From 9e350de37ac9607012fcf9c5314a28fbddf8f43c Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 10 Jun 2009 21:34:59 +0200 Subject: perf_counter: Accurate period data We currently log hw.sample_period for PERF_SAMPLE_PERIOD, however this is incorrect. When we adjust the period, it will only take effect the next cycle but report it for the current cycle. So when we adjust the period for every cycle, we're always wrong. Solve this by keeping track of the last_period. Signed-off-by: Peter Zijlstra Cc: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo LKML-Reference: Signed-off-by: Ingo Molnar --- include/linux/perf_counter.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index d8c0eb480f9..5b966472b45 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -366,6 +366,7 @@ struct hw_perf_counter { }; atomic64_t prev_count; u64 sample_period; + u64 last_period; atomic64_t period_left; u64 interrupts; @@ -606,8 +607,9 @@ extern int hw_perf_group_sched_in(struct perf_counter *group_leader, extern void perf_counter_update_userpage(struct perf_counter *counter); struct perf_sample_data { - struct pt_regs *regs; - u64 addr; + struct pt_regs *regs; + u64 addr; + u64 period; }; extern int perf_counter_overflow(struct perf_counter *counter, int nmi, -- cgit v1.2.3-70-g09d2