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authorAndi Kleen <ak@suse.de>2007-07-22 13:12:39 +0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-22 22:03:38 +0400
commit57c22f49e4c7d27a03e109a317c30b12f1bae0b2 (patch)
tree093eb013114e2906cca0f7b6524c0b506adf5833
parentf25f64ed5bd3c2932493681bdfdb483ea707da0a (diff)
downloadlinux-57c22f49e4c7d27a03e109a317c30b12f1bae0b2.tar.xz
i386: Handle P6s without performance counters in nmi watchdog
I got an oops while booting a 32bit kernel on KVM because it doesn't implement performance counters used by the NMI watchdog. Handle this case. Cc: Avi Kivity <avi@qumranet.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/i386/kernel/cpu/perfctr-watchdog.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/i386/kernel/cpu/perfctr-watchdog.c b/arch/i386/kernel/cpu/perfctr-watchdog.c
index 30b5e48aa76b..572900398def 100644
--- a/arch/i386/kernel/cpu/perfctr-watchdog.c
+++ b/arch/i386/kernel/cpu/perfctr-watchdog.c
@@ -346,7 +346,9 @@ static int setup_p6_watchdog(unsigned nmi_hz)
perfctr_msr = MSR_P6_PERFCTR0;
evntsel_msr = MSR_P6_EVNTSEL0;
- wrmsrl(perfctr_msr, 0UL);
+ /* KVM doesn't implement this MSR */
+ if (wrmsr_safe(perfctr_msr, 0, 0) < 0)
+ return 0;
evntsel = P6_EVNTSEL_INT
| P6_EVNTSEL_OS