Commit Graph

1863 Commits

Author SHA1 Message Date
Steven Rostedt 8ab2b7efd3 ftrace: Remove unnecessary disabling of irqs
The disabling of interrupts around ftrace_update_code() was used
to protect against the evil ftrace daemon from years past. But that
daemon has long been killed. It is safe to keep interrupts enabled
while updating the initial mcount into nops.

The ftrace_mutex is also held which keeps other users at bay.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-04-29 22:52:55 -04:00
Steven Rostedt 0778d9ad33 ftrace: Make FTRACE_WARN_ON() work in if condition
Let FTRACE_WARN_ON() be used as a stand alone statement or
inside a conditional: if (FTRACE_WARN_ON(x))

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-04-29 22:52:52 -04:00
Ingo Molnar 32673822e4 Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core
Conflicts:
	include/linux/perf_event.h

Merge reason: pick up the latest jump-label enhancements, they are cooked ready.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-27 10:40:21 +02:00
Jens Axboe 49cac01e1f block: make unplug timer trace event correspond to the schedule() unplug
It's a pretty close match to what we had before - the timer triggering
would mean that nobody unplugged the plug in due time, in the new
scheme this matches very closely what the schedule() unplug now is.
It's essentially the difference between an explicit unplug (IO unplug)
or an implicit unplug (timer unplug, we scheduled with pending IO
queued).

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-04-16 13:51:05 +02:00
Jens Axboe 94b5eb28b4 block: fixup block IO unplug trace call
It was removed with the on-stack plugging, readd it and track the
depth of requests added when flushing the plug.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-04-12 10:12:19 +02:00
Jens Axboe d9c9783317 block: remove block_unplug_timer() trace point
We no longer have an unplug timer running, so no point in keeping
the trace point.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-04-12 10:06:33 +02:00
Jiri Olsa ee5e51f51b tracing: Avoid soft lockup in trace_pipe
running following commands:

  # enable the binary option
  echo 1 > ./options/bin
  # disable context info option
  echo 0 > ./options/context-info
  # tracing only events
  echo 1 > ./events/enable
  cat trace_pipe

plus forcing system to generate many tracing events,
is causing lockup (in NON preemptive kernels) inside
tracing_read_pipe function.

The issue is also easily reproduced by running ltp stress test.
(ftrace_stress_test.sh)

The reasons are:
 - bin/hex/raw output functions for events are set to
   trace_nop_print function, which prints nothing and
   returns TRACE_TYPE_HANDLED value
 - LOST EVENT trace do not handle trace_seq overflow

These reasons force the while loop in tracing_read_pipe
function never to break.

The attached patch fixies handling of lost event trace, and
changes trace_nop_print to print minimal info, which is needed
for the correct tracing_read_pipe processing.

v2 changes:
 - omit the cond_resched changes by trace_nop_print changes
 - WARN changed to WARN_ONCE and added info to be able
   to find out the culprit

v3 changes:
 - make more accurate patch comment

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
LKML-Reference: <20110325110518.GC1922@jolsa.brq.redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-04-04 12:18:24 -04:00
Steven Rostedt 1813dc3776 tracing: Print trace_bprintk() formats for modules too
The file debugfs/tracing/printk_formats maps the addresses
to the formats that are used by trace_bprintk() so that userspace
tools can read the buffer and be able to decode trace_bprintk events
to get the format saved when reading the ring buffer directly.

This is because trace_bprintk() does not store the format into the
buffer, but just the address of the format, which is hidden in
the kernel memory.

But currently it only exports trace_bprintk()s from the kernel core
and not for modules. The modules need their formats exported
as well.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-04-04 12:18:24 -04:00
Steven Rostedt 0588fa30db tracing: Convert trace_printk() formats for module to const char *
The trace_printk() formats for modules do not show up in the
debugfs/tracing/printk_formats file. Only the formats that are
for trace_printk()s that are in the kernel core.

