From 5f09fc688936705b2020ca247df39ee27283668a Mon Sep 17 00:00:00 2001 From: Robert Richter Date: Thu, 5 Apr 2012 18:24:42 +0200 Subject: [PATCH] perf/x86: Fix cmpxchg() usage in amd_put_event_constraints() Now the return value of cmpxchg() is used to match an event. The change removes the duplicate event comparison and traverses the list until an event was removed. This also fixes the following warning: arch/x86/kernel/cpu/perf_event_amd.c:170: warning: value computed is not used Signed-off-by: Robert Richter Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1333643084-26776-3-git-send-email-robert.richter@amd.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event_amd.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event_amd.c b/arch/x86/kernel/cpu/perf_event_amd.c index 95e7fe1..589286f 100644 --- a/arch/x86/kernel/cpu/perf_event_amd.c +++ b/arch/x86/kernel/cpu/perf_event_amd.c @@ -205,10 +205,8 @@ static void amd_put_event_constraints(struct cpu_hw_events *cpuc, * when we come here */ for (i = 0; i < x86_pmu.num_counters; i++) { - if (nb->owners[i] == event) { - cmpxchg(nb->owners+i, event, NULL); + if (cmpxchg(nb->owners + i, event, NULL) == event) break; - } } } -- 2.7.4