diff options
| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2010-10-19 14:22:50 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2010-10-22 14:18:26 +0200 |
| commit | 6809b6ea73f7291f2e495d40397f1172c9caa77e (patch) | |
| tree | 3653223bfd80867056da5e4f57be9512c67d706f /arch/x86/kernel/cpu/perf_event.c | |
| parent | 5553be2620ac901c21a25657bd5b59f73254e6d5 (diff) | |
perf, x86: Less disastrous PEBS/BTS buffer allocation failure
Currently PEBS/BTS buffers are allocated when we instantiate the first
event, when this fails everything fails.
This is a problem because esp. BTS tries to allocate a rather large
buffer (64K), which can easily fail.
This patch changes the logic such that when either buffer allocation
fails, we simply don't allow events that would use these facilities,
but continue functioning for all other events.
This logic comes from a much larger patch proposed by Stephane.
Suggested-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Stephane Eranian <eranian@google.com>
LKML-Reference: <20101019134808.354429461@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/cpu/perf_event.c')
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index f369c53315a5..61e78f651060 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -238,6 +238,7 @@ struct x86_pmu { * Intel DebugStore bits */ int bts, pebs; + int bts_active, pebs_active; int pebs_record_size; void (*drain_pebs)(struct pt_regs *regs); struct event_constraint *pebs_constraints; @@ -478,7 +479,7 @@ static int x86_setup_perfctr(struct perf_event *event) if ((attr->config == PERF_COUNT_HW_BRANCH_INSTRUCTIONS) && (hwc->sample_period == 1)) { /* BTS is not supported by this architecture. */ - if (!x86_pmu.bts) + if (!x86_pmu.bts_active) return -EOPNOTSUPP; /* BTS is currently only allowed for user-mode. */ @@ -497,7 +498,7 @@ static int x86_pmu_hw_config(struct perf_event *event) int precise = 0; /* Support for constant skid */ - if (x86_pmu.pebs) { + if (x86_pmu.pebs_active) { precise++; /* Support for IP fixup */ |