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>

8 files changed, 48 insertions, 59 deletions

diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index f62f9db35db3..afc92c580d18 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -277,6 +277,8 @@ armpmu_enable(struct perf_event *event)
         int idx;
         int err = 0;
 
+        perf_disable();
+
         /* If we don't have a space for the counter then finish early. */
         idx = armpmu->get_event_idx(cpuc, hwc);
         if (idx < 0) {
@@ -303,6 +305,7 @@ armpmu_enable(struct perf_event *event)
         perf_event_update_userpage(event);
 
 out:
+        perf_enable();
         return err;
 }
 
diff --git a/arch/powerpc/kernel/perf_event.c b/arch/powerpc/kernel/perf_event.c
index 19131b2614b9..c1408821dbc2 100644
--- a/arch/powerpc/kernel/perf_event.c
+++ b/arch/powerpc/kernel/perf_event.c
@@ -861,6 +861,7 @@ void power_pmu_start_txn(struct pmu *pmu)
 {
         struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
 
+        perf_disable();
         cpuhw->group_flag |= PERF_EVENT_TXN;
         cpuhw->n_txn_start = cpuhw->n_events;
 }
@@ -875,6 +876,7 @@ void power_pmu_cancel_txn(struct pmu *pmu)
         struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
 
         cpuhw->group_flag &= ~PERF_EVENT_TXN;
+        perf_enable();
 }
 
 /*
@@ -901,6 +903,7 @@ int power_pmu_commit_txn(struct pmu *pmu)
                 cpuhw->event[i]->hw.config = cpuhw->events[i];
 
         cpuhw->group_flag &= ~PERF_EVENT_TXN;
+        perf_enable();
         return 0;
 }
 
diff --git a/arch/powerpc/kernel/perf_event_fsl_emb.c b/arch/powerpc/kernel/perf_event_fsl_emb.c
index ea6a804e43fd..9bc84a7fd901 100644
--- a/arch/powerpc/kernel/perf_event_fsl_emb.c
+++ b/arch/powerpc/kernel/perf_event_fsl_emb.c
@@ -262,7 +262,7 @@ static int collect_events(struct perf_event *group, int max_count,
         return n;
 }
 
-/* perf must be disabled, context locked on entry */
+/* context locked on entry */
 static int fsl_emb_pmu_enable(struct perf_event *event)
 {
         struct cpu_hw_events *cpuhw;
@@ -271,6 +271,7 @@ static int fsl_emb_pmu_enable(struct perf_event *event)
         u64 val;
         int i;
 
+        perf_disable();
         cpuhw = &get_cpu_var(cpu_hw_events);
 
         if (event->hw.config & FSL_EMB_EVENT_RESTRICTED)
@@ -310,15 +311,17 @@ static int fsl_emb_pmu_enable(struct perf_event *event)
         ret = 0;
  out:
         put_cpu_var(cpu_hw_events);
+        perf_enable();
         return ret;
 }
 
-/* perf must be disabled, context locked on entry */
+/* context locked on entry */
 static void fsl_emb_pmu_disable(struct perf_event *event)
 {
         struct cpu_hw_events *cpuhw;
         int i = event->hw.idx;
 
+        perf_disable();
         if (i < 0)
                 goto out;
 
@@ -346,6 +349,7 @@ static void fsl_emb_pmu_disable(struct perf_event *event)
         cpuhw->n_events--;
 
  out:
+        perf_enable();
         put_cpu_var(cpu_hw_events);
 }
 
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)
diff --git a/arch/sparc/kernel/perf_event.c b/arch/sparc/kernel/perf_event.c
index bed4327f5a7a..d0131deeeaf6 100644
--- a/arch/sparc/kernel/perf_event.c
+++ b/arch/sparc/kernel/perf_event.c
@@ -1113,6 +1113,7 @@ static void sparc_pmu_start_txn(struct pmu *pmu)
 {
         struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
 
+        perf_disable();
         cpuhw->group_flag |= PERF_EVENT_TXN;
 }
 
@@ -1126,6 +1127,7 @@ static void sparc_pmu_cancel_txn(struct pmu *pmu)
         struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
 
         cpuhw->group_flag &= ~PERF_EVENT_TXN;
+        perf_enable();
 }
 
 /*
@@ -1149,6 +1151,7 @@ static int sparc_pmu_commit_txn(struct pmu *pmu)