From 8c8a9b25b5de3f1eeac721cf34f4379e56d5d694 Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Tue, 18 Jan 2011 21:44:04 +1100 Subject: [PATCH] powerpc, perf: Fix frequency calculation for overflowing counters (FSL version) When fixing the frequency calculations for perf on powerpc I forgot to fix the FSL version. If we dont set event->hw.last_period the frequency to period calculations in perf go haywire and we continually throttle/unthrottle the PMU. Signed-off-by: Anton Blanchard Acked-by: Benjamin Herrenschmidt Cc: Scott Wood Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: linuxppc-dev@lists.ozlabs.org Cc: Peter Zijlstra LKML-Reference: <20110118214404.2f42e634@kryten> Signed-off-by: Ingo Molnar --- arch/powerpc/kernel/perf_event_fsl_emb.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/kernel/perf_event_fsl_emb.c b/arch/powerpc/kernel/perf_event_fsl_emb.c index 4dcf5f831e9d..b0dc8f7069cd 100644 --- a/arch/powerpc/kernel/perf_event_fsl_emb.c +++ b/arch/powerpc/kernel/perf_event_fsl_emb.c @@ -596,6 +596,7 @@ static void record_and_restart(struct perf_event *event, unsigned long val, if (left <= 0) left = period; record = 1; + event->hw.last_period = event->hw.sample_period; } if (left < 0x80000000LL) val = 0x80000000LL - left; -- 2.20.1