github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-09-12 20:53:03 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

mm/swap: revert to single-folio writes for synchronous swap devices

Browse Source 
Patch series "swap_ops updates", v2.

This series is a follow on to the swap ops series now in mm-unstable.

The first patch reintroduces direct folio writes for synchronous
swap files, the other two remove the double indirect for file
system based swap.


This patch (of 3):

Kairui Song reported that zram benefits from submitting each folio
directly instead of batching up I/O because the classic LRU scanning
benefits from clearing the folio writeback bit in the scan loop.

Accommodate that by kicking off writes for synchronous devices for each
iteration.

Link: https://lore.kernel.org/20260723054622.3460249-1-hch@lst.de
Link: https://lore.kernel.org/20260723054622.3460249-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Usama Arif <usama.arif@linux.dev>
Acked-by: Chris Li <chrisl@kernel.org>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Steve French <sfrench@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Christoph Hellwig 2026-07-23 07:46:04 +02:00 committed by Andrew Morton
parent f7bf5cd5b5
commit 3c5194eb2e
1 changed files with 10 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
mm/page_io.c
View File

@ -358,7 +358,16 @@ static void swap_add_folio(struct swap_io_ctx *ctx, struct folio *folio, int rw)
}
bvec_set_folio(&sio->bvecs[sio->nr_bvecs], folio, folio_size(folio), 0);
sio->len += folio_size(folio);
if (++sio->nr_bvecs == ARRAY_SIZE(sio->bvecs)) {
/*
* Write out the iocb if we filled it, or if the device is synchronous.
*
* The latter is to work around expectations in the classic LRU code
* which make synchronous clearing of the folio writeback flag in the
* reclaim path beneficial.
*/
if (++sio->nr_bvecs == ARRAY_SIZE(sio->bvecs) ||
(rw == WRITE && (sis->flags & SWP_SYNCHRONOUS_IO))) {
if (rw == WRITE)
swap_write_submit(ctx);
else