Re: [regression] 5.15 kernel triggering 100x more inode evictions

[Thorsten Leemhuis <regressions@leemhuis.info>]

On 09.04.22 19:12, Bruno Damasceno Freire wrote:
> On 08.04.22 04:50, Thorsten Leemhuis wrote:
>> First off: David, Filipe, many thx for your answers, that helped me a
>> lot to get a better picture of the situation!
>> On 08.04.22 17:55, Filipe Manana wrote:
>>> On Fri, Apr 08, 2022 at 04:52:22PM +0200, David Sterba wrote:
>>>> On Fri, Apr 08, 2022 at 12:32:20PM +0200, Thorsten Leemhuis wrote:
>
>>> [...]
>>
>>> 6) In short, it is not known what causes the excessive evictions on 5.15
>>>    on his machine for that specific workload - we don't have a commit to
>>>    point at and say it caused a regression. [...]
>>
>> Bruno, under these circumstances I'd say you need to bisect this to get
>> us closer to the root of the problem (and a fix for it). Sadly that how
>> it is sometimes, as briefly explained here:
>>
>> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/Documentation/admin-guide/reporting-regressions.rst#n140
> 
> Ok Thorsten.
> 
> It's not sad at all: I had a great time researching this regression and
> gained a lot of knowledge while doing so. The problem is that I am just a
> simple user at its limits here and additional bisection is probably beyond my
> abilities.

Maybe, but I think you underestimate yourself here. Give it a try, it's
not that hard once you figured out how to build and install a vanilla
kernel (which you did already afaics; and if not: it's not that hard and
you learn new stuff, too) and have some test case to check if the
problem is there or now (which you already have afaics).

Ciao, Thorsten