From c75841a398d667d9968245b9519d93cedbfb4780 Mon Sep 17 00:00:00 2001
From: Robert Richter <robert.richter@amd.com>
Date: Mon, 2 Apr 2012 20:19:07 +0200
Subject: [PATCH] perf/x86-ibs: Fix update of period
The last sw period was not correctly updated on overflow and thus led
to wrong distribution of events. We always need to properly initialize
data.period in struct perf_sample_data.
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1333390758-10893-2-git-send-email-robert.richter@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/cpu/perf_event_amd_ibs.c | 27 ++++++++++++------------
1 file changed, 14 insertions(+), 13 deletions(-)
diff --git a/arch/x86/kernel/cpu/perf_event_amd_ibs.c b/arch/x86/kernel/cpu/perf_event_amd_ibs.c
index 8ff74d439041..c8f69bea6624 100644
--- a/arch/x86/kernel/cpu/perf_event_amd_ibs.c
+++ b/arch/x86/kernel/cpu/perf_event_amd_ibs.c
@@ -386,7 +386,21 @@ static int perf_ibs_handle_irq(struct perf_ibs *perf_ibs, struct pt_regs *iregs)
if (!(*buf++ & perf_ibs->valid_mask))
return 0;
+ /*
+ * Emulate IbsOpCurCnt in MSRC001_1033 (IbsOpCtl), not
+ * supported in all cpus. As this triggered an interrupt, we
+ * set the current count to the max count.
+ */
+ config = ibs_data.regs[0];
+ if (perf_ibs == &perf_ibs_op && !(ibs_caps & IBS_CAPS_RDWROPCNT)) {
+ config &= ~IBS_OP_CUR_CNT;
+ config |= (config & IBS_OP_MAX_CNT) << 36;
+ }
+
+ perf_ibs_event_update(perf_ibs, event, config);
perf_sample_data_init(&data, 0);
+ data.period = event->hw.last_period;
+
if (event->attr.sample_type & PERF_SAMPLE_RAW) {
ibs_data.caps = ibs_caps;
size = 1;
@@ -405,19 +419,6 @@ static int perf_ibs_handle_irq(struct perf_ibs *perf_ibs, struct pt_regs *iregs)
regs = *iregs; /* XXX: update ip from ibs sample */
- /*
- * Emulate IbsOpCurCnt in MSRC001_1033 (IbsOpCtl), not
- * supported in all cpus. As this triggered an interrupt, we
- * set the current count to the max count.
- */
- config = ibs_data.regs[0];
- if (perf_ibs == &perf_ibs_op && !(ibs_caps & IBS_CAPS_RDWROPCNT)) {
- config &= ~IBS_OP_CUR_CNT;
- config |= (config & IBS_OP_MAX_CNT) << 36;
- }
-
- perf_ibs_event_update(perf_ibs, event, config);
-
overflow = perf_ibs_set_period(perf_ibs, hwc, &config);
reenable = !(overflow && perf_event_overflow(event, &data, ®s));
config = (config >> 4) | (reenable ? perf_ibs->enable_mask : 0);
--
GitLab