diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/perf_counter.c | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index c05e10354bc9..8c8eaf0625f9 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -1596,7 +1596,11 @@ void perf_counter_wakeup(struct perf_counter *counter) rcu_read_unlock(); wake_up_all(&counter->waitq); - kill_fasync(&counter->fasync, SIGIO, POLL_IN); + + if (counter->pending_kill) { + kill_fasync(&counter->fasync, SIGIO, counter->pending_kill); + counter->pending_kill = 0; + } } /* @@ -1727,6 +1731,7 @@ struct perf_output_handle { unsigned int head; int wakeup; int nmi; + int overflow; }; static inline void __perf_output_wakeup(struct perf_output_handle *handle) @@ -1741,7 +1746,7 @@ static inline void __perf_output_wakeup(struct perf_output_handle *handle) static int perf_output_begin(struct perf_output_handle *handle, struct perf_counter *counter, unsigned int size, - int nmi) + int nmi, int overflow) { struct perf_mmap_data *data; unsigned int offset, head; @@ -1751,8 +1756,9 @@ static int perf_output_begin(struct perf_output_handle *handle, if (!data) goto out; - handle->counter = counter; - handle->nmi = nmi; + handle->counter = counter; + handle->nmi = nmi; + handle->overflow = overflow; if (!data->nr_pages) goto fail; @@ -1816,7 +1822,7 @@ static void perf_output_end(struct perf_output_handle *handle) { int wakeup_events = handle->counter->hw_event.wakeup_events; - if (wakeup_events) { + if (handle->overflow && wakeup_events) { int events = atomic_inc_return(&handle->data->events); if (events >= wakeup_events) { atomic_sub(wakeup_events, &handle->data->events); @@ -1891,7 +1897,7 @@ static void perf_counter_output(struct perf_counter *counter, header.size += sizeof(u64); } - ret = perf_output_begin(&handle, counter, header.size, nmi); + ret = perf_output_begin(&handle, counter, header.size, nmi, 1); if (ret) return; @@ -1955,7 +1961,7 @@ static void perf_counter_mmap_output(struct perf_counter *counter, { struct perf_output_handle handle; int size = mmap_event->event.header.size; - int ret = perf_output_begin(&handle, counter, size, 0); + int ret = perf_output_begin(&handle, counter, size, 0, 0); if (ret) return; @@ -2084,8 +2090,10 @@ int perf_counter_overflow(struct perf_counter *counter, int events = atomic_read(&counter->event_limit); int ret = 0; + counter->pending_kill = POLL_IN; if (events && atomic_dec_and_test(&counter->event_limit)) { ret = 1; + counter->pending_kill = POLL_HUP; if (nmi) { counter->pending_disable = 1; perf_pending_queue(&counter->pending, |