Currently, tracing_thresh works only if we specify it before selecting
function_graph tracer. If we do the opposite, tracing_thresh will change
it's value, but it will not be applied.
To fix it, we add update_thresh callback which is called whenever
tracing_thresh is updated and for function_graph tracer we register
handler which reinitializes tracer depending on tracing_thresh.
Link: http://lkml.kernel.org/p/20140718111727.GA3206@stfomichev-desktop.yandex.net
Signed-off-by: Stanislav Fomichev <stfomichev@yandex-team.ru>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The check that tests if ftrace_trace_arrays is empty in
top_trace_array(), uses the .prev pointer:
if (list_empty(ftrace_trace_arrays.prev))
instead of testing the variable itself:
if (list_empty(&ftrace_trace_arrays))
Although it is technically correct, it is awkward and confusing.
Use the proper method.
Link: http://lkml.kernel.org/r/87oay1bas8.fsf@sejong.aot.lge.com
Reported-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
ftrace_trace_arrays links global_trace.list. However, global_trace
is not added to ftrace_trace_arrays if trace_alloc_buffers() failed.
As the result, ftrace_trace_arrays becomes an empty list. If
ftrace_trace_arrays is an empty list, current top_trace_array() returns
an invalid pointer. As the result, the kernel can induce memory corruption
or panic.
Current implementation does not check whether ftrace_trace_arrays is empty
list or not. So, in this patch, if ftrace_trace_arrays is empty list,
top_trace_array() returns NULL. Moreover, this patch makes all functions
calling top_trace_array() handle it appropriately.
Link: http://lkml.kernel.org/p/20140605223517.32311.99233.stgit@yunodevel
Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In the function-graph tracer, add a funcgraph_tail option
to print the function name on all } lines, not just
functions whose first line is no longer in the trace
buffer.
If a function calls other traced functions, its total
time appears on its } line. This change allows grep
to be used to determine the function for which the
line corresponds.
Update Documentation/trace/ftrace.txt to describe
this new option.
Link: http://lkml.kernel.org/p/20140520221041.8359.6782.stgit@beardog.cce.hp.com
Signed-off-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Eliminate duplicate TRACE_GRAPH_PRINT_xx defines
in trace_functions_graph.c that are already in
trace.h.
Add TRACE_GRAPH_PRINT_IRQS to trace.h, which is
the only one that is missing.
Link: http://lkml.kernel.org/p/20140520221031.8359.24733.stgit@beardog.cce.hp.com
Signed-off-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Now that the ring buffer has a built in way to wake up readers
when there's data, using irq_work such that it is safe to do it
in any context. But it was still using the old "poor man's"
wait polling that checks every 1/10 of a second to see if it
should wake up a waiter. This makes the latency for a wake up
excruciatingly long. No need to do that anymore.
Completely remove the different wait_poll types from the tracers
and have them all use the default one now.
Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When using ftrace_ops_list_func, we should skip 4 instead of 3,
to avoid ftrace_call+0x5/0xb appearing in the stack trace:
Depth Size Location (110 entries)
----- ---- --------
0) 2956 0 update_curr+0xe/0x1e0
1) 2956 68 ftrace_call+0x5/0xb
2) 2888 92 enqueue_entity+0x53/0xe80
3) 2796 80 enqueue_task_fair+0x47/0x7e0
4) 2716 28 enqueue_task+0x45/0x70
5) 2688 12 activate_task+0x22/0x30
Add a function using_ftrace_ops_list_func() to test for this while keeping
ftrace_ops_list_func to remain static.
Link: http://lkml.kernel.org/p/1398006644-5935-2-git-send-email-wangjiaxing@insigma.com.cn
Signed-off-by: Jiaxing Wang <wangjiaxing@insigma.com.cn>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In preparation for having tracers enabled in instances, the max_lock
should be unique as updating the max for one tracer is a separate
operation than updating it for another tracer using a different max.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In preparation for letting the latency tracers be used by instances,
remove the global tracing_max_latency variable and add a max_latency
field to the trace_array that the latency tracers will now use.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Instead of having a list of global functions that are called,
as only one global function is allow to be enabled at a time, there's
no reason to have a list.
Instead, simply have all the users of the global ops, use the global ops
directly, instead of registering their own ftrace_ops. Just switch what
function is used before enabling the function tracer.
This removes a lot of code as well as the complexity involved with it.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
To increase compiler portability there is <linux/compiler.h> which
provides convenience macros for various gcc constructs. Eg: __weak for
__attribute__((weak)). I've replaced all instances of gcc attributes
with the right macro in the kernel subsystem.
Signed-off-by: Gideon Israel Dsouza <gidisrael@gmail.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Create a "set_ftrace_filter" and "set_ftrace_notrace" files in the instance
directories to let users filter of functions to trace for the given instance.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Allow instances (sub-buffers) to enable function tracing.