To facilitate the change to add trace_printk() formats from modules
into that file as well, we need to convert the structure that
holds the formats from char fmt[], into const char *fmt,
and allocate them separately.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-04-04 12:18:24 -04:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Linus Torvalds 2a20b02c05 Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf, x86: Complain louder about BIOSen corrupting CPU/PMU state and continue
  perf, x86: P4 PMU - Read proper MSR register to catch unflagged overflows
  perf symbols: Look at .dynsym again if .symtab not found
  perf build-id: Add quirk to deal with perf.data file format breakage
  perf session: Pass evsel in event_ops->sample()
  perf: Better fit max unprivileged mlock pages for tools needs
  perf_events: Fix stale ->cgrp pointer in update_cgrp_time_from_cpuctx()
  perf top: Fix uninitialized 'counter' variable
  tracing: Fix set_ftrace_filter probe function display
  perf, x86: Fix Intel fixed counters base initialization
2011-03-25 17:53:09 -07:00
Linus Torvalds 6c51038900 Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits)
  Documentation/iostats.txt: bit-size reference etc.
  cfq-iosched: removing unnecessary think time checking
  cfq-iosched: Don't clear queue stats when preempt.
  blk-throttle: Reset group slice when limits are changed
  blk-cgroup: Only give unaccounted_time under debug
  cfq-iosched: Don't set active queue in preempt
  block: fix non-atomic access to genhd inflight structures
  block: attempt to merge with existing requests on plug flush
  block: NULL dereference on error path in __blkdev_get()
  cfq-iosched: Don't update group weights when on service tree
  fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away
  block: Require subsystems to explicitly allocate bio_set integrity mempool
  jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
  jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
  fs: make fsync_buffers_list() plug
  mm: make generic_writepages() use plugging
  blk-cgroup: Add unaccounted time to timeslice_used.
  block: fixup plugging stubs for !CONFIG_BLOCK
  block: remove obsolete comments for blkdev_issue_zeroout.
  blktrace: Use rq->cmd_flags directly in blk_add_trace_rq.
  ...

Fix up conflicts in fs/{aio.c,super.c}
2011-03-24 10:16:26 -07:00
Ingo Molnar e1eb029081 Merge branch 'tip/perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent 2011-03-23 10:35:17 +01:00
Jiri Olsa 1106b6997d tracing: Fix set_ftrace_filter probe function display
If one or more function probes (like traceon) are enabled,
and there's no other function filter, the first probe
func is skipped (which one depends on the position in the hash).

$ echo sys_open:traceon sys_close:traceon > ./set_ftrace_filter
$ cat set_ftrace_filter
#### all functions enabled ####
sys_close:traceon:unlimited
$

The reason was, that in the case of no other function filter,
the func_pos was not properly updated before calling t_hash_start.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
LKML-Reference: <1297874134-7008-1-git-send-email-jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-22 12:52:03 -04:00
Linus Torvalds 619297855a Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (30 commits)
  trace, filters: Initialize the match variable in process_ops() properly
  trace, documentation: Fix branch profiling location in debugfs
  oprofile, s390: Cleanups
  oprofile, s390: Remove hwsampler_files.c and merge it into init.c
  perf: Fix tear-down of inherited group events
  perf: Reorder & optimize perf_event_context to remove alignment padding on 64 bit builds
  perf: Handle stopped state with tracepoints
  perf: Fix the software events state check
  perf, powerpc: Handle events that raise an exception without overflowing
  perf, x86: Use INTEL_*_CONSTRAINT() for all PEBS event constraints
  perf, x86: Clean up SandyBridge PEBS events
  perf lock: Fix sorting by wait_min
  perf tools: Version incorrect with some versions of grep
  perf evlist: New command to list the names of events present in a perf.data file
  perf script: Add support for H/W and S/W events
  perf script: Add support for dumping symbols
  perf script: Support custom field selection for output
  perf script: Move printing of 'common' data from print_event and rename
  perf tracing: Remove print_graph_cpu and print_graph_proc from trace-event-parse
  perf script: Change process_event prototype
  ...
2011-03-18 10:38:34 -07:00
Linus Torvalds e16b396ce3 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (47 commits)
  doc: CONFIG_UNEVICTABLE_LRU doesn't exist anymore
  Update cpuset info & webiste for cgroups
  dcdbas: force SMI to happen when expected
  arch/arm/Kconfig: remove one to many l's in the word.
  asm-generic/user.h: Fix spelling in comment
  drm: fix printk typo 'sracth'
  Remove one to many n's in a word
  Documentation/filesystems/romfs.txt: fixing link to genromfs
  drivers:scsi Change printk typo initate -> initiate
  serial, pch uart: Remove duplicate inclusion of linux/pci.h header
  fs/eventpoll.c: fix spelling
  mm: Fix out-of-date comments which refers non-existent functions
  drm: Fix printk typo 'failled'
  coh901318.c: Change initate to initiate.
  mbox-db5500.c Change initate to initiate.
  edac: correct i82975x error-info reported
  edac: correct i82975x mci initialisation
  edac: correct commented info
  fs: update comments to point correct document
  target: remove duplicate include of target/target_core_device.h from drivers/target/target_core_hba.c
  ...

