available with kprobe
events.

Link: http://lkml.kernel.org/r/152465882860.26224.14779072294412467338.stgit@devbox

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-10 22:19:10 -04:00
Masami Hiramatsu 8a2933cfe7 docs: tracing: Add stacktrace filter command
Add a description of stacktrace filter command.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-08-31 16:34:49 -06:00
Linus Torvalds e6ecec342f This was a moderately busy cycle for docs, with the usual collection of
small fixes and updates.  We also have new ktime_get_*() docs from Arnd,
 some kernel-doc fixes, a new set of Italian translations (non so se vale la
 pena, ma non fa male - speriamo bene), and some extensive early
 memory-management documentation improvements from Mike Rapoport.
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Merge tag 'docs-4.19' of git://git.lwn.net/linux

Pull documentation update from Jonathan Corbet:
 "This was a moderately busy cycle for docs, with the usual collection
  of small fixes and updates.

  We also have new ktime_get_*() docs from Arnd, some kernel-doc fixes,
  a new set of Italian translations (non so se vale la pena, ma non fa
  male - speriamo bene), and some extensive early memory-management
  documentation improvements from Mike Rapoport"

* tag 'docs-4.19' of git://git.lwn.net/linux: (52 commits)
  Documentation: corrections to console/console.txt
  Documentation: add ioctl number entry for v4l2-subdev.h
  Remove gendered language from management style documentation
  scripts/kernel-doc: Escape all literal braces in regexes
  docs/mm: add description of boot time memory management
  docs/mm: memblock: add overview documentation
  docs/mm: memblock: add kernel-doc description for memblock types
  docs/mm: memblock: add kernel-doc comments for memblock_add[_node]
  docs/mm: memblock: update kernel-doc comments
  mm/memblock: add a name for memblock flags enumeration
  docs/mm: bootmem: add overview documentation
  docs/mm: bootmem: add kernel-doc description of 'struct bootmem_data'
  docs/mm: bootmem: fix kernel-doc warnings
  docs/mm: nobootmem: fixup kernel-doc comments
  mm/bootmem: drop duplicated kernel-doc comments
  Documentation: vm.txt: Adding 'nr_hugepages_mempolicy' parameter description.
  doc:it_IT: translation for kernel-hacking
  docs: Fix the reference labels in Locking.rst
  doc: tracing: Fix a typo of trace_stat
  mm: Introduce new type vm_fault_t
  ...
2018-08-14 14:29:31 -07:00
Masami Hiramatsu 1fee4f7752 doc: tracing: Fix a typo of trace_stat
The name of the directory for per-cpu function statistics
is trace_stat, not trace_stats.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-07-26 15:48:10 -06:00
Ruchi Kandoi 601b218568 cpufreq: trace frequency limits change
systrace used for tracing for Android systems has carried a patch for
many years in the Android tree that traces when the cpufreq limits
change.  With the help of this information, systrace can know when the
policy limits change and can visually display the data. Lets add
upstream support for the same.

Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-07-26 10:17:47 +02:00
Andreas Ziegler 31130c8ec8 Documentation: kprobetrace: document 'trigger' file
As the other files are documented explicitly, let's add a
short description for 'trigger' as well.

Signed-off-by: Andreas Ziegler <andreas.ziegler@fau.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-07-23 09:26:42 -06:00
Andreas Ziegler e50891d6ef Documentation: {u,k}probes: fix filename for event enabling
The per-event files to enable or disable kprobes and uprobes
are named 'enable', not 'enabled'. Fix the corresponding
documentation.

Signed-off-by: Andreas Ziegler <andreas.ziegler@fau.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-07-23 09:26:37 -06:00
Mauro Carvalho Chehab ea272257cc docs: histogram.txt: convert it to ReST file format
Despite being mentioned at Documentation/trace/ftrace.rst as a
rst file, this file was still a text one, with several issues.

