Re: [PATCH 0/2] fs/dcache: Track # of negative dentries

From: Waiman Long
Date: Tue Aug 28 2018 - 18:54:49 EST


On 08/28/2018 06:50 PM, Andrew Morton wrote:
> On Tue, 28 Aug 2018 13:19:38 -0400 Waiman Long <longman@xxxxxxxxxx> wrote:
>
>> This patchset is a reduced scope version of the
>> patchset "fs/dcache: Track & limit # of negative dentries"
>> (https://lkml.org/lkml/2018/7/12/586). Only the first 2 patches are
>> included to track the number of negative dentries in the system as well
>> as making negative dentries more easily reclaimed than positive ones.
>>
>> There are controversies on limiting number of negative dentries as it may
>> make negative dentries special in term of how memory resources are to
>> be managed in the kernel. However, I don't believe I heard any concern
>> about tracking the number of negative dentries in the system. So it is
>> better to separate that out and get it done with. We can deal with the
>> controversial part later on.
> Seems reasonable.
>
> It would be nice to see testing results please. Quite comprehensive
> ones.
>
> And again, an apparently permanent feature of this patchset is that the
> changelogs fail to provide descriptions of real-world problems with the
> existing code. Please do provide those (comprehensive) descriptions and
> demonstrate that these changes resolve those problems.
>
> Also, a grumpynit: with 100% uniformity, the vfs presently refers to
> negative dentries with the string "negative" in the identifier. This
> patchset abbreviates that to "neg".
>
Will do.

Cheers,
Longman