Each instance will have its own function tracing capability.
For now, instances will not have function stack tracing, or will
they be able to pick and choose what functions they can trace.
Picking and choosing their own functions will come later.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
As tracers will soon be used by instances, the tracer enabled field
needs to be converted to a counter instead of a boolean.
This counter is protected by the trace_types_lock mutex.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently the tracers (function, function_graph, irqsoff, etc) can only
be used by the top level tracing directory (not for instances).
This sets up the infrastructure to allow instances to be able to
run a separate tracer apart from the what the top level tracing is
doing.
As tracers need to adapt for being used by instances, the tracers
must flag if they can be used by instances or not. Currently only the
'nop' tracer can be used by all instances.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
As options (flags) may affect instances instead of being global
the flag_changed() callbacks need to receive the trace_array descriptor
of the instance they will be modifying.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
As options (flags) may affect instances instead of being global
the set_flag() callbacks need to receive the trace_array descriptor
of the instance they will be modifying.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The filter field of the event_trigger_data structure is protected under
RCU sched locks. It was not annotated as such, and after doing so,
sparse pointed out several locations that required fix ups.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Trace event triggers added a lseek that uses the ftrace_filter_lseek()
function. Unfortunately, when function tracing is not configured in
that function is not defined and the kernel fails to build.
This is the second time that function was added to a file ops and
it broke the build due to requiring special config dependencies.
Make a generic tracing_lseek() that all the tracing utilities may
use.
Also, modify the old ftrace_filter_lseek() to return 0 instead of
1 on WRONLY. Not sure why it was a 1 as that does not make sense.
This also changes the old tracing_seek() to modify the file pos
pointer on WRONLY as well.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add a generic event_command.set_trigger_filter() op implementation and
have the current set of trigger commands use it - this essentially
gives them all support for filters.
Syntactically, filters are supported by adding 'if <filter>' just
after the command, in which case only events matching the filter will
invoke the trigger. For example, to add a filter to an
enable/disable_event command:
echo 'enable_event:system:event if common_pid == 999' > \
.../othersys/otherevent/trigger
The above command will only enable the system:event event if the
common_pid field in the othersys:otherevent event is 999.
As another example, to add a filter to a stacktrace command:
echo 'stacktrace if common_pid == 999' > \
.../somesys/someevent/trigger
The above command will only trigger a stacktrace if the common_pid
field in the event is 999.
The filter syntax is the same as that described in the 'Event
filtering' section of Documentation/trace/events.txt.
Because triggers can now use filters, the trigger-invoking logic needs
to be moved in those cases - e.g. for ftrace_raw_event_calls, if a
trigger has a filter associated with it, the trigger invocation now
needs to happen after the { assign; } part of the call, in order for
the trigger condition to be tested.
There's still a SOFT_DISABLED-only check at the top of e.g. the
ftrace_raw_events function, so when an event is soft disabled but not
because of the presence of a trigger, the original SOFT_DISABLED
behavior remains unchanged.
There's also a bit of trickiness in that some triggers need to avoid
being invoked while an event is currently in the process of being
logged, since the trigger may itself log data into the trace buffer.
Thus we make sure the current event is committed before invoking those
triggers. To do that, we split the trigger invocation in two - the
first part (event_triggers_call()) checks the filter using the current
trace record; if a command has the post_trigger flag set, it sets a
bit for itself in the return value, otherwise it directly invoks the
trigger. Once all commands have been either invoked or set their
return flag, event_triggers_call() returns. The current record is
then either committed or discarded; if any commands have deferred
their triggers, those commands are finally invoked following the close
of the current event by event_triggers_post_call().
To simplify the above and make it more efficient, the TRIGGER_COND bit
is introduced, which is set only if a soft-disabled trigger needs to
use the log record for filter testing or needs to wait until the
current log record is closed.
The syscall event invocation code is also changed in analogous ways.
Because event triggers need to be able to create and free filters,
this also adds a couple external wrappers for the existing
create_filter and free_filter functions, which are too generic to be
made extern functions themselves.
Link: http://lkml.kernel.org/r/7164930759d8719ef460357f143d995406e4eead.1382622043.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add 'enable_event' and 'disable_event' event_command commands.
enable_event and disable_event event triggers are added by the user
via these commands in a similar way and using practically the same
syntax as the analagous 'enable_event' and 'disable_event' ftrace
function commands, but instead of writing to the set_ftrace_filter
file, the enable_event and disable_event triggers are written to the
per-event 'trigger' files:
echo 'enable_event:system:event' > .../othersys/otherevent/trigger
echo 'disable_event:system:event' > .../othersys/otherevent/trigger
The above commands will enable or disable the 'system:event' trace
events whenever the othersys:otherevent events are hit.