Convert it to ReST and add it to the trace index:
- Mark the document title as such;
- Identify and indent the literal blocks;
- Use the proper markups for table.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-07-02 11:26:02 -06:00
Joel Fernandes (Google) 064f35a952 tracing: Fix some errors in histogram documentation
Fix typos, inconsistencies in using quotes, incorrect section number,
etc. in the trace histogram documentation.

Link: http://lkml.kernel.org/r/20180614224859.55864-1-joel@joelfernandes.org

Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-06-21 15:12:44 -04:00
Mauro Carvalho Chehab 5fb94e9ca3 docs: Fix some broken references
As we move stuff around, some doc references are broken. Fix some of
them via this script:
	./scripts/documentation-file-ref-check --fix

Manually checked if the produced result is valid, removing a few
false-positives.

Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Coly Li <colyli@suse.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>
2018-06-15 18:10:01 -03:00
Mauro Carvalho Chehab ec15872daa docs: fix broken references with multiple hints
The script:
	./scripts/documentation-file-ref-check --fix

Gives multiple hints for broken references on some files.
Manually use the one that applies for some files.

Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: James Morris <james.morris@microsoft.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>
2018-06-15 18:10:01 -03:00
Linus Torvalds 5eb6eed7e0 One new feature was added to ftrace, which is the trace_marker now supports
triggers. For example:
 
   # cd /sys/kernel/debug/tracing
   # echo 'snapshot' > events/ftrace/print/trigger
   # echo 'cause snapshot' > trace_marker
 
 The rest of the changes are various clean ups and also one stable fix that
 was added late in the cycle.
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Merge tag 'trace-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "One new feature was added to ftrace, which is the trace_marker now
  supports triggers. For example:

    # cd /sys/kernel/debug/tracing
    # echo 'snapshot' > events/ftrace/print/trigger
    # echo 'cause snapshot' > trace_marker

  The rest of the changes are various clean ups and also one stable fix
  that was added late in the cycle"

* tag 'trace-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (21 commits)
  tracing: Use match_string() instead of open coding it in trace_set_options()
  branch-check: fix long->int truncation when profiling branches
  ring-buffer: Fix typo in comment
  ring-buffer: Fix a bunch of typos in comments
  tracing/selftest: Add test to test simple snapshot trigger for trace_marker
  tracing/selftest: Add test to test hist trigger between kernel event and trace_marker
  tracing/selftest: Add selftests to test trace_marker histogram triggers
  ftrace/selftest: Fix reset_trigger() to handle triggers with filters
  ftrace/selftest: Have the reset_trigger code be a bit more careful
  tracing: Document trace_marker triggers
  tracing: Allow histogram triggers to access ftrace internal events
  tracing: Prevent further users of zero size static arrays in trace events
  tracing: Have zero size length in filter logic be full string
  tracing: Add trigger file for trace_markers tracefs/ftrace/print
  tracing: Do not show filter file for ftrace internal events
  tracing: Add brackets in ftrace event dynamic arrays
  tracing: Have event_trace_init() called by trace_init_tracefs()
  tracing: Add __find_event_file() to find event files without restrictions
  tracing: Do not reference event data in post call triggers
  tracepoints: Fix the descriptions of tracepoint_probe_register{_prio}
  ...
2018-06-06 16:39:18 -07:00
Linus Torvalds abf7dba7c4 Char/Misc driver patches for 4.18-rc1
Here is the "big" char and misc driver patches for 4.18-rc1.
 
 It's not a lot of stuff here, but there are some highlights:
 	- coreboot driver updates
 	- soundwire driver updates
 	- android binder updates
 	- fpga big sync, mostly documentation
 	- lots of minor driver updates
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here is the "big" char and misc driver patches for 4.18-rc1.

