Commit-ID: ba040653b48d32afa8b6c3331eae97c6bbb66f03
Gitweb: http://git.kernel.org/tip/ba040653b48d32afa8b6c3331eae97c6bbb66f03
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Fri, 22 May 2015 11:36:13 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 27 May 2015 09:17:46 +0200
perf/x86/intel: Simplify put_exclusive_constraints()
Don't bother with taking locks if we're not actually going to do
anything. Also, drop the _irqsave(), this is very much only called
from IRQ-disabled context.
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vince Weaver <vincent.weaver@xxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/kernel/cpu/perf_event_intel.c | 29 +++++++++++++++--------------
1 file changed, 15 insertions(+), 14 deletions(-)
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index f320143..74f19d9 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -2130,7 +2130,6 @@ static void intel_put_excl_constraints(struct cpu_hw_events *cpuc,
struct intel_excl_cntrs *excl_cntrs = cpuc->excl_cntrs;
int tid = cpuc->excl_thread_id;
struct intel_excl_states *xl;
- unsigned long flags = 0; /* keep compiler happy */
/*
* nothing needed if in group validation mode
@@ -2141,7 +2140,6 @@ static void intel_put_excl_constraints(struct cpu_hw_events *cpuc,
if (WARN_ON_ONCE(!excl_cntrs))
return;
- xl = &excl_cntrs->states[tid];
if (hwc->flags & PERF_X86_EVENT_EXCL_ACCT) {
hwc->flags &= ~PERF_X86_EVENT_EXCL_ACCT;
if (!--cpuc->n_excl)
@@ -2149,22 +2147,25 @@ static void intel_put_excl_constraints(struct cpu_hw_events *cpuc,
}
/*
- * put_constraint may be called from x86_schedule_events()
- * which already has the lock held so here make locking
- * conditional
+ * If event was actually assigned, then mark the counter state as
+ * unused now.
*/
- if (!xl->sched_started)
- raw_spin_lock_irqsave(&excl_cntrs->lock, flags);
+ if (hwc->idx >= 0) {
+ xl = &excl_cntrs->states[tid];
+
+ /*
+ * put_constraint may be called from x86_schedule_events()
+ * which already has the lock held so here make locking
+ * conditional.
+ */
+ if (!xl->sched_started)
+ raw_spin_lock(&excl_cntrs->lock);
- /*
- * if event was actually assigned, then mark the
- * counter state as unused now
- */
- if (hwc->idx >= 0)
xl->state[hwc->idx] = INTEL_EXCL_UNUSED;
- if (!xl->sched_started)
- raw_spin_unlock_irqrestore(&excl_cntrs->lock, flags);
+ if (!xl->sched_started)
+ raw_spin_unlock(&excl_cntrs->lock);
+ }
}
static void
--
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