Trivial conflict in fs/eventpoll.c (spelling vs addition)
2011-03-18 10:37:40 -07:00
Ingo Molnar 1ef1d1c235 trace, filters: Initialize the match variable in process_ops() properly
Make sure the 'match' variable always has a value.

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-18 14:41:27 +01:00
David Rientjes 13e5befadd trace, documentation: Fix branch profiling location in debugfs
The debugfs interface for branch profiling is through

	/sys/kernel/debug/tracing/trace_stat/branch_annotated
	/sys/kernel/debug/tracing/trace_stat/branch_all

so update the Kconfig accordingly.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <alpine.DEB.2.00.1103161716320.11407@chino.kir.corp.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-17 09:10:45 +01:00
Tao Ma 805f6b5e1c blktrace: Use rq->cmd_flags directly in blk_add_trace_rq.
In blk_add_trace_rq, we only chose the minor 2 bits from
request's cmd_flags and did some check for discard.
so most of other flags(e.g, REQ_SYNC) are missing.

For example, with a sync write after blkparse we get:
  8,16   1        1     0.001776503  7509  A  WS 1349632 + 1024 <- (8,17) 1347584
  8,16   1        2     0.001776813  7509  Q  WS 1349632 + 1024 [dd]
  8,16   1        3     0.001780395  7509  G  WS 1349632 + 1024 [dd]
  8,16   1        5     0.001783186  7509  I   W 1349632 + 1024 [dd]
  8,16   1       11     0.001816987  7509  D   W 1349632 + 1024 [dd]
  8,16   0        2     0.006218192     0  C   W 1349632 + 1024 [0]

Since now we have integrated the flags of both bio and request,
it is safe to pass rq->cmd_flags directly to __blk_add_trace.

With this patch, after a sync write we get:
  8,16   1        1     0.001776900  5425  A  WS 1189888 + 1024 <- (8,17) 1187840
  8,16   1        2     0.001777179  5425  Q  WS 1189888 + 1024 [dd]
  8,16   1        3     0.001780797  5425  G  WS 1189888 + 1024 [dd]
  8,16   1        5     0.001783402  5425  I  WS 1189888 + 1024 [dd]
  8,16   1       11     0.001817468  5425  D  WS 1189888 + 1024 [dd]
  8,16   0        2     0.005640709     0  C  WS 1189888 + 1024 [0]

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-11 20:11:59 +01:00
Steven Rostedt 4a0b1665db tracing: Fix irqoff selftest expanding max buffer
If the kernel command line declares a tracer "ftrace=sometracer" and
that tracer is either not defined or is enabled after irqsoff,
then the irqs off selftest will fail with the following error:

Testing tracer irqsoff:
------------[ cut here ]------------
WARNING: at /home/rostedt/work/autotest/nobackup/linux-test.git/kernel/trace/tra
ce.c:713 update_max_tr_single+0xfa/0x11b()
Hardware name:
Modules linked in:
Pid: 1, comm: swapper Not tainted 2.6.38-rc8-test #1
Call Trace:
 [<c0441d9d>] ? warn_slowpath_common+0x65/0x7a
 [<c049adb2>] ? update_max_tr_single+0xfa/0x11b
 [<c0441dc1>] ? warn_slowpath_null+0xf/0x13
 [<c049adb2>] ? update_max_tr_single+0xfa/0x11b
 [<c049e454>] ? stop_critical_timing+0x154/0x204
 [<c049b54b>] ? trace_selftest_startup_irqsoff+0x5b/0xc1
 [<c049b54b>] ? trace_selftest_startup_irqsoff+0x5b/0xc1
 [<c049b54b>] ? trace_selftest_startup_irqsoff+0x5b/0xc1
 [<c049e529>] ? time_hardirqs_on+0x25/0x28
 [<c0468bca>] ? trace_hardirqs_on_caller+0x18/0x12f
 [<c0468cec>] ? trace_hardirqs_on+0xb/0xd
 [<c049b54b>] ? trace_selftest_startup_irqsoff+0x5b/0xc1
 [<c049b6b8>] ? register_tracer+0xf8/0x1a3
 [<c14e93fe>] ? init_irqsoff_tracer+0xd/0x11
 [<c040115e>] ? do_one_initcall+0x71/0x121
 [<c14e93f1>] ? init_irqsoff_tracer+0x0/0x11
 [<c14ce3a9>] ? kernel_init+0x13a/0x1b6
 [<c14ce26f>] ? kernel_init+0x0/0x1b6
 [<c0403842>] ? kernel_thread_helper+0x6/0x10
---[ end trace e93713a9d40cd06c ]---
.. no entries found ..FAILED!