  It's not a lot of stuff here, but there are some highlights:

   - coreboot driver updates

   - soundwire driver updates

   - android binder updates

   - fpga big sync, mostly documentation

   - lots of minor driver updates

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (81 commits)
  vmw_balloon: fixing double free when batching mode is off
  MAINTAINERS: Add driver-api/fpga path
  fpga: clarify that unregister functions also free
  documentation: fpga: move fpga-region.txt to driver-api
  documentation: fpga: add bridge document to driver-api
  documentation: fpga: move fpga-mgr.txt to driver-api
  Documentation: fpga: move fpga overview to driver-api
  fpga: region: kernel-doc fixes
  fpga: bridge: kernel-doc fixes
  fpga: mgr: kernel-doc fixes
  fpga: use SPDX
  fpga: region: change api, add fpga_region_create/free
  fpga: bridge: change api, don't use drvdata
  fpga: manager: change api, don't use drvdata
  fpga: region: don't use drvdata in common fpga code
  Drivers: hv: vmbus: Removed an unnecessary cast from void *
  ver_linux: Drop redundant calls to system() to test if file is readable
  ver_linux: Move stderr redirection from function parameter to function body
  misc: IBM Virtual Management Channel Driver (VMC)
  rpmsg: Correct support for MODULE_DEVICE_TABLE()
  ...
2018-06-05 16:20:22 -07:00
Linus Torvalds eeee3149aa There's been a fair amount of work in the docs tree this time around,
including:
 
  - Extensive RST conversions and organizational work in the
    memory-management docs thanks to Mike Rapoport.
 
  - An update of Documentation/features from Andrea Parri and a script to
    keep it updated.
 
  - Various LICENSES updates from Thomas, along with a script to check SPDX
    tags.
 
  - Work to fix dangling references to documentation files; this involved a
    fair number of one-liner comment changes outside of Documentation/
 
 ...and the usual list of documentation improvements, typo fixes, etc.
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Merge tag 'docs-4.18' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "There's been a fair amount of work in the docs tree this time around,
  including:

   - Extensive RST conversions and organizational work in the
     memory-management docs thanks to Mike Rapoport.

   - An update of Documentation/features from Andrea Parri and a script
     to keep it updated.

   - Various LICENSES updates from Thomas, along with a script to check
     SPDX tags.

   - Work to fix dangling references to documentation files; this
     involved a fair number of one-liner comment changes outside of
     Documentation/

  ... and the usual list of documentation improvements, typo fixes, etc"

* tag 'docs-4.18' of git://git.lwn.net/linux: (103 commits)
  Documentation: document hung_task_panic kernel parameter
  docs/admin-guide/mm: add high level concepts overview
  docs/vm: move ksm and transhuge from "user" to "internals" section.
  docs: Use the kerneldoc comments for memalloc_no*()
  doc: document scope NOFS, NOIO APIs
  docs: update kernel versions and dates in tables
  docs/vm: transhuge: split userspace bits to admin-guide/mm/transhuge
  docs/vm: transhuge: minor updates
  docs/vm: transhuge: change sections order
  Documentation: arm: clean up Marvell Berlin family info
  Documentation: gpio: driver: Fix a typo and some odd grammar
  docs: ranoops.rst: fix location of ramoops.txt
  scripts/documentation-file-ref-check: rewrite it in perl with auto-fix mode
  docs: uio-howto.rst: use a code block to solve a warning
  mm, THP, doc: Add document for thp_swpout/thp_swpout_fallback
  w1: w1_io.c: fix a kernel-doc warning
  Documentation/process/posting: wrap text at 80 cols
  docs: admin-guide: add cgroup-v2 documentation
  Revert "Documentation/features/vm: Remove arch support status file for 'pte_special'"
  Documentation: refcount-vs-atomic: Update reference to LKMM doc.
  ...
2018-06-04 12:34:27 -07:00
Steven Rostedt (VMware) d3439f9d6c tracing: Document trace_marker triggers
Add documentation and an example on how to use trace_marker triggers.

Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-05-29 08:29:30 -04:00
Leo Yan 40fe78a242 coresight: Remove %px for printing pcsr value
The driver prints pcsr twice: the first time it uses specifier %px to
print hexadecimal pcsr value and the second time uses specifier %pS for
output kernel symbols.

