Messages in this thread | | | From | Nhat Pham <> | Date | Tue, 26 Mar 2024 14:49:30 -0700 | Subject | Re: [RFC PATCH 1/9] mm: zswap: always shrink in zswap_store() if zswap_pool_reached_full |
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On Mon, Mar 25, 2024 at 4:50 PM Yosry Ahmed <yosryahmed@google.com> wrote: > > The cleanup code in zswap_store() is not pretty, particularly the > 'shrink' label at the bottom that ends up jumping between cleanup > labels. > > Instead of having a dedicated label to shrink the pool, just use > zswap_pool_reached_full directly to figure out if the pool needs > shrinking. zswap_pool_reached_full should be true if and only if the > pool needs shrinking. > > The only caveat is that the value of zswap_pool_reached_full may be > changed by concurrent zswap_store() calls between checking the limit and > testing zswap_pool_reached_full in the cleanup code. This is fine > because: > - If zswap_pool_reached_full was true during limit checking then became > false during the cleanup code, then someone else already took care of > shrinking the pool and there is no need to queue the worker. That > would be a good change.
Yup.
> - If zswap_pool_reached_full was false during limit checking then became > true during the cleanup code, then someone else hit the limit > meanwhile. In this case, both threads will try to queue the worker, > but it never gets queued more than once anyway. Also, calling > queue_work() multiple times when the limit is hit could already happen > today, so this isn't a significant change in any way.
Agree.
> > Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
This change by itself seems fine to me. Reviewed-by: Nhat Pham <nphamcs@gmail.com>
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