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authorThomas Gleixner <tglx@linutronix.de>2011-06-16 16:22:08 +0200
committerThomas Gleixner <tglx@linutronix.de>2011-06-16 19:30:53 +0200
commitb5199515c25cca622495eb9c6a8a1d275e775088 (patch)
tree250fc4f3d02c58eddf770e9d040edeafd0012e76 /include
parent1123d93963cbd2546449d4d9f0c568e323cb0ac6 (diff)
downloadlinux-b5199515c25cca622495eb9c6a8a1d275e775088.tar.bz2
clocksource: Make watchdog robust vs. interruption
The clocksource watchdog code is interruptible and it has been observed that this can trigger false positives which disable the TSC. The reason is that an interrupt storm or a long running interrupt handler between the read of the watchdog source and the read of the TSC brings the two far enough apart that the delta is larger than the unstable treshold. Move both reads into a short interrupt disabled region to avoid that. Reported-and-tested-by: Vernon Mauery <vernux@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org
Diffstat (limited to 'include')
-rw-r--r--include/linux/clocksource.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index d4646b48dc4a..18a1baf31f2d 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -188,6 +188,7 @@ struct clocksource {
#ifdef CONFIG_CLOCKSOURCE_WATCHDOG
/* Watchdog related data, used by the framework */
struct list_head wd_list;
+ cycle_t cs_last;
cycle_t wd_last;
#endif
} ____cacheline_aligned;