As suggested by Kees, using %pS should be sufficient and %px isn't
necessary; the reason is if the pcsr is a kernel space address, we can
easily get to know the code line from %pS format, on the other hand, if
the pcsr value doesn't fall into kernel space range (e.g. if the CPU is
stuck in firmware), %pS also gives out pcsr hexadecimal value.

So this commit removes useless %px and update section "Output format"
in the document for alignment between the code and document.

Suggested-by: Kees Cook <keescook@chromium.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14 16:20:00 +02:00
Mathieu Poirier 87bf4d68a4 coresight: Grouping all perf tools oriented section together
This patch groups together section pertaining to the perf tools.  That way
everything is at the same place rather than spread out.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-27 17:00:28 -06:00
Mathieu Poirier f29816b496 coresight: Add section for integration with the perf tools
Adding a section that document how to use the Coresight framework and
drivers from the perf tools.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-27 17:00:04 -06:00
Mathieu Poirier 10c2c55d9f coresight: Remove obsolete reference to "owner" in CoreSight descriptor
Field "owner" of struct coresight_desc has been removed a while back but
the documentation was not updated to reflect the changes.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-27 16:59:47 -06:00
Masanari Iida e37274fa3a linux-next: ftrace/docs: Fix spelling typos in ftrace-users.rst
This patch corrects some spelling typo in ftrace-users.rst

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-27 16:31:13 -06:00
Thomas Gleixner a3ed0e4393 Revert: Unify CLOCK_MONOTONIC and CLOCK_BOOTTIME
Revert commits

92af4dcb4e ("tracing: Unify the "boot" and "mono" tracing clocks")
127bfa5f43 ("hrtimer: Unify MONOTONIC and BOOTTIME clock behavior")
7250a4047a ("posix-timers: Unify MONOTONIC and BOOTTIME clock behavior")
d6c7270e91 ("timekeeping: Remove boot time specific code")
f2d6fdbfd2 ("Input: Evdev - unify MONOTONIC and BOOTTIME clock behavior")
d6ed449afd ("timekeeping: Make the MONOTONIC clock behave like the BOOTTIME clock")
72199320d4 ("timekeeping: Add the new CLOCK_MONOTONIC_ACTIVE clock")

As stated in the pull request for the unification of CLOCK_MONOTONIC and
CLOCK_BOOTTIME, it was clear that we might have to revert the change.

As reported by several folks systemd and other applications rely on the
documented behaviour of CLOCK_MONOTONIC on Linux and break with the above
changes. After resume daemons time out and other timeout related issues are
observed. Rafael compiled this list:

* systemd kills daemons on resume, after >WatchdogSec seconds
  of suspending (Genki Sky).  [Verified that that's because systemd uses
  CLOCK_MONOTONIC and expects it to not include the suspend time.]

* systemd-journald misbehaves after resume:
  systemd-journald[7266]: File /var/log/journal/016627c3c4784cd4812d4b7e96a34226/system.journal
corrupted or uncleanly shut down, renaming and replacing.
  (Mike Galbraith).

* NetworkManager reports "networking disabled" and networking is broken
  after resume 50% of the time (Pavel).  [May be because of systemd.]

* MATE desktop dims the display and starts the screensaver right after
  system resume (Pavel).

* Full system hang during resume (me).  [May be due to systemd or NM or both.]

That happens on debian and open suse systems.

It's sad, that these problems were neither catched in -next nor by those
folks who expressed interest in this change.

