futex: add FUTEX_HAS_TIMEOUT flag to restart.futex.flags
authorDarren Hart <dvhltc@us.ibm.com>
Fri, 3 Apr 2009 20:40:22 +0000 (13:40 -0700)
committerThomas Gleixner <tglx@linutronix.de>
Mon, 6 Apr 2009 09:14:02 +0000 (11:14 +0200)
commita72188d8a64ebe74722f1cf7ffac41b41ffdba21
tree5283404345b270bf5ca95ce8d792baacdf8cf7dc
parent8dac456a681bd94272ff50ecb31be6b669382c2b
futex: add FUTEX_HAS_TIMEOUT flag to restart.futex.flags

Currently restart is only used if there is a timeout. The requeue_pi
functionality requires restarting to futex_lock_pi() on signal after
wakeup in futex_wait_requeue_pi() regardless of if there was a timeout
or not. Using 0 for the timeout value is confusing as that could
indicate an expired timer. The flag makes this explicit. While the
check is not technically needed in futex_wait_restart(), doing so
makes the code consistent with and will avoid confusion should the
need arise to restart wait without a timeout.

Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
kernel/futex.c