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Subject: Re: [PATCH v5 0/6] fs/dcache: Track & limit # of negative dentries
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
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From: Waiman Long <longman@redhat.com>
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Date: Tue, 3 Jul 2018 08:46:07 +0800
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On 07/03/2018 03:34 AM, Linus Torvalds wrote:
> On Sun, Jul 1, 2018 at 10:52 PM Waiman Long <longman@redhat.com> wrote:
>> A rogue application can potentially create a large number of negative
>> dentries in the system consuming most of the memory available if it
>> is not under the direct control of a memory controller that enforce
>> kernel memory limit.
> I certainly don't mind the patch series, but I would like it to be
> accompanied with some actual example numbers, just to make it all a
> bit more concrete.
>
> Maybe even performance numbers showing "look, I've filled the dentry
> lists with nasty negative dentries, now it's all slower because we
> walk those less interesting entries".
>
>               Linus

I did have performance numbers in the previous version of the patchset.
I will rerun the performance test and post the numbers later on.

Cheers,
Longman