This also adds a 'count' version that limits the number of times the
command will be invoked:
echo 'enable_event:system:event:N' > .../othersys/otherevent/trigger
echo 'disable_event:system:event:N' > .../othersys/otherevent/trigger
Where N is the number of times the command will be invoked.
The above commands will will enable or disable the 'system:event'
trace events whenever the othersys:otherevent events are hit, but only
N times.
This also makes the find_event_file() helper function extern, since
it's useful to use from other places, such as the event triggers code,
so make it accessible.
Link: http://lkml.kernel.org/r/f825f3048c3f6b026ee37ae5825f9fc373451828.1382622043.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add 'snapshot' event_command. snapshot event triggers are added by
the user via this command in a similar way and using practically the
same syntax as the analogous 'snapshot' ftrace function command, but
instead of writing to the set_ftrace_filter file, the snapshot event
trigger is written to the per-event 'trigger' files:
echo 'snapshot' > .../somesys/someevent/trigger
The above command will turn on snapshots for someevent i.e. whenever
someevent is hit, a snapshot will be done.
This also adds a 'count' version that limits the number of times the
command will be invoked:
echo 'snapshot:N' > .../somesys/someevent/trigger
Where N is the number of times the command will be invoked.
The above command will snapshot N times for someevent i.e. whenever
someevent is hit N times, a snapshot will be done.
Also adds a new tracing_alloc_snapshot() function - the existing
tracing_snapshot_alloc() function is a special version of
tracing_snapshot() that also does the snapshot allocation - the
snapshot triggers would like to be able to do just the allocation but
not take a snapshot; the existing tracing_snapshot_alloc() in turn now
also calls tracing_alloc_snapshot() underneath to do that allocation.
Link: http://lkml.kernel.org/r/c9524dd07ce01f9dcbd59011290e0a8d5b47d7ad.1382622043.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[ fix up from kbuild test robot <fengguang.wu@intel.com report ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add a 'trigger' file for each trace event, enabling 'trace event
triggers' to be set for trace events.
'trace event triggers' are patterned after the existing 'ftrace
function triggers' implementation except that triggers are written to
per-event 'trigger' files instead of to a single file such as the
'set_ftrace_filter' used for ftrace function triggers.
The implementation is meant to be entirely separate from ftrace
function triggers, in order to keep the respective implementations
relatively simple and to allow them to diverge.
The event trigger functionality is built on top of SOFT_DISABLE
functionality. It adds a TRIGGER_MODE bit to the ftrace_event_file
flags which is checked when any trace event fires. Triggers set for a
particular event need to be checked regardless of whether that event
is actually enabled or not - getting an event to fire even if it's not
enabled is what's already implemented by SOFT_DISABLE mode, so trigger
mode directly reuses that. Event trigger essentially inherit the soft
disable logic in __ftrace_event_enable_disable() while adding a bit of
logic and trigger reference counting via tm_ref on top of that in a
new trace_event_trigger_enable_disable() function. Because the base
__ftrace_event_enable_disable() code now needs to be invoked from
outside trace_events.c, a wrapper is also added for those usages.
The triggers for an event are actually invoked via a new function,
event_triggers_call(), and code is also added to invoke them for
ftrace_raw_event calls as well as syscall events.
The main part of the patch creates a new trace_events_trigger.c file
to contain the trace event triggers implementation.
The standard open, read, and release file operations are implemented
here.
The open() implementation sets up for the various open modes of the
'trigger' file. It creates and attaches the trigger iterator and sets
up the command parser. If opened for reading set up the trigger
seq_ops.
The read() implementation parses the event trigger written to the
'trigger' file, looks up the trigger command, and passes it along to
that event_command's func() implementation for command-specific
processing.
The release() implementation does whatever cleanup is needed to
release the 'trigger' file, like releasing the parser and trigger
iterator, etc.
A couple of functions for event command registration and
unregistration are added, along with a list to add them to and a mutex
to protect them, as well as an (initially empty) registration function
to add the set of commands that will be added by future commits, and
call to it from the trace event initialization code.
also added are a couple trigger-specific data structures needed for
these implementations such as a trigger iterator and a struct for
trigger-specific data.
A couple structs consisting mostly of function meant to be implemented
in command-specific ways, event_command and event_trigger_ops, are
used by the generic event trigger command implementations. They're
being put into trace.h alongside the other trace_event data structures
and functions, in the expectation that they'll be needed in several
trace_event-related files such as trace_events_trigger.c and
trace_events.c.
The event_command.func() function is meant to be called by the trigger
parsing code in order to add a trigger instance to the corresponding
event. It essentially coordinates adding a live trigger instance to
the event, and arming the triggering the event.
