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| author |  Chengming Zhou <zhouchengming@bytedance.com>
| 2024-02-04 03:06:00 +0000 |
|---|---|---|
| committer |  Andrew Morton <akpm@linux-foundation.org>
| 2024-02-22 10:24:54 -0800 |
| commit | 0827a1fb143fae588cb6f5b9a97c405d6c2ddec9 (patch) | |
| tree | 76de3ff51d3ad34fbc26d8743134ce1b383d4fd9 /mm/swapfile.c | |
| parent | mm/zswap: add more comments in shrink_memcg_cb() (diff) | |
| download | linux-0827a1fb143fae588cb6f5b9a97c405d6c2ddec9.tar.gz linux-0827a1fb143fae588cb6f5b9a97c405d6c2ddec9.tar.bz2 linux-0827a1fb143fae588cb6f5b9a97c405d6c2ddec9.zip | |
mm/zswap: invalidate zswap entry when swap entry free
During testing I found there are some times the zswap_writeback_entry()
return -ENOMEM, which is not we expected:
bpftrace -e 'kr:zswap_writeback_entry {@[(int32)retval]=count()}'
@[-12]: 1563
@[0]: 277221
The reason is that __read_swap_cache_async() return NULL because
swapcache_prepare() failed. The reason is that we won't invalidate zswap
entry when swap entry freed to the per-cpu pool, these zswap entries are
still on the zswap tree and lru list.
This patch moves the invalidation ahead to when swap entry freed to the
per-cpu pool, since there is no any benefit to leave trashy zswap entry on
the tree and lru list.
With this patch:
bpftrace -e 'kr:zswap_writeback_entry {@[(int32)retval]=count()}'
@[0]: 259744
Note: large folio can't have zswap entry for now, so don't bother
to add zswap entry invalidation in the large folio swap free path.
Link: https://lkml.kernel.org/r/20240201-b4-zswap-invalidate-entry-v2-2-99d4084260a0@bytedance.com
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/swapfile.c')
| -rw-r--r-- | mm/swapfile.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index a8edaf4e5b8a..d1bd8d1e17bd 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -744,7 +744,6 @@ static void swap_range_free(struct swap_info_struct *si, unsigned long offset, swap_slot_free_notify = NULL; while (offset <= end) { arch_swap_invalidate_page(si->type, offset); - zswap_invalidate(si->type, offset); if (swap_slot_free_notify) swap_slot_free_notify(si->bdev, offset); offset++; |