Reported-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Reported-by: Genki Sky <sky@genki.is>,
Reported-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kevin Easton <kevin@guarana.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salyzyn <salyzyn@android.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
2018-04-26 14:53:32 +02:00
Steffen Maier 32fb7ef69a Documentation: ftrace: clarify filters with dynamic ftrace and graph
I fell into the trap of having set up function tracer with a very
limited filter and then switched over to function_graph and was
erroneously wondering why the latter did not trace what I expected,
which was the full unabridged graph recursion.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-04-16 14:04:26 -06:00
Linus Torvalds 2a56bb596b New features:
- Tom Zanussi's extended histogram work
    This adds the synthetic events to have histograms from multiple event data
    Adds triggers "onmatch" and "onmax" to call the synthetic events
    Several updates to the histogram code from this
 
  - Allow way to nest ring buffer calls in the same context
 
  - Allow absolute time stamps in ring buffer
 
  - Rewrite of filter code parsing based on Al Viro's suggestions
 
  - Setting of trace_clock to global if TSC is unstable (on boot)
 
  - Better OOM handling when allocating large ring buffers
 
  - Added initcall tracepoints (consolidated initcall_debug code with them)
 
 And other various fixes and clean ups
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Merge tag 'trace-v4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "New features:

   - Tom Zanussi's extended histogram work.

     This adds the synthetic events to have histograms from multiple
     event data Adds triggers "onmatch" and "onmax" to call the
     synthetic events Several updates to the histogram code from this

   - Allow way to nest ring buffer calls in the same context

   - Allow absolute time stamps in ring buffer

   - Rewrite of filter code parsing based on Al Viro's suggestions

   - Setting of trace_clock to global if TSC is unstable (on boot)

   - Better OOM handling when allocating large ring buffers

   - Added initcall tracepoints (consolidated initcall_debug code with
     them)

  And other various fixes and clean ups"

* tag 'trace-v4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (68 commits)
  init: Have initcall_debug still work without CONFIG_TRACEPOINTS
  init, tracing: Have printk come through the trace events for initcall_debug
  init, tracing: instrument security and console initcall trace events
  init, tracing: Add initcall trace events
  tracing: Add rcu dereference annotation for test func that touches filter->prog
  tracing: Add rcu dereference annotation for filter->prog
  tracing: Fixup logic inversion on setting trace_global_clock defaults
  tracing: Hide global trace clock from lockdep
  ring-buffer: Add set/clear_current_oom_origin() during allocations
  ring-buffer: Check if memory is available before allocation
  lockdep: Add print_irqtrace_events() to __warn
  vsprintf: Do not preprocess non-dereferenced pointers for bprintf (%px and %pK)
  tracing: Uninitialized variable in create_tracing_map_fields()
  tracing: Make sure variable string fields are NULL-terminated
  tracing: Add action comparisons when testing matching hist triggers
  tracing: Don't add flag strings when displaying variable references
  tracing: Fix display of hist trigger expressions containing timestamps
  ftrace: Drop a VLA in module_exists()
  tracing: Mention trace_clock=global when warning about unstable clocks
  tracing: Default to using trace_global_clock if sched_clock is unstable
  ...
2018-04-10 11:27:30 -07:00
David Rientjes 5ecd9d403a mm, page_alloc: wakeup kcompactd even if kswapd cannot free more memory
Kswapd will not wakeup if per-zone watermarks are not failing or if too
many previous attempts at background reclaim have failed.

This can be true if there is a lot of free memory available.  For high-
order allocations, kswapd is responsible for waking up kcompactd for
background compaction.  If the zone is not below its watermarks or
reclaim has recently failed (lots of free memory, nothing left to
reclaim), kcompactd does not get woken up.

When __GFP_DIRECT_RECLAIM is not allowed, allow kcompactd to still be
woken up even if kswapd will not reclaim.  This allows high-order
allocations, such as thp, to still trigger background compaction even
when the zone has an abundance of free memory.

Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1803111659420.209721@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-05 21:36:27 -07:00
Linus Torvalds 680014d6d1 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull time(r) updates from Thomas Gleixner:
 "A small set of updates for timers and timekeeping:

   - The most interesting change is the consolidation of clock MONOTONIC
     and clock BOOTTIME.

