Re: [PATCH v2 0/4] mm/zswap: Implement per-cgroup proactive writeback

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

On 2026/5/26 03:24, Andrew Morton wrote:
> On Mon, 25 May 2026 20:22:38 +0800 Hao Jia <jiahao.kernel@gmail.com> wrote:
> 
>> Zswap currently writes back pages to backing swap reactively, triggered
>> either by the shrinker or by the pool reaching its size limit. Although
>> proactive memory reclaim can automatically write back a portion of zswap
>> pages via the shrinker, it cannot explicitly control the amount of
>> writeback for a specific memory cgroup. Moreover, proactive memory reclaim
>> may not always be triggered during a steady state.
>>
>> In certain scenarios, it is desirable to trigger writeback in advance to
>> free up memory. For example, users may want to prepare for an upcoming
>> memory-intensive workload by flushing cold memory to the backing storage
>> when the system is relatively idle.
>>
>> This patch series introduces a "zswap_writeback_only" key to memory.reclaim
>> cgroup interface, allowing users to proactively write back cold compressed
>> pages from zswap to the backing swap device. When specified, this key
>> bypasses standard memory reclaim and exclusively performs proactive zswap
>> writeback up to the requested budget. If omitted, the default reclaim
>> behavior remains unchanged.
> 
> Thanks.  AI review found a few things to complain about, one of them
> described as "preexisting".
> 

Thanks Andrew.  I have replied to the AI's review comments in a separate 
email and posted v3.
https://lore.kernel.org/all/20260526114601.67041-1-jiahao.kernel@gmail.com

Thanks,
Hao