Every event_command func() implementation essentially does the
same thing for any command:
- choose ops - use the value of param to choose either a number or
count version of event_trigger_ops specific to the command
- do the register or unregister of those ops
- associate a filter, if specified, with the triggering event
The reg() and unreg() ops allow command-specific implementations for
event_trigger_op registration and unregistration, and the
get_trigger_ops() op allows command-specific event_trigger_ops
selection to be parameterized. When a trigger instance is added, the
reg() op essentially adds that trigger to the triggering event and
arms it, while unreg() does the opposite. The set_filter() function
is used to associate a filter with the trigger - if the command
doesn't specify a set_filter() implementation, the command will ignore
filters.
Each command has an associated trigger_type, which serves double duty,
both as a unique identifier for the command as well as a value that
can be used for setting a trigger mode bit during trigger invocation.
The signature of func() adds a pointer to the event_command struct,
used to invoke those functions, along with a command_data param that
can be passed to the reg/unreg functions. This allows func()
implementations to use command-specific blobs and supports code
re-use.
The event_trigger_ops.func() command corrsponds to the trigger 'probe'
function that gets called when the triggering event is actually
invoked. The other functions are used to list the trigger when
needed, along with a couple mundane book-keeping functions.
This also moves event_file_data() into trace.h so it can be used
outside of trace_events.c.
Link: http://lkml.kernel.org/r/316d95061accdee070aac8e5750afba0192fa5b9.1382622043.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Idea-by: Steve Rostedt <rostedt@goodmis.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The only real feature that was added this release is from Namhyung Kim,
who introduced "set_graph_notrace" filter that lets you run the function
graph tracer and not trace particular functions and their call chain.
Tom Zanussi added some updates to the ftrace multibuffer tracing that
made it more consistent with the top level tracing.
One of the fixes for perf function tracing required an API change in
RCU; the addition of "rcu_is_watching()". As Paul McKenney is pushing
that change in this release too, he gave me a branch that included
all the changes to get that working, and I pulled that into my tree
in order to complete the perf function tracing fix.
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Merge tag 'trace-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing update from Steven Rostedt:
"This batch of changes is mostly clean ups and small bug fixes. The
only real feature that was added this release is from Namhyung Kim,
who introduced "set_graph_notrace" filter that lets you run the
function graph tracer and not trace particular functions and their
call chain.
Tom Zanussi added some updates to the ftrace multibuffer tracing that
made it more consistent with the top level tracing.
One of the fixes for perf function tracing required an API change in
RCU; the addition of "rcu_is_watching()". As Paul McKenney is pushing
that change in this release too, he gave me a branch that included all
the changes to get that working, and I pulled that into my tree in
order to complete the perf function tracing fix"
* tag 'trace-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Add rcu annotation for syscall trace descriptors
tracing: Do not use signed enums with unsigned long long in fgragh output
tracing: Remove unused function ftrace_off_permanent()
tracing: Do not assign filp->private_data to freed memory
tracing: Add helper function tracing_is_disabled()
tracing: Open tracer when ftrace_dump_on_oops is used
tracing: Add support for SOFT_DISABLE to syscall events
tracing: Make register/unregister_ftrace_command __init
tracing: Update event filters for multibuffer
recordmcount.pl: Add support for __fentry__
ftrace: Have control op function callback only trace when RCU is watching
rcu: Do not trace rcu_is_watching() functions
ftrace/x86: skip over the breakpoint for ftrace caller
trace/trace_stat: use rbtree postorder iteration helper instead of opencoding
ftrace: Add set_graph_notrace filter
ftrace: Narrow down the protected area of graph_lock
ftrace: Introduce struct ftrace_graph_data
ftrace: Get rid of ftrace_graph_filter_enabled
tracing: Fix potential out-of-bounds in trace_get_user()
tracing: Show more exact help information about snapshot
sparse complains about the enter/exit_sysycall_files[] variables being
dereferenced with rcu_dereference_sched(). The fields need to be
annotated with __rcu.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Since the introduction of PREEMPT_NEED_RESCHED in:
f27dde8dee ("sched: Add NEED_RESCHED to the preempt_count")
we need to be able to look at both TIF_NEED_RESCHED and
PREEMPT_NEED_RESCHED to understand the full preemption behaviour.
Add it to the trace output.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Link: http://lkml.kernel.org/r/20131004152826.GP3081@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The duration field of print_graph_duration() can also be used
to do the space filling by passing an enum in it:
DURATION_FILL_FULL
DURATION_FILL_START
DURATION_FILL_END
The problem is that these are enums and defined as negative,
but the duration field is unsigned long long. Most archs are
fine with this but blackfin fails to compile because of it:
kernel/built-in.o: In function `print_graph_duration':
kernel/trace/trace_functions_graph.c:782: undefined reference to `__ucmpdi2'
Overloading a unsigned long long with an signed enum is just
bad in principle. We can accomplish the same thing by using
part of the flags field instead.
