Messages in this thread |  | | Date | Thu, 21 Sep 2017 08:31:34 -0700 | From | "Paul E. McKenney" <> | Subject | Re: Query regarding synchronize_sched_expedited and resched_cpu |
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On Thu, Sep 21, 2017 at 03:55:46PM +0200, Peter Zijlstra wrote: > On Mon, Sep 18, 2017 at 11:11:05AM -0400, Steven Rostedt wrote: > > On Sun, 17 Sep 2017 11:37:06 +0530 > > Neeraj Upadhyay <neeraju@codeaurora.org> wrote: > > > > > Hi Paul, how about replacing raw_spin_trylock_irqsave with > > > raw_spin_lock_irqsave in resched_cpu()? Are there any paths > > > in RCU code, which depend on trylock check/spinlock recursion? > > > > It looks to me that resched_cpu() was added for nohz full sched > > balancing, but is not longer used by that. The only user is currently > > RCU. Perhaps we should change that from a trylock to a lock. > > No, regular NOHZ balancing. NOHZ FULL wasn't conceived back then. > > 46cb4b7c88fa ("sched: dynticks idle load balancing") > > And yeah, its no longer used for that. > > And given RCU is the only user of that thing, I suppose we can indeed > change it to a full lock.
Thank you! May I have your ack?
Thanx, Paul
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