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authorTom Zanussi <tom.zanussi@linux.intel.com>2013-10-24 08:59:26 -0500
committerSteven Rostedt <rostedt@goodmis.org>2013-12-21 22:01:22 -0500
commit93e31ffbf417a84fbae518fb46b3ea3f0d8fa6e1 (patch)
treec7eb0f81daec69a2505688bb5fcee94e2374be5f /include/linux/ftrace_event.h
parent2a2df321158817811c5dc206dce808e0aa9f6d89 (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 'include/linux/ftrace_event.h')
-rw-r--r--include/linux/ftrace_event.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 711c4dcfe8b7..6efa8c2745b5 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -346,6 +346,7 @@ struct ftrace_event_file {
enum event_trigger_type {
ETT_NONE = (0),
ETT_TRACE_ONOFF = (1 << 0),
+ ETT_SNAPSHOT = (1 << 1),
};
extern void destroy_preds(struct ftrace_event_file *file);