What happens is the "ftrace=..." will expand the ring buffer to its
default size (from its minimum size) but it will not expand the
max ring buffer (the ring buffer to store maximum latencies).
When the irqsoff test runs, it will call the ring buffer swap routine
that checks if the max ring buffer is the same size as the normal
ring buffer, and will fail if it is not. This causes the test to fail.

The solution is to expand the max ring buffer before running the self
test if the max ring buffer is used by that tracer and the normal ring
buffer is expanded. The max ring buffer should be shrunk again after
the test is done to save space.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-10 10:34:58 -05:00
Steven Rostedt 9a24470b28 tracing: Align 4 byte ints together in struct tracer
Move elements in struct tracer for better alignment.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-10 10:34:54 -05:00
Yuanhan Liu 56355b83e2 tracing: Export trace_set_clr_event()
Trace events belonging to a module only exists when the module is
loaded. Well, we can use trace_set_clr_event funtion to enable some
trace event at the module init routine, so that we will not miss
something while loading then module.

So, Export the trace_set_clr_event function so that module can use it.

Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
LKML-Reference: <1289196312-25323-1-git-send-email-yuanhan.liu@linux.intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-10 10:34:51 -05:00
Jiri Olsa 31274d72f0 tracing: Explain about unstable clock on resume with ring buffer warning
The "Delta way too big" warning might appear on a system with a
unstable shed clock right after the system is resumed and tracing
was enabled at time of suspend.

Since it's not realy a bug, and the unstable sched clock is working
fast and reliable otherwise, Steven suggested to keep using the
sched clock in any case and just to make note in the warning itself.

v2 changes:
- added #ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
LKML-Reference: <20110218145219.GD2604@jolsa.brq.redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-10 10:34:47 -05:00
David Sharp 10da37a645 tracing: Adjust conditional expression latency formatting.
Formatting change only to improve code readability. No code changes except to
introduce intermediate variables.

Signed-off-by: David Sharp <dhsharp@google.com>
LKML-Reference: <1291421609-14665-13-git-send-email-dhsharp@google.com>

[ Keep variable declarations and assignment separate ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-10 10:34:35 -05:00
David Sharp 140e4f2d1c tracing: Fix event alignment: ftrace:context_switch and ftrace:wakeup
Signed-off-by: David Sharp <dhsharp@google.com>
LKML-Reference: <1291421609-14665-6-git-send-email-dhsharp@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-10 10:34:16 -05:00
Steven Rostedt e6e1e25935 tracing: Remove lock_depth from event entry
The lock_depth field in the event headers was added as a temporary
data point for help in removing the BKL. Now that the BKL is pretty
much been removed, we can remove this field.

This in turn changes the header from 12 bytes to 8 bytes,
removing the 4 byte buffer that gcc would insert if the first field
in the data load was 8 bytes in size.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-10 10:31:48 -05:00
David Sharp de29be5e71 ring-buffer: Remove unused #include <linux/trace_irq.h>
Signed-off-by: David Sharp <dhsharp@google.com>
LKML-Reference: <1291421609-14665-3-git-send-email-dhsharp@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-09 13:52:28 -05:00
David Sharp 750912fa36 tracing: Add an 'overwrite' trace_option.
Add an "overwrite" trace_option for ftrace to control whether the buffer should
be overwritten on overflow or not. The default remains to overwrite old events
when the buffer is full. This patch adds the option to instead discard newest
events when the buffer is full. This is useful to get a snapshot of traces just
after enabling traces. Dropping the current event is also a simpler code path.

Signed-off-by: David Sharp <dhsharp@google.com>
LKML-Reference: <1291844807-15481-1-git-send-email-dhsharp@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-09 13:52:27 -05:00
Ingo Molnar 86cb2ec7b2 Merge commit 'v2.6.38-rc8' into perf/core
Merge reason: Merge latest fixes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-08 17:21:52 +01:00
Tao Ma 2d3a8497f8 blktrace: Remove blk_fill_rwbs_rq.
If we enable trace events to trace block actions, We use
blk_fill_rwbs_rq to analyze the corresponding actions
in request's cmd_flags, but we only choose the minor 2 bits
from it, so most of other flags(e.g, REQ_SYNC) are missing.
For example, with a sync write we get:
write_test-2409  [001]   160.013869: block_rq_insert: 3,64 W 0 () 258135 + =
8 [write_test]

Since now we have integrated the flags of both bio and request,
it is safe to pass rq->cmd_flags directly to blk_fill_rwbs and
blk_fill_rwbs_rq isn't needed any more.

