lkml.org 
[lkml]   [2009]   [May]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:perfcounters/core] perf_counter: fix nmi-watchdog interaction
Commit-ID:  63a809a2dc53b91268dd915bbcbd425063893676
Gitweb: http://git.kernel.org/tip/63a809a2dc53b91268dd915bbcbd425063893676
Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Fri, 1 May 2009 12:23:17 +0200
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Fri, 1 May 2009 13:23:44 +0200

perf_counter: fix nmi-watchdog interaction

When we don't have any perf-counters active, don't act like we know
what the NMI is for.

[ Impact: fix hard hang with nmi_watchdog=2 ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090501102533.109867793@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>


---
arch/x86/kernel/cpu/perf_counter.c | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c
index fc06f4d..d4c0cc9 100644
--- a/arch/x86/kernel/cpu/perf_counter.c
+++ b/arch/x86/kernel/cpu/perf_counter.c
@@ -871,6 +871,9 @@ perf_counter_nmi_handler(struct notifier_block *self,
struct pt_regs *regs;
int ret;

+ if (!atomic_read(&num_counters))
+ return NOTIFY_DONE;
+
switch (cmd) {
case DIE_NMI:
case DIE_NMI_IPI:

\
 
 \ /
  Last update: 2009-05-01 15:31    [from the cache]
©2003-2011 Jasper Spaans