Re: [PATCH v2 0/2] mm/zswap: Fixes and improves the zswap global shrinker

[Hao Jia <jiahao.kernel@gmail.com>]

On 2026/7/23 12:49, Yosry Ahmed wrote:
> On Wed, Jul 22, 2026 at 6:21 PM Hao Jia <jiahao.kernel@gmail.com> wrote:
>>
>>
>>
>> On 2026/7/20 09:26, Hao Jia wrote:
>>>
>>>
>>> On 2026/7/18 12:40, Andrew Morton wrote:
>>>> On Fri, 17 Jul 2026 18:28:04 -0700 Yosry Ahmed <yosry@kernel.org> wrote:
>>>>
>>>>>>
>>>>>> The [1/2] changelog lacks a description of how the flaw impacts users.
>>>>>> Please describe this fully and maintain that info within the
>>>>>> changelogging.  This info helps -stable maintainers and others
>>>>>> understand why we're proposing a backport and helps myself and others
>>>>>> with timing decisions.
>>>>>
>>>>> The first line in the changelog should be sufficient imo: "Zswap
>>>>> writeback on hitting the pool limit is broken when memory cgroup is
>>>>> disabled"
>>>>
>>>> "broken"?  Perhaps this means "fails to occur".
>>>>
>>>> But what is the userspace-visible impact?  IOW, why are we proposing a
>>>> backport?
>>>>
>>>
>>> Perhaps the first paragraph of the commit1 message could be modified as
>>> follows? I have added a description of the issues that occur without
>>> this patch.
>>>
>>
>> Hi Andrew, Yosry, and Nhat,
>> Any thoughts on this change?
> 
> I would front load the user impact in the first paragraph:
> 
> Zswap writeback when the global pool limit is hit fails when memory
> cgroups are disabled. The pool remains full until it is organically
> drained by swapins or memory freeing, leading to zswap store failures
> and pages bypassing getting written directly to the backing swap device,
> causing LRU inversion (hotter pages with higher fault latency).
> 
> ...

Will done.

Thanks,
Hao