Messages in this thread | | | Date | Sat, 10 Sep 2016 08:17:13 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH] fs/dcache: resched/chill only if we make no progress |
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On Thu, 8 Sep 2016, Sebastian Andrzej Siewior wrote: > + if (parent == dentry) { > + /* the task with the highest priority won't schedule */ > + r = cond_resched(); > + if (!r && (rt_task(current) || dl_task(current)))
That's wrong because a non RT task will just spin until its time slice is up. Wasted cycles for nothing.
Ideally we make spinning conditional on
!on_cpu(dentry->lock->owner)
That would avoid going to sleep if the owner runs on another cpu. We have no mechanism for that, but I think it'd be worth to think about one.
> + cpu_chill(); > + } else > + dentry = parent;
Missing braces
Thanks,
tglx
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