Instead of tracking if a context is active or not, track which events
of the context are active. By making it a bitmask of
EVENT_PINNED|EVENT_FLEXIBLE we can simplify some of the scheduling
routines since it can avoid adding events that are already active.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
kernel/perf_event.c | 99 +++++++++++++++++++++++++---------------------------
1 file changed, 48 insertions(+), 51 deletions(-)
Index: linux-2.6/kernel/perf_event.c
===================================================================
--- linux-2.6.orig/kernel/perf_event.c
+++ linux-2.6/kernel/perf_event.c
@@ -1780,8 +1775,9 @@ static void ctx_sched_out(struct perf_ev
enum event_type_t event_type)
{
struct perf_event *event;
+ int is_active = ctx->is_active;
- ctx->is_active = 0;
+ ctx->is_active &= ~event_type;
if (likely(!ctx->nr_events))
return;
@@ -1791,12 +1787,12 @@ static void ctx_sched_out(struct perf_ev
return;
perf_pmu_disable(ctx->pmu);
- if (event_type & EVENT_PINNED) {
+ if ((is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) {
list_for_each_entry(event, &ctx->pinned_groups, group_entry)
group_sched_out(event, cpuctx, ctx);
}
- if (event_type & EVENT_FLEXIBLE) {
+ if ((is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) {
list_for_each_entry(event, &ctx->flexible_groups, group_entry)
group_sched_out(event, cpuctx, ctx);
}
@@ -2075,8 +2071,9 @@ ctx_sched_in(struct perf_event_context *
struct task_struct *task)
{
u64 now;
+ int is_active = ctx->is_active;
- ctx->is_active = 1;
+ ctx->is_active |= event_type;
if (likely(!ctx->nr_events))
return;
@@ -2087,11 +2084,11 @@ ctx_sched_in(struct perf_event_context *
* First go through the list and put on any pinned groups
* in order to give them the best chance of going on.
*/
- if (event_type & EVENT_PINNED)
+ if (!(is_active & EVENT_PINNED) && (event_type & EVENT_PINNED))
ctx_pinned_sched_in(ctx, cpuctx);
/* Then walk through the lower prio flexible groups */
- if (event_type & EVENT_FLEXIBLE)
+ if (!(is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE))
ctx_flexible_sched_in(ctx, cpuctx);
}
--
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