diff options
| author | Tom Zanussi <tom.zanussi@linux.intel.com> | 2013-10-24 08:59:26 -0500 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2013-12-21 22:01:22 -0500 |
| commit | 93e31ffbf417a84fbae518fb46b3ea3f0d8fa6e1 (patch) | |
| tree | c7eb0f81daec69a2505688bb5fcee94e2374be5f /kernel/trace/trace.h | |
| parent | 2a2df321158817811c5dc206dce808e0aa9f6d89 (diff) | |
tracing: Add 'snapshot' event trigger command
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>
Diffstat (limited to 'kernel/trace/trace.h')
| -rw-r--r-- | kernel/trace/trace.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 9775e518fe7..50723e5e2b3 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1211,6 +1211,7 @@ struct event_command { extern int trace_event_enable_disable(struct ftrace_event_file *file, int enable, int soft_disable); +extern int tracing_alloc_snapshot(void); extern const char *__start___trace_bprintk_fmt[]; extern const char *__stop___trace_bprintk_fmt[]; |