diff options
| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-06-21 23:51:21 +0530 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2017-04-11 10:59:13 +0200 |
| commit | 41e1172898c515ada8580bbaec7713253cfaa241 (patch) | |
| tree | e17356e38473042b861c990d3b488fdc813b7d29 /kernel | |
| parent | fca2abec4b53f41142fa7f147b050bd27fcaa7ef (diff) | |
rcu: Avoid redundant grace-period kthread wakeups
When setting up an in-the-future "advanced" grace period, the code needs
to wake up the relevant grace-period kthread, which it currently does
unconditionally. However, this results in needless wakeups in the case
where the advanced grace period is being set up by the grace-period
kthread itself, which is a non-uncommon situation. This commit therefore
checks to see if the running thread is the grace-period kthread, and
avoids doing the irq_work_queue()-mediated wakeup in that case.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Git-commit: 1eafd31c640d6799c63136246a59d608bed93c74
[kishank@codeaurora.org resolve trivial conflicts]
Signed-off-by: Kishan Kumar <kishank@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Change-Id: I1fdcf6664fdc7dce188488f05f33931e3614c853
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcutree.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 20026ec30..6c0c5ede0 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -1590,10 +1590,12 @@ rcu_start_gp_advanced(struct rcu_state *rsp, struct rcu_node *rnp, /* * We can't do wakeups while holding the rnp->lock, as that - * could cause possible deadlocks with the rq->lock. Deter - * the wakeup to interrupt context. + * could cause possible deadlocks with the rq->lock. Defer + * the wakeup to interrupt context. And don't bother waking + * up the running kthread. */ - irq_work_queue(&rsp->wakeup_work); + if (current != rsp->gp_kthread) + irq_work_queue(&rsp->wakeup_work); } /* |