     Clock MONOTONIC behaves now exactly like clock BOOTTIME and does
     not longer ignore the time spent in suspend. A new clock
     MONOTONIC_ACTIVE is provived which behaves like clock MONOTONIC in
     kernels before this change. This allows applications to
     programmatically check for the clock MONOTONIC behaviour.

     As discussed in the review thread, this has the potential of
     breaking user space and we might have to revert this. Knock on wood
     that we can avoid that exercise.

   - Updates to the NTP mechanism to improve accuracy

   - A new kernel internal data structure to aid the ongoing Y2038 work.

   - Cleanups and simplifications of the clocksource code.

   - Make the alarmtimer code play nicely with debugobjects"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  alarmtimer: Init nanosleep alarm timer on stack
  y2038: Introduce struct __kernel_old_timeval
  tracing: Unify the "boot" and "mono" tracing clocks
  hrtimer: Unify MONOTONIC and BOOTTIME clock behavior
  posix-timers: Unify MONOTONIC and BOOTTIME clock behavior
  timekeeping: Remove boot time specific code
  Input: Evdev - unify MONOTONIC and BOOTTIME clock behavior
  timekeeping: Make the MONOTONIC clock behave like the BOOTTIME clock
  timekeeping: Add the new CLOCK_MONOTONIC_ACTIVE clock
  timekeeping/ntp: Determine the multiplier directly from NTP tick length
  timekeeping/ntp: Don't align NTP frequency adjustments to ticks
  clocksource: Use ATTRIBUTE_GROUPS
  clocksource: Use DEVICE_ATTR_RW/RO/WO to define device attributes
  clocksource: Don't walk the clocksource list for empty override
2018-04-04 14:50:29 -07:00
Linus Torvalds bb2407a721 There's been a fair amount of activity in Documentation/ this time around:
- Lots of work aligning Documentation/ABI with reality, done by Aishwarya
    Pant.
 
  - The trace documentation has been converted to RST by Changbin Du
 
  - I thrashed up kernel-doc to deal with a parsing issue and to try to make
    the code more readable.  It's still a 20+-year-old Perl hack, though.
 
  - Lots of other updates, typo fixes, and more.
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Merge tag 'docs-4.17' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "There's been a fair amount of activity in Documentation/ this time
  around:

   - Lots of work aligning Documentation/ABI with reality, done by
     Aishwarya Pant.

   - The trace documentation has been converted to RST by Changbin Du

   - I thrashed up kernel-doc to deal with a parsing issue and to try to
     make the code more readable. It's still a 20+-year-old Perl hack,
     though.

   - Lots of other updates, typo fixes, and more"

* tag 'docs-4.17' of git://git.lwn.net/linux: (82 commits)
  Documentation/process: update FUSE project website
  docs: kernel-doc: fix parsing of arrays
  dmaengine: Fix spelling for parenthesis in dmatest documentation
  dmaengine: Make dmatest.rst indeed reST compatible
  dmaengine: Add note to dmatest documentation about supported channels
  Documentation: magic-numbers: Fix typo
  Documentation: admin-guide: add kvmconfig, xenconfig and tinyconfig commands
  Input: alps - Update documentation for trackstick v3 format
  Documentation: Mention why %p prints ptrval
  COPYING: use the new text with points to the license files
  COPYING: create a new file with points to the Kernel license files
  Input: trackpoint: document sysfs interface
  xfs: Change URL for the project in xfs.txt
  char/bsr: add sysfs interface documentation
  acpi: nfit: document sysfs interface
  block: rbd: update sysfs interface
  Documentation/sparse: fix typo
  Documentation/CodingStyle: Add an example for braces
  docs/vm: update 00-INDEX
  kernel-doc: Remove __sched markings
  ...
2018-04-03 13:35:51 -07:00
Thomas Gleixner 92af4dcb4e tracing: Unify the "boot" and "mono" tracing clocks
Unify the "boot" and "mono" tracing clocks and document the new behaviour.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kevin Easton <kevin@guarana.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salyzyn <salyzyn@android.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20180301165150.489635255@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-13 07:34:23 +01:00
Tom Zanussi a4072fe85b tracing: Add a clock attribute for hist triggers
The default clock if timestamps are used in a histogram is "global".
If timestamps aren't used, the clock is irrelevant.

