mm/zswap: zswap entry doesn't need refcount anymore

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Since we don't need to leave zswap entry on the zswap tree anymore,
we should remove it from tree once we find it from the tree.

Then after using it, we can directly free it, no concurrent path
can find it from tree. Only the shrinker can see it from lru list,
which will also double check under tree lock, so no race problem.

So we don't need refcount in zswap entry anymore and don't need to
take the spinlock for the second time to invalidate it.

The side effect is that zswap_entry_free() maybe not happen in tree
spinlock, but it's ok since nothing need to be protected by the lock.

Link: https://lkml.kernel.org/r/20240201-b4-zswap-invalidate-entry-v2-6-99d4084260a0@bytedance.com
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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This commit is contained in:

Chengming Zhou 2024-02-04 03:06:04 +00:00 • committed by Andrew Morton

parent c2e2ba7702

commit a230c20e63

1 changed files with 11 additions and 52 deletions

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mm/zswap.c

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