The patch titled
Subject: buffer: use bdev_getblk() to avoid memory reclaim in readahead path
has been added to the -mm mm-unstable branch. Its filename is
buffer-use-bdev_getblk-to-avoid-memory-reclaim-in-readahead-path.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/buffer-use-bdev_getblk-to-avoid-memory-reclaim-in-readahead-path.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: buffer: use bdev_getblk() to avoid memory reclaim in readahead path
Date: Thu, 14 Sep 2023 16:00:07 +0100
__getblk() adds __GFP_NOFAIL, which is unnecessary for readahead; we're
quite comfortable with the possibility that we may not get a bh back.
Switch to bdev_getblk() which does not include __GFP_NOFAIL.
Link: https://lkml.kernel.org/r/20230914150011.843330-5-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Hui Zhu <teawater@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/buffer.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/fs/buffer.c~buffer-use-bdev_getblk-to-avoid-memory-reclaim-in-readahead-path
+++ a/fs/buffer.c
@@ -1464,7 +1464,9 @@ EXPORT_SYMBOL(__getblk_gfp);
*/
void __breadahead(struct block_device *bdev, sector_t block, unsigned size)
{
- struct buffer_head *bh = __getblk(bdev, block, size);
+ struct buffer_head *bh = bdev_getblk(bdev, block, size,
+ GFP_NOWAIT | __GFP_MOVABLE);
+
if (likely(bh)) {
bh_readahead(bh, REQ_RAHEAD);
brelse(bh);
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-convert-dax-lock-unlock-page-to-lock-unlock-folio.patch
buffer-pass-gfp-flags-to-folio_alloc_buffers.patch
buffer-hoist-gfp-flags-from-grow_dev_page-to-__getblk_gfp.patch
ext4-use-bdev_getblk-to-avoid-memory-reclaim-in-readahead-path.patch
buffer-use-bdev_getblk-to-avoid-memory-reclaim-in-readahead-path.patch
buffer-convert-getblk_unmovable-and-__getblk-to-use-bdev_getblk.patch
buffer-convert-sb_getblk-to-call-__getblk.patch
ext4-call-bdev_getblk-from-sb_getblk_gfp.patch
buffer-remove-__getblk_gfp.patch
