Re: amusing SLUB compaction bug when CC_OPTIMIZE_FOR_SIZE

Joel Fernandes
2022-09-28T19:53:18Z

> On Sep 28, 2022, at 1:56 PM, Hyeonggon Yoo <42.hyeyoo@gmail.com> wrote:
>
> ﻿On Wed, Sep 28, 2022 at 06:20:10PM +0200, Vlastimil Babka wrote:
[..]
>>>> Thank you for report!
>>>>
>>>> That should be due to commit 65505d1f2338e7
>>>> ("mm/sl[au]b: rearrange struct slab fields to allow larger rcu_head")
>>>> as now rcu_head can use some bits that shares with mapping.
>>>>
>>>> Hmm IMO we have two choices...
>>>>
>>>> 1. simply drop the commit as it's only for debugging (RCU folks may not like [1])
>>>
>>> Yeah definitely don't like this option as patches are out that depend on
>>> this (not yet merged though). :-)
>>
>> But we'll have to do that for now and postpone to 6.2 I'm afraid as merge
>> window for 6.1 is too close to have confidence in any solution that we came
>> up this moment.

I am ok with your postponing till then, gives me time to get other patches in, in the mean while :-)

Thanks again for your work on this,

- Joel