perf: Reduce perf_disable() usage

Since the current perf_disable() usage is only an optimization,
remove it for now. This eases the removal of the __weak
hw_perf_enable() interface.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: paulus <paulus@samba.org>
Cc: stephane eranian <eranian@googlemail.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Lin Ming <ming.m.lin@intel.com>
Cc: Yanmin <yanmin_zhang@linux.intel.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: David Miller <davem@davemloft.net>
Cc: Michael Cree <mcree@orcon.net.nz>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 8 insertions, 3 deletions

diff --git a/arch/sh/kernel/perf_event.c b/arch/sh/kernel/perf_event.c
index 8cb206597e0c..d042989ceb45 100644
--- a/arch/sh/kernel/perf_event.c
+++ b/arch/sh/kernel/perf_event.c
@@ -230,11 +230,14 @@ static int sh_pmu_enable(struct perf_event *event)
         struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
         struct hw_perf_event *hwc = &event->hw;
         int idx = hwc->idx;
+        int ret = -EAGAIN;
+
+        perf_disable();
 
         if (test_and_set_bit(idx, cpuc->used_mask)) {
                 idx = find_first_zero_bit(cpuc->used_mask, sh_pmu->num_events);
                 if (idx == sh_pmu->num_events)
-                        return -EAGAIN;
+                        goto out;
 
                 set_bit(idx, cpuc->used_mask);
                 hwc->idx = idx;
@@ -248,8 +251,10 @@ static int sh_pmu_enable(struct perf_event *event)
         sh_pmu->enable(hwc, idx);
 
         perf_event_update_userpage(event);
-
-        return 0;
+        ret = 0;
+out:
+        perf_enable();
+        return ret;
 }
 
 static void sh_pmu_read(struct perf_event *event)