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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-04-06 11:45:04 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-04-07 10:48:56 +0200 |
| commit | f6c7d5fe58b4846ee0cb4b98b6042489705eced4 (patch) | |
| tree | b37bda884e0740489269da5ddc3401ffa61f076e /kernel/perf_counter.c | |
| parent | b6276f353bf490add62dcf7db0ebd75baa3e1a37 (diff) | |
| download | lwn-f6c7d5fe58b4846ee0cb4b98b6042489705eced4.tar.gz lwn-f6c7d5fe58b4846ee0cb4b98b6042489705eced4.zip | |
perf_counter: theres more to overflow than writing events
Prepare for more generic overflow handling. The new perf_counter_overflow()
method will handle the generic bits of the counter overflow, and can return
a !0 return value, in which case the counter should be (soft) disabled, so
that it won't count until it's properly disabled.
XXX: do powerpc and swcounter
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090406094517.812109629@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/perf_counter.c')
| -rw-r--r-- | kernel/perf_counter.c | 29 |
1 files changed, 23 insertions, 6 deletions
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 0a2ade2e4f11..195e976eb07d 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -1800,8 +1800,8 @@ static void perf_output_end(struct perf_output_handle *handle) rcu_read_unlock(); } -void perf_counter_output(struct perf_counter *counter, - int nmi, struct pt_regs *regs) +static void perf_counter_output(struct perf_counter *counter, + int nmi, struct pt_regs *regs) { int ret; u64 record_type = counter->hw_event.record_type; @@ -2034,6 +2034,17 @@ void perf_counter_munmap(unsigned long addr, unsigned long len, } /* + * Generic counter overflow handling. + */ + +int perf_counter_overflow(struct perf_counter *counter, + int nmi, struct pt_regs *regs) +{ + perf_counter_output(counter, nmi, regs); + return 0; +} + +/* * Generic software counter infrastructure */ @@ -2077,6 +2088,7 @@ static void perf_swcounter_set_period(struct perf_counter *counter) static enum hrtimer_restart perf_swcounter_hrtimer(struct hrtimer *hrtimer) { + enum hrtimer_restart ret = HRTIMER_RESTART; struct perf_counter *counter; struct pt_regs *regs; @@ -2092,12 +2104,14 @@ static enum hrtimer_restart perf_swcounter_hrtimer(struct hrtimer *hrtimer) !counter->hw_event.exclude_user) regs = task_pt_regs(current); - if (regs) - perf_counter_output(counter, 0, regs); + if (regs) { + if (perf_counter_overflow(counter, 0, regs)) + ret = HRTIMER_NORESTART; + } hrtimer_forward_now(hrtimer, ns_to_ktime(counter->hw.irq_period)); - return HRTIMER_RESTART; + return ret; } static void perf_swcounter_overflow(struct perf_counter *counter, @@ -2105,7 +2119,10 @@ static void perf_swcounter_overflow(struct perf_counter *counter, { perf_swcounter_update(counter); perf_swcounter_set_period(counter); - perf_counter_output(counter, nmi, regs); + if (perf_counter_overflow(counter, nmi, regs)) + /* soft-disable the counter */ + ; + } static int perf_swcounter_match(struct perf_counter *counter, |