From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark.rutland@arm.com (Mark Rutland) Date: Wed, 27 Apr 2011 10:57:16 +0100 Subject: [PATCH] ARM: perf: remove erroneous check on active_events Message-ID: <1303898236-14263-1-git-send-email-mark.rutland@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org When initialising a PMU, there is a check to protect against races with other CPUs filling all of the available event slots. Since armpmu_add checks that an event can be scheduled, we do not need to do this at initialisation time. Furthermore the current code is broken because it assumes that atomic_inc_not_zero will unconditionally increment active_counts and then tries to decrement it again on failure. This patch removes the broken, redundant code. Signed-off-by: Mark Rutland Acked-by: Will Deacon Cc: Will Deacon Cc: Jamie Iles --- arch/arm/kernel/perf_event.c | 5 ----- 1 files changed, 0 insertions(+), 5 deletions(-) diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index fd6403c..29a0cf8 100644 --- a/arch/arm/kernel/perf_event.c +++ b/arch/arm/kernel/perf_event.c @@ -560,11 +560,6 @@ static int armpmu_event_init(struct perf_event *event) event->destroy = hw_perf_event_destroy; if (!atomic_inc_not_zero(&active_events)) { - if (atomic_read(&active_events) > armpmu->num_events) { - atomic_dec(&active_events); - return -ENOSPC; - } - mutex_lock(&pmu_reserve_mutex); if (atomic_read(&active_events) == 0) { err = armpmu_reserve_hardware(); -- 1.7.0.4