From f3d1d36b1ca084490c35bb938582d3dd2b632458 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Mon, 6 Apr 2009 11:45:04 +0200
Subject: [PATCH] --- yaml --- r: 147328 b: refs/heads/master c:
 f6c7d5fe58b4846ee0cb4b98b6042489705eced4 h: refs/heads/master v: v3

---
 [refs]                                   |  2 +-
 trunk/arch/powerpc/kernel/perf_counter.c |  2 +-
 trunk/arch/x86/kernel/cpu/perf_counter.c |  3 ++-
 trunk/include/linux/perf_counter.h       |  4 ++--
 trunk/kernel/perf_counter.c              | 29 +++++++++++++++++++-----
 5 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/[refs] b/[refs]
index 5c9f5dc2bac3..255bec7cab89 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b6276f353bf490add62dcf7db0ebd75baa3e1a37
+refs/heads/master: f6c7d5fe58b4846ee0cb4b98b6042489705eced4
diff --git a/trunk/arch/powerpc/kernel/perf_counter.c b/trunk/arch/powerpc/kernel/perf_counter.c
index 0a4d14f279ae..f88c35d0710a 100644
--- a/trunk/arch/powerpc/kernel/perf_counter.c
+++ b/trunk/arch/powerpc/kernel/perf_counter.c
@@ -732,7 +732,7 @@ static void record_and_restart(struct perf_counter *counter, long val,
 	 * Finally record data if requested.
 	 */
 	if (record)
-		perf_counter_output(counter, 1, regs);
+		perf_counter_overflow(counter, 1, regs);
 }
 
 /*
diff --git a/trunk/arch/x86/kernel/cpu/perf_counter.c b/trunk/arch/x86/kernel/cpu/perf_counter.c
index 438415866fe4..1116a41bc7b5 100644
--- a/trunk/arch/x86/kernel/cpu/perf_counter.c
+++ b/trunk/arch/x86/kernel/cpu/perf_counter.c
@@ -800,7 +800,8 @@ static int __smp_perf_counter_interrupt(struct pt_regs *regs, int nmi)
 			continue;
 
 		perf_save_and_restart(counter);
-		perf_counter_output(counter, nmi, regs);
+		if (perf_counter_overflow(counter, nmi, regs))
+			__pmc_generic_disable(counter, &counter->hw, bit);
 	}
 
 	hw_perf_ack_status(ack);
diff --git a/trunk/include/linux/perf_counter.h b/trunk/include/linux/perf_counter.h
index 977fb15a53f3..ca2d4df29e0c 100644
--- a/trunk/include/linux/perf_counter.h
+++ b/trunk/include/linux/perf_counter.h
@@ -491,8 +491,8 @@ extern int hw_perf_group_sched_in(struct perf_counter *group_leader,
 	       struct perf_counter_context *ctx, int cpu);
 extern void perf_counter_update_userpage(struct perf_counter *counter);
 
-extern void perf_counter_output(struct perf_counter *counter,
-				int nmi, struct pt_regs *regs);
+extern int perf_counter_overflow(struct perf_counter *counter,
+				 int nmi, struct pt_regs *regs);
 /*
  * Return 1 for a software counter, 0 for a hardware counter
  */
diff --git a/trunk/kernel/perf_counter.c b/trunk/kernel/perf_counter.c
index 0a2ade2e4f11..195e976eb07d 100644
--- a/trunk/kernel/perf_counter.c
+++ b/trunk/kernel/perf_counter.c
@@ -1800,8 +1800,8 @@ static void perf_output_end(struct perf_output_handle *handle)
 	rcu_read_unlock();
 }
 
-void perf_counter_output(struct perf_counter *counter,
-			 int nmi, struct pt_regs *regs)
+static void perf_counter_output(struct perf_counter *counter,
+				int nmi, struct pt_regs *regs)
 {
 	int ret;
 	u64 record_type = counter->hw_event.record_type;
@@ -2033,6 +2033,17 @@ void perf_counter_munmap(unsigned long addr, unsigned long len,
 	perf_counter_mmap_event(&mmap_event);
 }
 
+/*
+ * Generic counter overflow handling.
+ */
+
+int perf_counter_overflow(struct perf_counter *counter,
+			  int nmi, struct pt_regs *regs)
+{
+	perf_counter_output(counter, nmi, regs);
+	return 0;
+}
+
 /*
  * Generic software counter infrastructure
  */
@@ -2077,6 +2088,7 @@ static void perf_swcounter_set_period(struct perf_counter *counter)
 
 static enum hrtimer_restart perf_swcounter_hrtimer(struct hrtimer *hrtimer)
 {
+	enum hrtimer_restart ret = HRTIMER_RESTART;
 	struct perf_counter *counter;
 	struct pt_regs *regs;
 
@@ -2092,12 +2104,14 @@ static enum hrtimer_restart perf_swcounter_hrtimer(struct hrtimer *hrtimer)
 			!counter->hw_event.exclude_user)
 		regs = task_pt_regs(current);
 
-	if (regs)
-		perf_counter_output(counter, 0, regs);
+	if (regs) {
+		if (perf_counter_overflow(counter, 0, regs))
+			ret = HRTIMER_NORESTART;
+	}
 
 	hrtimer_forward_now(hrtimer, ns_to_ktime(counter->hw.irq_period));
 
-	return HRTIMER_RESTART;
+	return ret;
 }
 
 static void perf_swcounter_overflow(struct perf_counter *counter,
@@ -2105,7 +2119,10 @@ static void perf_swcounter_overflow(struct perf_counter *counter,
 {
 	perf_swcounter_update(counter);
 	perf_swcounter_set_period(counter);
-	perf_counter_output(counter, nmi, regs);
+	if (perf_counter_overflow(counter, nmi, regs))
+		/* soft-disable the counter */
+		;
+
 }
 
 static int perf_swcounter_match(struct perf_counter *counter,