From 9ffcfa6f1f63eeac15555b745c292eb9f59130f6 Mon Sep 17 00:00:00 2001 From: Stephane Eranian Date: Wed, 20 Oct 2010 15:25:01 +0200 Subject: [PATCH] perf_events: Revert: Fix transaction recovery in group_sched_in() This patch reverts commit 8e5fc1a (perf_events: Fix transaction recovery in group_sched_in()) because it had one flaw in case the group could never be scheduled. It would cause time_enabled to get negative. Signed-off-by: Stephane Eranian Signed-off-by: Peter Zijlstra LKML-Reference: <4cbeeeb7.0aefd80a.6e40.0e2f@mx.google.com> Signed-off-by: Ingo Molnar --- kernel/perf_event.c | 76 +++++++++-------------------------------------------- 1 file changed, 13 insertions(+), 63 deletions(-) diff --git a/kernel/perf_event.c b/kernel/perf_event.c index f309e80..39afdb0 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -417,8 +417,8 @@ event_filter_match(struct perf_event *event) return event->cpu == -1 || event->cpu == smp_processor_id(); } -static int -__event_sched_out(struct perf_event *event, +static void +event_sched_out(struct perf_event *event, struct perf_cpu_context *cpuctx, struct perf_event_context *ctx) { @@ -437,13 +437,14 @@ __event_sched_out(struct perf_event *event, } if (event->state != PERF_EVENT_STATE_ACTIVE) - return 0; + return; 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; @@ -452,19 +453,6 @@ __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 @@ -664,7 +652,7 @@ 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) { @@ -684,6 +672,8 @@ __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++; @@ -694,35 +684,6 @@ __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, @@ -736,13 +697,7 @@ group_sched_in(struct perf_event *group_event, pmu->start_txn(pmu); - /* - * 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)) { + if (event_sched_in(group_event, cpuctx, ctx)) { pmu->cancel_txn(pmu); return -EAGAIN; } @@ -751,31 +706,26 @@ 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)) { - /* commit tstamp_running */ - group_commit_event_sched_in(group_event, cpuctx, ctx); + if (!pmu->commit_txn(pmu)) 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); -- 2.7.4