Re: [PATCH v2 11/11] zsmalloc: populate new zspage outside class->lock in zs_store()

[Nhat Pham]

On Mon, Nov 9, 2026 at 10:49 PM Sergey Senozhatsky
<senozhatsky@xxxxxxxxxxxx> wrote:
>
> A new zspage is not on class fullness lists and is not movable until
> zs_store() calls insert_zspage() and SetZsPageMovable(), so neither
> other zs_store() callers nor compaction and page migration can see it.
> Nobody else has the handle yet either.
>
> So for a new zspage allocate the object and copy the data before we
> take class->lock, and don't take zspage read lock.  This makes
> class->lock critical section shorter and saves a zspage lock/unlock.
>
> Suggested-by: Yosry Ahmed <yosry@xxxxxxxxxx>
> Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>

Reviewed-by: Nhat Pham <nphamcs@xxxxxxxxx>