lkml.org 
[lkml]   [2014]   [Feb]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] perf, nmi: fix unknown NMI warning
Date
From: Markus Metzger <markus.t.metzger@intel.com>

[From Markus, just sending for him because he had problems with his mail]

When using BTS on Core i7-4*, I get the below kernel warning.

$ perf record -c 1 -e branches:u ls
Message from syslogd@labpc1501 at Nov 11 15:49:25 ...
kernel:[ 438.317893] Uhhuh. NMI received for unknown reason 31 on CPU 2.

Message from syslogd@labpc1501 at Nov 11 15:49:25 ...
kernel:[ 438.317920] Do you have a strange power saving mode enabled?

Message from syslogd@labpc1501 at Nov 11 15:49:25 ...
kernel:[ 438.317945] Dazed and confused, but trying to continue

Make intel_pmu_handle_irq() take the full exit path when returning early.

Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
arch/x86/kernel/cpu/perf_event_intel.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 0fa4f24..698ae77 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -1361,10 +1361,8 @@ static int intel_pmu_handle_irq(struct pt_regs *regs)
intel_pmu_disable_all();
handled = intel_pmu_drain_bts_buffer();
status = intel_pmu_get_status();
- if (!status) {
- intel_pmu_enable_all(0);
- return handled;
- }
+ if (!status)
+ goto done;

loops = 0;
again:
--
1.8.5.3


\
 
 \ /
  Last update: 2014-02-15 02:21    [W:0.072 / U:0.260 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site