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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 <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4cbeeeb7.0aefd80a.6e40.0e2f@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
hifive-unleashed-5.1
Stephane Eranian 2010-10-20 15:25:01 +02:00 committed by Ingo Molnar
parent 96681fc3c9
commit 9ffcfa6f1f
1 changed files with 13 additions and 63 deletions
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76
kernel/perf_event.c
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@ -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);