With this patch, after a sync write we get:
write_test-2417  [000]   226.603878: block_rq_insert: 3,64 WS 0 () 258135 +=
 8 [write_test]

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-03 10:53:20 -05:00
Frederic Weisbecker c09d7a3d2e Merge branch '/tip/perf/filter' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git into perf/core 2011-03-03 04:29:25 +01:00
Ingo Molnar e9345aab67 Revert "tracing: Add unstable sched clock note to the warning"
This reverts commit 5e38ca8f3e.

Breaks the build of several !CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
architectures.

Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Message-ID: <20110217171823.GB17058@elte.hu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-18 08:09:49 +01:00
Ingo Molnar 5beda5f6e4 Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core 2011-02-17 14:11:15 +01:00
Ingo Molnar b00560f2d4 Merge branch 'perf/urgent' into perf/core
Merge reason: we need to queue up dependent patch

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-16 13:27:23 +01:00
Jiri Kosina 0a9d59a246 Merge branch 'master' into for-next 2011-02-15 10:24:31 +01:00
Ingo Molnar bf1af3a809 Merge branch 'tip/perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core 2011-02-14 15:15:16 +01:00
Masami Hiramatsu 0de4b34d46 tracing/kprobe: Fix NULL pointer deref check
Add NULL check for avoiding NULL pointer deref.
This bug has been introduced by:

  1ff511e35ed8: tracing/kprobes: Add bitfield type

which causes a null pointer dereference bug when kprobe-tracer
parses an argument without type.

Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: 2nddept-manager@sdl.hitachi.co.jp
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20110214054807.8919.69740.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reported-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
2011-02-14 12:09:53 +01:00
Steven Rostedt 868baf07b1 ftrace: Fix memory leak with function graph and cpu hotplug
When the fuction graph tracer starts, it needs to make a special
stack for each task to save the real return values of the tasks.
All running tasks have this stack created, as well as any new
tasks.

On CPU hot plug, the new idle task will allocate a stack as well
when init_idle() is called. The problem is that cpu hotplug does
not create a new idle_task. Instead it uses the idle task that
existed when the cpu went down.

ftrace_graph_init_task() will add a new ret_stack to the task
that is given to it. Because a clone will make the task
have a stack of its parent it does not check if the task's
ret_stack is already NULL or not. When the CPU hotplug code
starts a CPU up again, it will allocate a new stack even
though one already existed for it.

The solution is to treat the idle_task specially. In fact, the
function_graph code already does, just not at init_idle().
Instead of using the ftrace_graph_init_task() for the idle task,
which that function expects the task to be a clone, have a
separate ftrace_graph_init_idle_task(). Also, we will create a
per_cpu ret_stack that is used by the idle task. When we call
ftrace_graph_init_idle_task() it will check if the idle task's
ret_stack is NULL, if it is, then it will assign it the per_cpu
ret_stack.

Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-11 16:23:33 -05:00
Linus Torvalds aceb91cd35 Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  cdrom: support devices that have check_events but not media_changed
  cfq-iosched: Don't wait if queue already has requests.
  blkio-throttle: Avoid calling blkiocg_lookup_group() for root group
  cfq: rename a function to give it more appropriate name
  cciss: make cciss_revalidate not loop through CISS_MAX_LUNS volumes unnecessarily.
  drivers/block/aoe/Makefile: replace the use of <module>-objs with <module>-y
  loop: queue_lock NULL pointer derefence in blk_throtl_exit
  drivers/block/Makefile: replace the use of <module>-objs with <module>-y
  blktrace: Don't output messages if NOTIFY isn't set.
2011-02-09 11:45:21 -08:00
Steven Rostedt 6752ab4a9c tracing: Deprecate tracing_enabled for tracing_on
tracing_enabled should not be used, it is heavy weight and does not
do much in helping lower the overhead.

tracing_on should be used instead. Warn users to use tracing_on
when tracing_enabled is used as it will soon be removed from the
tracing directory.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-08 17:14:58 -05:00
Steven Rostedt 87d80de280 tracing: Remove obsolete sched_switch tracer
The trace events sched_switch and sched_wakeup do the same thing
as the stand alone sched_switch tracer does. It is no longer needed.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-08 17:14:56 -05:00
Jiri Olsa 5e38ca8f3e tracing: Add unstable sched clock note to the warning
The warning "Delta way too big" warning might appear on a system with
unstable shed clock right after the system is resumed and tracing
was enabled during the suspend.