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The original SOFT_DISABLE patches didn't add support for soft disable
of syscall events; this adds it.
Add an array of ftrace_event_file pointers indexed by syscall number
to the trace array and remove the existing enabled bitmaps, which as a
result are now redundant. The ftrace_event_file structs in turn
contain the soft disable flags we need for per-syscall soft disable
accounting.
Adding ftrace_event_files also means we can remove the USE_CALL_FILTER
bit, thus enabling multibuffer filter support for syscall events.
Link: http://lkml.kernel.org/r/6e72b566e85d8df8042f133efbc6c30e21fb017e.1382620672.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The trace event filters are still tied to event calls rather than
event files, which means you don't get what you'd expect when using
filters in the multibuffer case:
Before:
# echo 'bytes_alloc > 8192' > /sys/kernel/debug/tracing/events/kmem/kmalloc/filter
# cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter
bytes_alloc > 8192
# mkdir /sys/kernel/debug/tracing/instances/test1
# echo 'bytes_alloc > 2048' > /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter
# cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter
bytes_alloc > 2048
# cat /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter
bytes_alloc > 2048
Setting the filter in tracing/instances/test1/events shouldn't affect
the same event in tracing/events as it does above.
After:
# echo 'bytes_alloc > 8192' > /sys/kernel/debug/tracing/events/kmem/kmalloc/filter
# cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter
bytes_alloc > 8192
# mkdir /sys/kernel/debug/tracing/instances/test1
# echo 'bytes_alloc > 2048' > /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter
# cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter
bytes_alloc > 8192
# cat /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter
bytes_alloc > 2048
We'd like to just move the filter directly from ftrace_event_call to
ftrace_event_file, but there are a couple cases that don't yet have
multibuffer support and therefore have to continue using the current
event_call-based filters. For those cases, a new USE_CALL_FILTER bit
is added to the event_call flags, whose main purpose is to keep the
old behavior for those cases until they can be updated with
multibuffer support; at that point, the USE_CALL_FILTER flag (and the
new associated call_filter_check_discard() function) can go away.
The multibuffer support also made filter_current_check_discard()
redundant, so this change removes that function as well and replaces
it with filter_check_discard() (or call_filter_check_discard() as
appropriate).
Link: http://lkml.kernel.org/r/f16e9ce4270c62f46b2e966119225e1c3cca7e60.1382620672.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The ftrace_graph_filter_enabled means that user sets function filter
and it always has same meaning of ftrace_graph_count > 0.
Link: http://lkml.kernel.org/r/1381739066-7531-2-git-send-email-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
are still in flux, and will have to wait for 3.13.
The changes for 3.12 are mostly clean ups and minor fixes.
H. Peter Anvin added a check to x86_32 static function tracing that
helps a small segment of the kernel community.
Oleg Nesterov had a few changes from 3.11, but were mostly clean ups
and not worth pushing in the -rc time frame.
Li Zefan had small clean up with annotating a raw_init with __init.
I fixed a slight race in updating function callbacks, but the race
is so small and the bug that happens when it occurs is so minor it's
not even worth pushing to stable.
The only real enhancement is from Alexander Z Lam that made the
tracing_cpumask work for trace buffer instances, instead of them all
sharing a global cpumask.
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Merge tag 'trace-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"Not much changes for the 3.12 merge window. The major tracing changes
are still in flux, and will have to wait for 3.13.
The changes for 3.12 are mostly clean ups and minor fixes.
H Peter Anvin added a check to x86_32 static function tracing that
helps a small segment of the kernel community.
Oleg Nesterov had a few changes from 3.11, but were mostly clean ups
and not worth pushing in the -rc time frame.
Li Zefan had small clean up with annotating a raw_init with __init.
I fixed a slight race in updating function callbacks, but the race is
so small and the bug that happens when it occurs is so minor it's not
even worth pushing to stable.
The only real enhancement is from Alexander Z Lam that made the
tracing_cpumask work for trace buffer instances, instead of them all
sharing a global cpumask"
* tag 'trace-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace/rcu: Do not trace debug_lockdep_rcu_enabled()
x86-32, ftrace: Fix static ftrace when early microcode is enabled
ftrace: Fix a slight race in modifying what function callback gets traced
tracing: Make tracing_cpumask available for all instances
tracing: Kill the !CONFIG_MODULES code in trace_events.c
tracing: Don't pass file_operations array to event_create_dir()
tracing: Kill trace_create_file_ops() and friends
tracing/syscalls: Annotate raw_init function with __init
Pull RCU updates from Paul E. McKenney:
"
* Update RCU documentation. These were posted to LKML at
https://lkml.org/lkml/2013/8/19/611.
* Miscellaneous fixes. These were posted to LKML at
https://lkml.org/lkml/2013/8/19/619.
