---

yaml --- r: 304886 b: refs/heads/master c: 6accb9c h: refs/heads/master v: v3
git-mirror · May 9, 2012 · 4fc9355 · 4fc9355
1 parent 7be0f58
commit 4fc9355
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Showing 2 changed files with 17 additions and 3 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 7bf352384fda3f678a283928c6c5b2cd9da877e4
+refs/heads/master: 6accb9cf76080422d400a641d9068b6b2a2c216f
diff --git a/trunk/arch/x86/kernel/cpu/perf_event_amd_ibs.c b/trunk/arch/x86/kernel/cpu/perf_event_amd_ibs.c
@@ -162,9 +162,16 @@ static int perf_ibs_init(struct perf_event *event)
 		if (config & perf_ibs->cnt_mask)
 			/* raw max_cnt may not be set */
 			return -EINVAL;
-		if (hwc->sample_period & 0x0f)
-			/* lower 4 bits can not be set in ibs max cnt */
+		if (!event->attr.sample_freq && hwc->sample_period & 0x0f)
+			/*
+			 * lower 4 bits can not be set in ibs max cnt,
+			 * but allowing it in case we adjust the
+			 * sample period to set a frequency.
+			 */
 			return -EINVAL;
+		hwc->sample_period &= ~0x0FULL;
+		if (!hwc->sample_period)
+			hwc->sample_period = 0x10;
 	} else {
 		max_cnt = config & perf_ibs->cnt_mask;
 		config &= ~perf_ibs->cnt_mask;
@@ -175,6 +182,13 @@ static int perf_ibs_init(struct perf_event *event)
 	if (!hwc->sample_period)
 		return -EINVAL;
 
+	/*
+	 * If we modify hwc->sample_period, we also need to update
+	 * hwc->last_period and hwc->period_left.
+	 */
+	hwc->last_period = hwc->sample_period;
+	local64_set(&hwc->period_left, hwc->sample_period);
+
 	hwc->config_base = perf_ibs->msr;
 	hwc->config = config;