diff options
| -rw-r--r-- | kernel/perf_event.c | 76 |
1 files changed, 63 insertions, 13 deletions
diff --git a/kernel/perf_event.c b/kernel/perf_event.c index e7eeba1794f..634f86a4b2f 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -412,8 +412,8 @@ event_filter_match(struct perf_event *event) return event->cpu == -1 || event->cpu == smp_processor_id(); } -static void -event_sched_out(struct perf_event *event, +static int +__event_sched_out(struct perf_event *event, struct perf_cpu_context *cpuctx, struct perf_event_context *ctx) { @@ -432,14 +432,13 @@ event_sched_out(struct perf_event *event, } if (event->state != PERF_EVENT_STATE_ACTIVE) - return; + return 0; event->state = PERF_EVENT_STATE_INACTIVE; if (event->pending_disable) { event->pending_disable = 0; event->state = PERF_EVENT_STATE_OFF; } - event->tstamp_stopped = ctx->time; event->pmu->del(event, 0); event->oncpu = -1; @@ -448,6 +447,19 @@ event_sched_out(struct perf_event *event, ctx->nr_active--; if (event->attr.exclusive || !cpuctx->active_oncpu) cpuctx->exclusive = 0; + return 1; +} + +static void +event_sched_out(struct perf_event *event, + struct perf_cpu_context *cpuctx, + struct perf_event_context *ctx) +{ + int ret; + + ret = __event_sched_out(event, cpuctx, ctx); + if (ret) + event->tstamp_stopped = ctx->time; } static void @@ -647,7 +659,7 @@ retry: } static int -event_sched_in(struct perf_event *event, +__event_sched_in(struct perf_event *event, struct perf_cpu_context *cpuctx, struct perf_event_context *ctx) { @@ -667,8 +679,6 @@ event_sched_in(struct perf_event *event, return -EAGAIN; } - event->tstamp_running += ctx->time - event->tstamp_stopped; - if (!is_software_event(event)) cpuctx->active_oncpu++; ctx->nr_active++; @@ -679,6 +689,35 @@ event_sched_in(struct perf_event *event, return 0; } +static inline int +event_sched_in(struct perf_event *event, + struct perf_cpu_context *cpuctx, + struct perf_event_context *ctx) +{ + int ret = __event_sched_in(event, cpuctx, ctx); + if (ret) + return ret; + event->tstamp_running += ctx->time - event->tstamp_stopped; + return 0; +} + +static void +group_commit_event_sched_in(struct perf_event *group_event, + struct perf_cpu_context *cpuctx, + struct perf_event_context *ctx) +{ + struct perf_event *event; + u64 now = ctx->time; + + group_event->tstamp_running += now - group_event->tstamp_stopped; + /* + * Schedule in siblings as one group (if any): + */ + list_for_each_entry(event, &group_event->sibling_list, group_entry) { + event->tstamp_running += now - event->tstamp_stopped; + } +} + static int group_sched_in(struct perf_event *group_event, struct perf_cpu_context *cpuctx, @@ -692,7 +731,13 @@ group_sched_in(struct perf_event *group_event, pmu->start_txn(pmu); - if (event_sched_in(group_event, cpuctx, ctx)) { + /* + * use __event_sched_in() to delay updating tstamp_running + * until the transaction is committed. In case of failure + * we will keep an unmodified tstamp_running which is a + * requirement to get correct timing information + */ + if (__event_sched_in(group_event, cpuctx, ctx)) { pmu->cancel_txn(pmu); return -EAGAIN; } @@ -701,26 +746,31 @@ group_sched_in(struct perf_event *group_event, * Schedule in siblings as one group (if any): */ list_for_each_entry(event, &group_event->sibling_list, group_entry) { - if (event_sched_in(event, cpuctx, ctx)) { + if (__event_sched_in(event, cpuctx, ctx)) { partial_group = event; goto group_error; } } - if (!pmu->commit_txn(pmu)) + if (!pmu->commit_txn(pmu)) { + /* commit tstamp_running */ + group_commit_event_sched_in(group_event, cpuctx, ctx); return 0; - + } group_error: /* * Groups can be scheduled in as one unit only, so undo any * partial group before returning: + * + * use __event_sched_out() to avoid updating tstamp_stopped + * because the event never actually ran */ list_for_each_entry(event, &group_event->sibling_list, group_entry) { if (event == partial_group) break; - event_sched_out(event, cpuctx, ctx); + __event_sched_out(event, cpuctx, ctx); } - event_sched_out(group_event, cpuctx, ctx); + __event_sched_out(group_event, cpuctx, ctx); pmu->cancel_txn(pmu); |