Since it's not realy bug, and the unstable sched clock is working
fast and reliable otherwise, Steven suggested to keep using the
sched clock in any case and just to make note in the warning itself.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
LKML-Reference: <1296649698-6003-1-git-send-email-jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-08 11:57:22 -05:00
Ian Munsie ae07f551c4 tracing/syscalls: Early terminate search for sys_ni_syscall
Many system calls are unimplemented and mapped to sys_ni_syscall, but at
boot ftrace would still search through every syscall metadata entry for
a match which wouldn't be there.

This patch adds causes the search to terminate early if the system call
is not mapped.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
LKML-Reference: <1296703645-18718-7-git-send-email-imunsie@au1.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 21:30:14 -05:00
Ian Munsie b2d5549681 tracing/syscalls: Allow arch specific syscall symbol matching
Some architectures have unusual symbol names and the generic code to
match the symbol name with the function name for the syscall metadata
will fail. For example, symbols on PPC64 start with a period and the
generic code will fail to match them.

This patch moves the match logic out into a separate function which an
arch can override by defining ARCH_HAS_SYSCALL_MATCH_SYM_NAME in
asm/ftrace.h and implementing arch_syscall_match_sym_name.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
LKML-Reference: <1296703645-18718-5-git-send-email-imunsie@au1.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 21:29:03 -05:00
Ian Munsie c763ba06bd tracing/syscalls: Make arch_syscall_addr weak
Some architectures use non-trivial system call tables and will not work
with the generic arch_syscall_addr code. For example, PowerPC64 uses a
table of twin long longs.

This patch makes the generic arch_syscall_addr weak to allow
architectures with non-trivial system call tables to override it.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
LKML-Reference: <1296703645-18718-4-git-send-email-imunsie@au1.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 21:26:22 -05:00
Ian Munsie 3773b389b6 tracing/syscalls: Convert redundant syscall_nr checks into WARN_ON
With the ftrace events now checking if the syscall_nr is valid upon
initialisation it should no longer be possible to register or unregister
a syscall event without a valid syscall_nr since they should not be
created. This adds a WARN_ON_ONCE in the register and unregister
functions to locate potential regressions in the future.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
LKML-Reference: <1296703645-18718-3-git-send-email-imunsie@au1.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 21:25:52 -05:00
Ian Munsie ba976970c7 tracing/syscalls: Don't add events for unmapped syscalls
FTRACE_SYSCALLS would create events for each and every system call, even
if it had failed to map the system call's name with it's number. This
resulted in a number of events being created that would not behave as
expected.

This could happen, for example, on architectures who's symbol names are
unusual and will not match the system call name. It could also happen
with system calls which were mapped to sys_ni_syscall.

This patch changes the default system call number in the metadata to -1.
If the system call name from the metadata is not successfully mapped to
a system call number during boot, than the event initialisation routine
will now return an error, preventing the event from being created.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
LKML-Reference: <1296703645-18718-2-git-send-email-imunsie@au1.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 21:24:44 -05:00
Steven Rostedt 4defe682d8 tracing/filter: Remove synchronize_sched() from __alloc_preds()
Because the filters are processed first and then activated
(added to the call), we no longer need to worry about the preds
of the filter in __alloc_preds() being used. As the filter that
is allocating preds is not activated yet.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 20:56:20 -05:00
Steven Rostedt 75b8e98263 tracing/filter: Swap entire filter of events
When creating a new filter, instead of allocating the filter to the
event call first and then processing the filter, it is easier to
process a temporary filter and then just swap it with the call filter.
By doing this, it simplifies the code.

A filter is allocated and processed, when it is done, it is
swapped with the call filter, synchronize_sched() is called to make
sure all callers are done with the old filter (filters are called
with premption disabled), and then the old filter is freed.

Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 20:56:20 -05:00
Steven Rostedt bf93f9ed3a tracing/filter: Increase the max preds to 2^14
Now that the filter logic does not require to save the pred results
on the stack, we can increase the max number of preds we allow.
As the preds are index by a short value, and we use the MSBs as flags
we can increase the max preds to 2^14 (16384) which should be way
more than enough.

Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 20:56:20 -05:00