* Full-system idle detection. This is for use by Frederic
Weisbecker's adaptive-ticks mechanism. Its purpose is
to allow the timekeeping CPU to shut off its tick when
all other CPUs are idle. These were posted to LKML at
https://lkml.org/lkml/2013/8/19/648.
* Improve rcutorture test coverage. These were posted to LKML at
https://lkml.org/lkml/2013/8/19/675.
"
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Allow tracer instances to disable tracing by cpu by moving
the static global tracing_cpumask into trace_array.
Link: http://lkml.kernel.org/r/921622317f239bfc2283cac2242647801ef584f2.1375980149.git.azl@google.com
Cc: Vaibhav Nagarnaik <vnagarnaik@google.com>
Cc: David Sharp <dhsharp@google.com>
Cc: Alexander Z Lam <lambchop468@gmail.com>
Signed-off-by: Alexander Z Lam <azl@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
There are several tracepoints (mostly in RCU), that reference a string
pointer and uses the print format of "%s" to display the string that
exists in the kernel, instead of copying the actual string to the
ring buffer (saves time and ring buffer space).
But this has an issue with userspace tools that read the binary buffers
that has the address of the string but has no access to what the string
itself is. The end result is just output that looks like:
rcu_dyntick: ffffffff818adeaa 1 0
rcu_dyntick: ffffffff818adeb5 0 140000000000000
rcu_dyntick: ffffffff818adeb5 0 140000000000000
rcu_utilization: ffffffff8184333b
rcu_utilization: ffffffff8184333b
The above is pretty useless when read by the userspace tools. Ideally
we would want something that looks like this:
rcu_dyntick: Start 1 0
rcu_dyntick: End 0 140000000000000
rcu_dyntick: Start 140000000000000 0
rcu_callback: rcu_preempt rhp=0xffff880037aff710 func=put_cred_rcu 0/4
rcu_callback: rcu_preempt rhp=0xffff880078961980 func=file_free_rcu 0/5
rcu_dyntick: End 0 1
The trace_printk() which also only stores the address of the string
format instead of recording the string into the buffer itself, exports
the mapping of kernel addresses to format strings via the printk_format
file in the debugfs tracing directory.
The tracepoint strings can use this same method and output the format
to the same file and the userspace tools will be able to decipher
the address without any modification.
The tracepoint strings need its own section to save the strings because
the trace_printk section will cause the trace_printk() buffers to be
allocated if anything exists within the section. trace_printk() is only
used for debugging and should never exist in the kernel, we can not use
the trace_printk sections.
Add a new tracepoint_str section that will also be examined by the output
of the printk_format file.
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
After the previous changes trace_array_cpu->trace_cpu and
trace_array->trace_cpu becomes write-only. Remove these members
and kill "struct trace_cpu" as well.
As a side effect this also removes memset(per_cpu_memory, 0).
It was not needed, alloc_percpu() returns zero-filled memory.
Link: http://lkml.kernel.org/r/20130723152613.GA23741@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Trivial. trace_array->waiter has no users since 6eaaa5d5
"tracing/core: use appropriate waiting on trace_pipe".
Link: http://lkml.kernel.org/r/20130719142036.GA1594@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The selftest for function and function graph tracers are defined as
__init, as they are only executed at boot up. The "tracer" structs
that are associated to those tracers are not setup as __init as they
are used after boot. To stop mismatch warnings, those structures
need to be annotated with __ref_data.
Currently, the tracer structures are defined to __read_mostly, as they
do not really change. But in the future they should be converted to
consts, but that will take a little work because they have a "next"
pointer that gets updated when they are registered. That will have to
wait till the next major release.
Link: http://lkml.kernel.org/r/1373596735.17876.84.camel@gandalf.local.home
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reported-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
were added to 3.10, which includes several bug fixes that have been
marked for stable.
As for new features, there were a few, but nothing to write to LWN about.
These include:
New function trigger called "dump" and "cpudump" that will cause
ftrace to dump its buffer to the console when the function is called.
The difference between "dump" and "cpudump" is that "dump" will dump
the entire contents of the ftrace buffer, where as "cpudump" will only
dump the contents of the ftrace buffer for the CPU that called the function.
Another small enhancement is a new sysctl switch called "traceoff_on_warning"
which, when enabled, will disable tracing if any WARN_ON() is triggered.
This is useful if you want to debug what caused a warning and do not
want to risk losing your trace data by the ring buffer overwriting the
data before you can disable it. There's also a kernel command line
option that will make this enabled at boot up called the same thing.
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Merge tag 'trace-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing changes from Steven Rostedt:
"The majority of the changes here are cleanups for the large changes
that were added to 3.10, which includes several bug fixes that have
been marked for stable.
As for new features, there were a few, but nothing to write to LWN
about. These include:
New function trigger called "dump" and "cpudump" that will cause
ftrace to dump its buffer to the console when the function is called.
