From d2bfaea3e508a3085f0d6acde0b6ff938423ab0e Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Tue, 19 Oct 2010 14:22:50 +0200
Subject: [PATCH] --- yaml --- r: 218633 b: refs/heads/master c:
 6809b6ea73f7291f2e495d40397f1172c9caa77e h: refs/heads/master i:   218631:
 7148736f542e441e0840f6d5e5671d2027481aaa v: v3

---
 [refs]                                        |  2 +-
 trunk/arch/x86/kernel/cpu/perf_event.c        |  5 +-
 .../arch/x86/kernel/cpu/perf_event_intel_ds.c | 58 ++++++++++++++-----
 3 files changed, 48 insertions(+), 17 deletions(-)

diff --git a/[refs] b/[refs]
index 5ce020c12c89..1a0333da2b5d 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 5553be2620ac901c21a25657bd5b59f73254e6d5
+refs/heads/master: 6809b6ea73f7291f2e495d40397f1172c9caa77e
diff --git a/trunk/arch/x86/kernel/cpu/perf_event.c b/trunk/arch/x86/kernel/cpu/perf_event.c
index f369c53315a5..61e78f651060 100644
--- a/trunk/arch/x86/kernel/cpu/perf_event.c
+++ b/trunk/arch/x86/kernel/cpu/perf_event.c
@@ -238,6 +238,7 @@ struct x86_pmu {
 	 * Intel DebugStore bits
 	 */
 	int		bts, pebs;
+	int		bts_active, pebs_active;
 	int		pebs_record_size;
 	void		(*drain_pebs)(struct pt_regs *regs);
 	struct event_constraint *pebs_constraints;
@@ -478,7 +479,7 @@ static int x86_setup_perfctr(struct perf_event *event)
 	if ((attr->config == PERF_COUNT_HW_BRANCH_INSTRUCTIONS) &&
 	    (hwc->sample_period == 1)) {
 		/* BTS is not supported by this architecture. */
-		if (!x86_pmu.bts)
+		if (!x86_pmu.bts_active)
 			return -EOPNOTSUPP;
 
 		/* BTS is currently only allowed for user-mode. */
@@ -497,7 +498,7 @@ static int x86_pmu_hw_config(struct perf_event *event)
 		int precise = 0;
 
 		/* Support for constant skid */
-		if (x86_pmu.pebs) {
+		if (x86_pmu.pebs_active) {
 			precise++;
 
 			/* Support for IP fixup */
diff --git a/trunk/arch/x86/kernel/cpu/perf_event_intel_ds.c b/trunk/arch/x86/kernel/cpu/perf_event_intel_ds.c
index 3c86f4d2f02d..05c7db68277b 100644
--- a/trunk/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/trunk/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -193,36 +193,66 @@ static void release_ds_buffers(void)
 
 static int reserve_ds_buffers(void)
 {
-	int cpu, err = 0;
+	int bts_err = 0, pebs_err = 0;
+	int cpu;
+
+	x86_pmu.bts_active = 0;
+	x86_pmu.pebs_active = 0;
 
 	if (!x86_pmu.bts && !x86_pmu.pebs)
 		return 0;
 
+	if (!x86_pmu.bts)
+		bts_err = 1;
+
+	if (!x86_pmu.pebs)
+		pebs_err = 1;
+
 	get_online_cpus();
 
 	for_each_possible_cpu(cpu) {
-		if (alloc_ds_buffer(cpu))
-			break;
+		if (alloc_ds_buffer(cpu)) {
+			bts_err = 1;
+			pebs_err = 1;
+		}
 
-		if (alloc_bts_buffer(cpu))
-			break;
+		if (!bts_err && alloc_bts_buffer(cpu))
+			bts_err = 1;
+
+		if (!pebs_err && alloc_pebs_buffer(cpu))
+			pebs_err = 1;
 
-		if (alloc_pebs_buffer(cpu))
+		if (bts_err && pebs_err)
 			break;
+	}
+
+	if (bts_err) {
+		for_each_possible_cpu(cpu)
+			release_bts_buffer(cpu);
+	}
 
-		err = 0;
+	if (pebs_err) {
+		for_each_possible_cpu(cpu)
+			release_pebs_buffer(cpu);
 	}
 
-	if (err)
-		release_ds_buffers();
-	else {
+	if (bts_err && pebs_err) {
+		for_each_possible_cpu(cpu)
+			release_ds_buffer(cpu);
+	} else {
+		if (x86_pmu.bts && !bts_err)
+			x86_pmu.bts_active = 1;
+
+		if (x86_pmu.pebs && !pebs_err)
+			x86_pmu.pebs_active = 1;
+
 		for_each_online_cpu(cpu)
 			init_debug_store_on_cpu(cpu);
 	}
 
 	put_online_cpus();
 
-	return err;
+	return 0;
 }
 
 /*
@@ -287,7 +317,7 @@ static int intel_pmu_drain_bts_buffer(void)
 	if (!event)
 		return 0;
 
-	if (!ds)
+	if (!x86_pmu.bts_active)
 		return 0;
 
 	at  = (struct bts_record *)(unsigned long)ds->bts_buffer_base;
@@ -557,7 +587,7 @@ static void intel_pmu_drain_pebs_core(struct pt_regs *iregs)
 	struct pebs_record_core *at, *top;
 	int n;
 
-	if (!ds || !x86_pmu.pebs)
+	if (!x86_pmu.pebs_active)
 		return;
 
 	at  = (struct pebs_record_core *)(unsigned long)ds->pebs_buffer_base;
@@ -599,7 +629,7 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs)
 	u64 status = 0;
 	int bit, n;
 
-	if (!ds || !x86_pmu.pebs)
+	if (!x86_pmu.pebs_active)
 		return;
 
 	at  = (struct pebs_record_nhm *)(unsigned long)ds->pebs_buffer_base;