From: Konstantin Khorenko <khorenko@virtuozzo.com>
To: Alexey Kuznetsov <kuznet@virtuozzo.com>,
devel@openvz.org, Konstantin Khorenko <khorenko@virtuozzo.com>
Subject: [Devel] [PATCH hci-8.1 1/2] Revert "fs/ext4: do not run test_and_set_bit on every prefetch scan"
Date: Tue, 22 Sep 2026 15:27:47 +0200 [thread overview]
Message-ID: <20260922-pr-khorenko-vstor-145663-ext4-ms-v1-1-4dd83d495810@virtuozzo.com> (raw)
In-Reply-To: <20260922-pr-khorenko-vstor-145663-ext4-ms-v1-0-4dd83d495810@virtuozzo.com>
This reverts commit 3fff8724d1f894459c1477990fe086c0c2573410.
Mainstream has already fixed this issue the same way, only with the
test_bit check folded into the macro instead of the call site, so drop
our patch and take the mainstream version:
0e364a030229b ("ext4: avoid RWM atomic in EXT4_MB_GRP_TEST_AND_SET_READ")
https://virtuozzo.atlassian.net/browse/VSTOR-137147
https://virtuozzo.atlassian.net/browse/VSTOR-145663
Feature: fix ms/ext4
Signed-off-by: Konstantin Khorenko <khorenko@virtuozzo.com>
---
fs/ext4/ext4.h | 2 --
fs/ext4/mballoc.c | 4 +---
2 files changed, 1 insertion(+), 5 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index ca6498609e2e1..bf7637785e073 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -3514,8 +3514,6 @@ struct ext4_group_info {
(clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
#define EXT4_MB_GRP_TEST_AND_SET_READ(grp) \
(test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_READ_BIT, &((grp)->bb_state)))
-#define EXT4_MB_GRP_TEST_READ(grp) \
- (test_bit(EXT4_GROUP_INFO_BBITMAP_READ_BIT, &((grp)->bb_state)))
#define EXT4_MAX_CONTENTION 8
#define EXT4_CONTENTION_THRESHOLD 2
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index b50aa34057967..aaf2c24c514c6 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2836,9 +2836,7 @@ ext4_group_t ext4_mb_prefetch(struct super_block *sb, ext4_group_t group,
* prefetch once, so we avoid getblk() call, which can
* be expensive.
*/
- if (gdp && grp &&
- !EXT4_MB_GRP_TEST_READ(grp) &&
- !EXT4_MB_GRP_TEST_AND_SET_READ(grp) &&
+ if (gdp && grp && !EXT4_MB_GRP_TEST_AND_SET_READ(grp) &&
EXT4_MB_GRP_NEED_INIT(grp) &&
ext4_free_group_clusters(sb, gdp) > 0 ) {
bh = ext4_read_block_bitmap_nowait(sb, group, true);
--
2.43.0
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next prev parent reply other threads:[~2026-09-22 13:29 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-22 13:27 [Devel] [PATCH hci-8.1 0/2] ext4: replace the vz prefetch test_bit patch with the mainstream one Konstantin Khorenko
2026-09-22 13:27 ` Konstantin Khorenko [this message]
2026-09-22 13:27 ` [Devel] [PATCH hci-8.1 2/2] ext4: avoid RWM atomic in EXT4_MB_GRP_TEST_AND_SET_READ Konstantin Khorenko
2026-09-22 13:31 ` [Devel] [PATCH hci-8.1 0/2] ext4: replace the vz prefetch test_bit patch with the mainstream one Konstantin Khorenko
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