Re: [PATCH] mm/zswap: reduce the size of the compression buffer to a single page

[SeongJae Park <sj@kernel.org>]

On Wed, 20 Aug 2025 11:15:47 -0700 Nhat Pham <nphamcs@gmail.com> wrote:

> Reduce the compression buffer size from 2 * PAGE_SIZE to only one page,
> as the compression output (in the success case) should not exceed the
> length of the input.
> 
> In the past, Chengming tried to reduce the compression buffer size, but
> ran into issues with the LZO algorithm (see [2]). Herbert Xu reported
> that the issue has been fixed (see [3]). Now we should have the
> guarantee that compressors' output should not exceed one page in the
> success case, and the algorithm will just report failure otherwise.
> 
> With this patch, we save one page per cpu (per compression algorithm).
> 
> [1]: https://lore.kernel.org/linux-mm/20231213-zswap-dstmem-v4-1-f228b059dd89@bytedance.com/

This is not mentioned anywhere.  Probably you added this as a reference for the
past work from Chengming?

> [2]: https://lore.kernel.org/lkml/0000000000000b05cd060d6b5511@google.com/
> [3]: https://lore.kernel.org/linux-mm/aKUmyl5gUFCdXGn-@gondor.apana.org.au/
> 
> Co-developed-by: Chengming Zhou <chengming.zhou@linux.dev>
> Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev>
> Signed-off-by: Nhat Pham <nphamcs@gmail.com>

Acked-by: SeongJae Park <sj@kernel.org>

[...]


Thanks,
SJ