tree 250fc4f3d02c58eddf770e9d040edeafd0012e76
parent 1123d93963cbd2546449d4d9f0c568e323cb0ac6
author Thomas Gleixner <tglx@linutronix.de> 1308234128 +0200
committer Thomas Gleixner <tglx@linutronix.de> 1308245453 +0200

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