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| author | Kemeng Shi <shikemeng@huaweicloud.com> | 2025-05-22 20:25:51 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-08-15 12:17:07 +0200 |
| commit | 91ffc47baa39dd969ddfd1da2b8a3934c1d352e3 (patch) | |
| tree | 94de9ee4b82b0266bb3abd2324d9dc70106c9016 | |
| parent | 9b01ada580ee84fb319e7ecb5fb5b1f54a9eb799 (diff) | |
mm: swap: move nr_swap_pages counter decrement from folio_alloc_swap() to swap_range_alloc()
commit 4f78252da887ee7e9d1875dd6e07d9baa936c04f upstream.
Patch series "Some randome fixes and cleanups to swapfile".
Patch 0-3 are some random fixes. Patch 4 is a cleanup. More details can
be found in respective patches.
This patch (of 4):
When folio_alloc_swap() encounters a failure in either
mem_cgroup_try_charge_swap() or add_to_swap_cache(), nr_swap_pages counter
is not decremented for allocated entry. However, the following
put_swap_folio() will increase nr_swap_pages counter unpairly and lead to
an imbalance.
Move nr_swap_pages decrement from folio_alloc_swap() to swap_range_alloc()
to pair the nr_swap_pages counting.
Link: https://lkml.kernel.org/r/20250522122554.12209-1-shikemeng@huaweicloud.com
Link: https://lkml.kernel.org/r/20250522122554.12209-2-shikemeng@huaweicloud.com
Fixes: 0ff67f990bd4 ("mm, swap: remove swap slot cache")
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Kairui Song <kasong@tencent.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | mm/swapfile.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index b3feeea2a15b..626fcb9e79e3 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1115,6 +1115,7 @@ static void swap_range_alloc(struct swap_info_struct *si, if (vm_swap_full()) schedule_work(&si->reclaim_work); } + atomic_long_sub(nr_entries, &nr_swap_pages); } static void swap_range_free(struct swap_info_struct *si, unsigned long offset, @@ -1313,7 +1314,6 @@ int folio_alloc_swap(struct folio *folio, gfp_t gfp) if (add_to_swap_cache(folio, entry, gfp | __GFP_NOMEMALLOC, NULL)) goto out_free; - atomic_long_sub(size, &nr_swap_pages); return 0; out_free: |