Use the "clock=" param only if you want to override the default
"global" clock for a histogram with timestamps.

Link: http://lkml.kernel.org/r/427bed1389c5d22aa40c3e0683e30cc3d151e260.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Rajvi Jingar <rajvi.jingar@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:06:03 -05:00
Tom Zanussi 033cbceefa tracing: Add inter-event hist trigger Documentation
Add background and details on inter-event hist triggers, including
hist variables, synthetic events, and actions.

Link: http://lkml.kernel.org/r/b0414efb66535aa52aa7411f58c3d56724027fce.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Baohong Liu <baohong.liu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:06:02 -05:00
Tom Zanussi f404da6e1d tracing: Add 'last error' error facility for hist triggers
With the addition of variables and actions, it's become necessary to
provide more detailed error information to users about syntax errors.

Add a 'last error' facility accessible via the erroring event's 'hist'
file.  Reading the hist file after an error will display more detailed
information about what went wrong, if information is available.  This
extended error information will be available until the next hist
trigger command for that event.

  # echo xxx > /sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
  echo: write error: Invalid argument

  # cat /sys/kernel/debug/tracing/events/sched/sched_wakeup/hist

  ERROR: Couldn't yyy: zzz
  Last command: xxx

Also add specific error messages for variable and action errors.

Link: http://lkml.kernel.org/r/64e9c422fc8aeafcc2f7a3b4328c0cffe7969129.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:06:02 -05:00
Tom Zanussi 8b7622bf94 tracing: Add cpu field for hist triggers
A common key to use in a histogram is the cpuid - add a new cpu
'synthetic' field named 'cpu' for that purpose.

Link: http://lkml.kernel.org/r/89537645bfc957e0d76e2cacf5f0ada88691a6cc.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:06:01 -05:00
Tom Zanussi 860f9f6b02 tracing: Add usecs modifier for hist trigger timestamps
Appending .usecs onto a common_timestamp field will cause the
timestamp value to be in microseconds instead of the default
nanoseconds.  A typical latency histogram using usecs would look like
this:

   # echo 'hist:keys=pid,prio:ts0=common_timestamp.usecs ...
   # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0 ...

This also adds an external trace_clock_in_ns() to trace.c for the
timestamp conversion.

Link: http://lkml.kernel.org/r/4e813705a170b3e13e97dc3135047362fb1a39f3.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:54 -05:00
Tom Zanussi 2c1ea60b19 tracing: Add timestamp_mode trace file
Add a new option flag indicating whether or not the ring buffer is in
'absolute timestamp' mode.

Currently this is only set/unset by hist triggers that make use of a
common_timestamp.  As such, there's no reason to make this writeable
for users - its purpose is only to allow users to determine
unequivocally whether or not the ring buffer is in that mode (although
absolute timestamps can coexist with the normal delta timestamps, when
the ring buffer is in absolute mode, timestamps written while absolute
mode is in effect take up more space in the buffer, and are not as
efficient).

Link: http://lkml.kernel.org/r/e8aa7b1cde1cf15014e66545d06ac6ef2ebba456.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:51 -05:00
Tom Zanussi 442c948461 tracing: Add Documentation for log2 modifier
Add a line for the log2 modifier, to keep it aligned with
tracing/README.

Link: http://lkml.kernel.org/r/a419028bccab155749a4b8702d5b97af75f1578f.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:48 -05:00
Tom Zanussi b8df4a3634 tracing: Move hist trigger Documentation to histogram.txt
The hist trigger Documentation takes up a large part of events.txt -
since it will be getting even larger, move it to a separate file.

Link: http://lkml.kernel.org/r/92761155ea4f529e590821b1e02207fe8619f248.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:48 -05:00