diff options
| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-03-30 19:07:14 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-04-06 09:30:43 +0200 |
| commit | 394ee07623cf556c8daae2b3c00cf5fea47f0811 (patch) | |
| tree | f3568c9d779c282732c7bbeccb75a4bb3041b857 /kernel | |
| parent | 023c54c42288416b4f43c67bfd5049a76926fad6 (diff) | |
perf_counter: provide generic callchain bits
Provide the generic callchain support bits. If hw_event->callchain is
set the arch specific perf_callchain() function is called upon to
provide a perf_callchain_entry structure filled with the current
callchain.
If it does so, it is added to the overflow output event.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Orig-LKML-Reference: <20090330171024.254266860@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/perf_counter.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index d93e9ddf784..860cdc26bd7 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -1654,6 +1654,17 @@ void perf_counter_do_pending(void) } /* + * Callchain support -- arch specific + */ + +struct perf_callchain_entry * +__attribute__((weak)) +perf_callchain(struct pt_regs *regs) +{ + return NULL; +} + +/* * Output */ @@ -1764,6 +1775,8 @@ static void perf_output_simple(struct perf_counter *counter, struct { u32 pid, tid; } tid_entry; + struct perf_callchain_entry *callchain = NULL; + int callchain_size = 0; header.type = PERF_EVENT_OVERFLOW; header.size = sizeof(header); @@ -1781,6 +1794,17 @@ static void perf_output_simple(struct perf_counter *counter, header.size += sizeof(tid_entry); } + if (counter->hw_event.callchain) { + callchain = perf_callchain(regs); + + if (callchain) { + callchain_size = (1 + callchain->nr) * sizeof(u64); + + header.type |= __PERF_EVENT_CALLCHAIN; + header.size += callchain_size; + } + } + ret = perf_output_begin(&handle, counter, header.size, nmi); if (ret) return; @@ -1791,6 +1815,9 @@ static void perf_output_simple(struct perf_counter *counter, if (counter->hw_event.include_tid) perf_output_put(&handle, tid_entry); + if (callchain) + perf_output_copy(&handle, callchain, callchain_size); + perf_output_end(&handle); } |