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authorAdrian Hunter <adrian.hunter@intel.com>2014-05-28 11:45:04 +0300
committerIngo Molnar <mingo@kernel.org>2014-06-06 07:56:22 +0200
commit82b897782d10fcc4930c9d4a15b175348fdd2871 (patch)
tree82bc0bb22ef1379b901d4fce582584b6776a91ea /include/linux/perf_event.h
parentec00010972a0971b2c1da4fbe4e5c7d8ed1ecb05 (diff)
perf: Differentiate exec() and non-exec() comm events
perf tools like 'perf report' can aggregate samples by comm strings, which generally works. However, there are other potential use-cases. For example, to pair up 'calls' with 'returns' accurately (from branch events like Intel BTS) it is necessary to identify whether the process has exec'd. Although a comm event is generated when an 'exec' happens it is also generated whenever the comm string is changed on a whim (e.g. by prctl PR_SET_NAME). This patch adds a flag to the comm event to differentiate one case from the other. In order to determine whether the kernel supports the new flag, a selection bit named 'exec' is added to struct perf_event_attr. The bit does nothing but will cause perf_event_open() to fail if the bit is set on kernels that do not have it defined. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/537D9EBE.7030806@intel.com Cc: Paul Mackerras <paulus@samba.org> Cc: Dave Jones <davej@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/perf_event.h')
-rw-r--r--include/linux/perf_event.h4
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index b4c1d4685bf0..707617a8c0f6 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -707,7 +707,7 @@ extern int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *
extern int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks);
extern void perf_event_exec(void);
-extern void perf_event_comm(struct task_struct *tsk);
+extern void perf_event_comm(struct task_struct *tsk, bool exec);
extern void perf_event_fork(struct task_struct *tsk);
/* Callchains */
@@ -815,7 +815,7 @@ static inline int perf_unregister_guest_info_callbacks
static inline void perf_event_mmap(struct vm_area_struct *vma) { }
static inline void perf_event_exec(void) { }
-static inline void perf_event_comm(struct task_struct *tsk) { }
+static inline void perf_event_comm(struct task_struct *tsk, bool exec) { }
static inline void perf_event_fork(struct task_struct *tsk) { }
static inline void perf_event_init(void) { }
static inline int perf_swevent_get_recursion_context(void) { return -1; }