Messages in this thread | | | From | Linus Torvalds <> | Date | Wed, 12 Feb 2020 10:45:06 -0800 | Subject | Re: [PATCH v8 07/11] proc: flush task dcache entries from all procfs instances |
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On Wed, Feb 12, 2020 at 7:01 AM Eric W. Biederman <ebiederm@xmission.com> wrote: > > Fundamentally proc_flush_task is an optimization. Just getting rid of > dentries earlier. At least at one point it was an important > optimization because the old process dentries would just sit around > doing nothing for anyone.
I'm pretty sure it's still important. It's very easy to generate a _ton_ of dentries with /proc.
> I wonder if instead of invalidating specific dentries we could instead > fire wake up a shrinker and point it at one or more instances of proc.
It shouldn't be the dentries themselves that are a freeing problem. They're being RCU-free'd anyway because of lookup. It's the proc_mounts list that is the problem, isn't it?
So it's just fs_info that needs to be rcu-delayed because it contains that list. Or is there something else?
Linus
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