Re: [PATCH v1 11/26] mm: page_io: prevent memory cgroup release in page_io module

Qi Zheng
2025-11-20T13:34:28Z

On 11/19/25 5:26 PM, Harry Yoo wrote:
> On Tue, Oct 28, 2025 at 09:58:24PM +0800, Qi Zheng wrote:
>> From: Muchun Song <songmuchun@bytedance.com>
>>
>> In the near future, a folio will no longer pin its corresponding
>> memory cgroup. To ensure safety, it will only be appropriate to
>> hold the rcu read lock or acquire a reference to the memory cgroup
>> returned by folio_memcg(), thereby preventing it from being released.
>>
>> In the current patch, the rcu read lock is employed to safeguard
>> against the release of the memory cgroup in swap_writepage() and
>
> nit: ^ swap_writeout()

will fix it.

>
>> bio_associate_blkg_from_page().
>>
>> This serves as a preparatory measure for the reparenting of the
>> LRU pages.
>>
>> Signed-off-by: Muchun Song <songmuchun@bytedance.com>
>> Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
>> ---
>
> Looks good to me,
> Reviewed-by: Harry Yoo <harry.yoo@oracle.com>

Thanks!

>