Re: [PATCH v5 0/6] fs/dcache: Track & limit # of negative dentries

From: Waiman Long
Date: Mon Jul 02 2018 - 20:46:37 EST


On 07/03/2018 03:34 AM, Linus Torvalds wrote:
> On Sun, Jul 1, 2018 at 10:52 PM Waiman Long <longman@xxxxxxxxxx> 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