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From: Chengming Zhou In-Reply-To: <20260202-zswap-syncio-cleanup-v1-1-86bb24a64521@tencent.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 62C9C180002 X-Stat-Signature: e993wr6u8jdspa7wbdwm84mcsyif3gxd X-HE-Tag: 1770101509-773598 X-HE-Meta: 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 fbLF0Ka2 bMcIXC7pewL+Q/h6z9xys2vjf9rGN+d6cKXmQP8V8mEcrGzqT3g8Y8zPgeEg4eO5F8dXAUwFr/TilBuY3qKCRX5nbU7EeAWg1K5U+m4UL82mjKTOlqx6kp2xtpYVpVWLFUDE+nWHGnH4e34zwyWLi21okCMA2vj/EHooa1+RXweDNj7Rk7y4Pw4HwIzMtGPMLeT/vrQhGc4TzpbM5w+Hg+nnR/Z5KDQ5/rTYXswvCiNY2m3cLGxzT1+pUlUsYJz66GktgiXwyp4jbcOLPdYNYjIiihxTi1jBnVfwzlnUjBc6Cvk0e9JXyYOf/k1L/euHxspq5 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 2026/2/2 01:47, Kairui Song wrote: > From: Kairui Song > > Since commit f1879e8a0c60 ("mm, swap: never bypass the swap cache even > for SWP_SYNCHRONOUS_IO"), all swap-in operations go through the swap > cache, including those from SWP_SYNCHRONOUS_IO devices like > zram. Which means the workaround for swap cache bypassing > introduced by commit 25cd241408a2 ("mm: zswap: fix data loss on > SWP_SYNCHRONOUS_IO devices") is no longer needed. Remove it, but > keep the comments that are still helpful. > > Suggested-by: Yosry Ahmed > Signed-off-by: Kairui Song Reviewed-by: Chengming Zhou Thanks! > --- > mm/zswap.c | 19 ++++++------------- > 1 file changed, 6 insertions(+), 13 deletions(-) > > diff --git a/mm/zswap.c b/mm/zswap.c > index 3d2d59ac3f9c..8cd61603ff79 100644 > --- a/mm/zswap.c > +++ b/mm/zswap.c > @@ -1589,11 +1589,11 @@ int zswap_load(struct folio *folio) > { > swp_entry_t swp = folio->swap; > pgoff_t offset = swp_offset(swp); > - bool swapcache = folio_test_swapcache(folio); > struct xarray *tree = swap_zswap_tree(swp); > struct zswap_entry *entry; > > VM_WARN_ON_ONCE(!folio_test_locked(folio)); > + VM_WARN_ON_ONCE(!folio_test_swapcache(folio)); > > if (zswap_never_enabled()) > return -ENOENT; > @@ -1624,22 +1624,15 @@ int zswap_load(struct folio *folio) > count_objcg_events(entry->objcg, ZSWPIN, 1); > > /* > - * When reading into the swapcache, invalidate our entry. The > - * swapcache can be the authoritative owner of the page and > + * We are reading into the swapcache, invalidate zswap entry. > + * The swapcache is the authoritative owner of the page and > * its mappings, and the pressure that results from having two > * in-memory copies outweighs any benefits of caching the > * compression work. > - * > - * (Most swapins go through the swapcache. The notable > - * exception is the singleton fault on SWP_SYNCHRONOUS_IO > - * files, which reads into a private page and may free it if > - * the fault fails. We remain the primary owner of the entry.) > */ > - if (swapcache) { > - folio_mark_dirty(folio); > - xa_erase(tree, offset); > - zswap_entry_free(entry); > - } > + folio_mark_dirty(folio); > + xa_erase(tree, offset); > + zswap_entry_free(entry); > > folio_unlock(folio); > return 0; > > --- > base-commit: 2c263046cbe6d9d5fce3dfeba063f199f7e6298f > change-id: 20251226-zswap-syncio-cleanup-a05b7fc6180f > > Best regards,