The difference between "dump" and "cpudump" is that "dump" will dump
the entire contents of the ftrace buffer, where as "cpudump" will only
dump the contents of the ftrace buffer for the CPU that called the
function.
Another small enhancement is a new sysctl switch called
"traceoff_on_warning" which, when enabled, will disable tracing if any
WARN_ON() is triggered. This is useful if you want to debug what
caused a warning and do not want to risk losing your trace data by the
ring buffer overwriting the data before you can disable it. There's
also a kernel command line option that will make this enabled at boot
up called the same thing"
* tag 'trace-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (34 commits)
tracing: Make tracing_open_generic_{tr,tc}() static
tracing: Remove ftrace() function
tracing: Remove TRACE_EVENT_TYPE enum definition
tracing: Make tracer_tracing_{off,on,is_on}() static
tracing: Fix irqs-off tag display in syscall tracing
uprobes: Fix return value in error handling path
tracing: Fix race between deleting buffer and setting events
tracing: Add trace_array_get/put() to event handling
tracing: Get trace_array ref counts when accessing trace files
tracing: Add trace_array_get/put() to handle instance refs better
tracing: Protect ftrace_trace_arrays list in trace_events.c
tracing: Make trace_marker use the correct per-instance buffer
ftrace: Do not run selftest if command line parameter is set
tracing/kprobes: Don't pass addr=ip to perf_trace_buf_submit()
tracing: Use flag buffer_disabled for irqsoff tracer
tracing/kprobes: Turn trace_probe->files into list_head
tracing: Fix disabling of soft disable
tracing: Add missing syscall_metadata comment
tracing: Simplify code for showing of soft disabled flag
tracing/kprobes: Kill probe_enable_lock
...
Commit a695cb5816 "tracing: Prevent deleting instances when they are being read"
tried to fix a race between deleting a trace instance and reading contents
of a trace file. But it wasn't good enough. The following could crash the kernel:
# cd /sys/kernel/debug/tracing/instances
# ( while :; do mkdir foo; rmdir foo; done ) &
# ( while :; do echo 1 > foo/events/sched/sched_switch 2> /dev/null; done ) &
Luckily this can only be done by root user, but it should be fixed regardless.
The problem is that a delete of the file can happen after the write to the event
is opened, but before the enabling happens.
The solution is to make sure the trace_array is available before succeeding in
opening for write, and incerment the ref counter while opened.
Now the instance can be deleted when the events are writing to the buffer,
but the deletion of the instance will disable all events before the instance
is actually deleted.
Cc: stable@vger.kernel.org # 3.10
Reported-by: Alexander Lam <azl@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
There are multiple places where the ftrace_trace_arrays list is accessed in
trace_events.c without the trace_types_lock held.
Link: http://lkml.kernel.org/r/1372732674-22726-1-git-send-email-azl@google.com
Cc: Vaibhav Nagarnaik <vnagarnaik@google.com>
Cc: David Sharp <dhsharp@google.com>
Cc: Alexander Z Lam <lambchop468@gmail.com>
Cc: stable@vger.kernel.org # 3.10
Signed-off-by: Alexander Z Lam <azl@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
If the kernel command line ftrace filter parameters are set
(ftrace_filter or ftrace_notrace), force the function self test to
pass, with a warning why it was forced.
If the user adds a filter to the kernel command line, it is assumed
that they know what they are doing, and the self test should just not
run instead of failing (which disables function tracing) or clearing
the filter, as that will probably annoy the user.
If the user wants the selftest to run, the message will tell them why
it did not.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Outputting formats of x86-tsc and counter should be a raw format, but after
applying the patch(2b6080f28c), the format was
changed to nanosec. This is because the global variable trace_clock_id was used.
When we use multiple buffers, clock_id of each sub-buffer should be used. Then,
this patch uses tr->clock_id instead of the global variable trace_clock_id.
[ Basically, this fixes a regression where the multibuffer code changed the
trace_clock file to update tr->clock_id but the traces still use the old
global trace_clock_id variable, negating the file's effect. The global
trace_clock_id variable is obsolete and removed. - SR ]
Link: http://lkml.kernel.org/r/20130423013239.22334.7394.stgit@yunodevel
Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull perf updates from Ingo Molnar:
"Features:
- Add "uretprobes" - an optimization to uprobes, like kretprobes are
an optimization to kprobes. "perf probe -x file sym%return" now
works like kretprobes. By Oleg Nesterov.
- Introduce per core aggregation in 'perf stat', from Stephane
Eranian.
- Add memory profiling via PEBS, from Stephane Eranian.
- Event group view for 'annotate' in --stdio, --tui and --gtk, from
Namhyung Kim.
- Add support for AMD NB and L2I "uncore" counters, by Jacob Shin.
