Messages in this thread Patch in this message | | | Date | Wed, 20 May 2009 12:21:22 +0200 | From | Peter Zijlstra <> | Subject | [PATCH 4/4] perf_counter: optimize sched in/out of counters |
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Avoid a function call for !group counters by directly calling the counter function.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> --- kernel/perf_counter.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-)
Index: linux-2.6/kernel/perf_counter.c =================================================================== --- linux-2.6.orig/kernel/perf_counter.c +++ linux-2.6/kernel/perf_counter.c @@ -826,8 +826,12 @@ void __perf_counter_sched_out(struct per perf_disable(); if (ctx->nr_active) { - list_for_each_entry(counter, &ctx->counter_list, list_entry) - group_sched_out(counter, cpuctx, ctx); + list_for_each_entry(counter, &ctx->counter_list, list_entry) { + if (counter != counter->group_leader) + counter_sched_out(counter, cpuctx, ctx); + else + group_sched_out(counter, cpuctx, ctx); + } } perf_enable(); out: @@ -903,8 +907,12 @@ __perf_counter_sched_in(struct perf_coun if (counter->cpu != -1 && counter->cpu != cpu) continue; - if (group_can_go_on(counter, cpuctx, 1)) - group_sched_in(counter, cpuctx, ctx, cpu); + if (counter != counter->group_leader) + counter_sched_in(counter, cpuctx, ctx, cpu); + else { + if (group_can_go_on(counter, cpuctx, 1)) + group_sched_in(counter, cpuctx, ctx, cpu); + } /* * If this pinned group hasn't been scheduled, @@ -932,9 +940,14 @@ __perf_counter_sched_in(struct perf_coun if (counter->cpu != -1 && counter->cpu != cpu) continue; - if (group_can_go_on(counter, cpuctx, can_add_hw)) { - if (group_sched_in(counter, cpuctx, ctx, cpu)) + if (counter != counter->group_leader) { + if (counter_sched_in(counter, cpuctx, ctx, cpu)) can_add_hw = 0; + } else { + if (group_can_go_on(counter, cpuctx, can_add_hw)) { + if (group_sched_in(counter, cpuctx, ctx, cpu)) + can_add_hw = 0; + } } } perf_enable(); --
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