]> git.baikalelectronics.ru Git - kernel.git/commit
rcu: Allow RCU quiescent-state forcing to be preempted
authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Mon, 25 Jun 2012 15:41:11 +0000 (08:41 -0700)
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Sun, 23 Sep 2012 14:41:54 +0000 (07:41 -0700)
commit3039df22a043e228244090cfb4cbcd21e64899dc
tree5eb8367be67bde57671240bfeb149c4c670ffd1c
parent7e56b348dba1c2c05ea9251a244bee669881aa6f
rcu: Allow RCU quiescent-state forcing to be preempted

RCU quiescent-state forcing is currently carried out without preemption
points, which can result in excessive latency spikes on large systems
(many hundreds or thousands of CPUs).  This patch therefore inserts
a voluntary preemption point into force_qs_rnp(), which should greatly
reduce the magnitude of these spikes.

Reported-by: Mike Galbraith <mgalbraith@suse.de>
Reported-by: Dimitri Sivanich <sivanich@sgi.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
kernel/rcutree.c