- Add Ivy Bridge-EP uncore support, by Zheng Yan
- IBM zEnterprise EC12 oprofile support patchlet from Robert Richter.
- Add perf test entries for checking breakpoint overflow signal
handler issues, from Jiri Olsa.
- Add perf test entry for for checking number of EXIT events, from
Namhyung Kim.
- Add perf test entries for checking --cpu in record and stat, from
Jiri Olsa.
- Introduce perf stat --repeat forever, from Frederik Deweerdt.
- Add --no-demangle to report/top, from Namhyung Kim.
- PowerPC fixes plus a couple of cleanups/optimizations in uprobes
and trace_uprobes, by Oleg Nesterov.
Various fixes and refactorings:
- Fix dependency of the python binding wrt libtraceevent, from
Naohiro Aota.
- Simplify some perf_evlist methods and to allow 'stat' to share code
with 'record' and 'trace', by Arnaldo Carvalho de Melo.
- Remove dead code in related to libtraceevent integration, from
Namhyung Kim.
- Revert "perf sched: Handle PERF_RECORD_EXIT events" to get 'perf
sched lat' back working, by Arnaldo Carvalho de Melo
- We don't use Newt anymore, just plain libslang, by Arnaldo Carvalho
de Melo.
- Kill a bunch of die() calls, from Namhyung Kim.
- Fix build on non-glibc systems due to libio.h absence, from Cody P
Schafer.
- Remove some perf_session and tracing dead code, from David Ahern.
- Honor parallel jobs, fix from Borislav Petkov
- Introduce tools/lib/lk library, initially just removing duplication
among tools/perf and tools/vm. from Borislav Petkov
... and many more I missed to list, see the shortlog and git log for
more details."
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (136 commits)
perf/x86/intel/P4: Robistify P4 PMU types
perf/x86/amd: Fix AMD NB and L2I "uncore" support
perf/x86/amd: Remove old-style NB counter support from perf_event_amd.c
perf/x86: Check all MSRs before passing hw check
perf/x86/amd: Add support for AMD NB and L2I "uncore" counters
perf/x86/intel: Add Ivy Bridge-EP uncore support
perf/x86/intel: Fix SNB-EP CBO and PCU uncore PMU filter management
perf/x86: Avoid kfree() in CPU_{STARTING,DYING}
uprobes/perf: Avoid perf_trace_buf_prepare/submit if ->perf_events is empty
uprobes/tracing: Don't pass addr=ip to perf_trace_buf_submit()
uprobes/tracing: Change create_trace_uprobe() to support uretprobes
uprobes/tracing: Make seq_printf() code uretprobe-friendly
uprobes/tracing: Make register_uprobe_event() paths uretprobe-friendly
uprobes/tracing: Make uprobe_{trace,perf}_print() uretprobe-friendly
uprobes/tracing: Introduce is_ret_probe() and uretprobe_dispatcher()
uprobes/tracing: Introduce uprobe_{trace,perf}_print() helpers
uprobes/tracing: Generalize struct uprobe_trace_entry_head
uprobes/tracing: Kill the pointless local_save_flags/preempt_count calls
uprobes/tracing: Kill the pointless seq_print_ip_sym() call
uprobes/tracing: Kill the pointless task_pt_regs() calls
...
struct uprobe_trace_entry_head has a single member for reporting,
"unsigned long ip". If we want to support uretprobes we need to
create another struct which has "func" and "ret_ip" and duplicate
a lot of functions, like trace_kprobe.c does.
To avoid this copy-and-paste horror we turn ->ip into ->vaddr[]
and add couple of trivial helpers to calculate sizeof/data. This
uglifies the code a bit, but this allows us to avoid a lot more
complications later, when we add the support for ret-probes.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Tested-by: Anton Arapov <anton@redhat.com>
By moving find_event_field() and trace_find_field() into trace_events.c,
the ftrace_common_fields list and trace_get_fields() can become local to
the trace_events.c file.
find_event_field() is renamed to trace_find_event_field() to conform to
the tracing global function names.
Link: http://lkml.kernel.org/r/513D8426.9070109@huawei.com
Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
[ rostedt: Modified trace_find_field() to trace_find_event_field() ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently, the only way to stop the latency tracers from doing function
tracing is to fully disable the function tracer from the proc file
system:
echo 0 > /proc/sys/kernel/ftrace_enabled
This is a big hammer approach as it disables function tracing for
all users. This includes kprobes, perf, stack tracer, etc.
Instead, create a function-trace option that the latency tracers can
check to determine if it should enable function tracing or not.
This option can be set or cleared even while the tracer is active
and the tracers will disable or enable function tracing depending
on how the option was set.
Instead of using the proc file, disable latency function tracing with
echo 0 > /debug/tracing/options/function-trace
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Stanislav Fomichev