From: Jonas Zhou In the tested x86-64 layout, s_journal and s_ext4_flags share a cache line with s_orphan_lock and s_orphan. Legacy orphan-list updates invalidate the same line used by unrelated journal and inode paths. Move s_orphan_lock, s_orphan and s_orphan_info together below s_journal_triggers. This separates orphan-list writes from journal and flag readers while keeping the related fields in logical groups. Add a comment identifying the orphan tracking group and preserve the existing member comments. On a system with two Xeon Silver 4208 processors and a filesystem without orphan_file enabled, repeated tests against v7.3-rc2 recorded mean throughput increases of 11.06% for stress-ng dnotify and 35.93% for unlink. Tests with orphan_file enabled showed no clear throughput change within the observed boot-to-boot variation. perf c2c shows remote HITM samples on the original shared line, but none on the separate journal line after the change. Local HITM samples and orphan-lock contention remain. Suggested-by: Jan Kara Link: https://lore.kernel.org/all/575wyoks3ldokhrg6v43rxwsegaecod4bgrpbii6jeczy7czbi@a3yq26u52orp/ Signed-off-by: Jonas Zhou --- Changes since v2: - Follow Jan's suggestion to move the orphan tracking fields together below s_journal_triggers, instead of exchanging journal state with the error-reporting and lazy-init fields. - Add an Orphan inode tracking comment. - Rebase and retest against v7.3-rc2. v2: https://lore.kernel.org/all/a33183c1c24ea47a98afdd4756b49365593a2762.1788779199.git.jonaszhou@zhaoxin.com/ v1: https://lore.kernel.org/all/20260903021836.962624-1-jonaszhou-oc@zhaoxin.com/ fs/ext4/ext4.h | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 724a27e8be61..166910914973 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1644,10 +1644,6 @@ struct ext4_sb_info { /* Journaling */ struct journal_s *s_journal; unsigned long s_ext4_flags; /* Ext4 superblock flags */ - struct mutex s_orphan_lock; /* Protects on disk list changes */ - struct list_head s_orphan; /* List of orphaned inodes in on disk - list */ - struct ext4_orphan_info s_orphan_info; unsigned long s_commit_interval; u32 s_max_batch_time; u32 s_min_batch_time; @@ -1786,6 +1782,12 @@ struct ext4_sb_info { /* Journal triggers for checksum computation */ struct ext4_journal_trigger s_journal_triggers[EXT4_JOURNAL_TRIGGER_COUNT]; + /* Orphan inode tracking */ + struct mutex s_orphan_lock; /* Protects on disk list changes */ + struct list_head s_orphan; /* List of orphaned inodes in on disk + list */ + struct ext4_orphan_info s_orphan_info; + /* Ratelimit ext4 messages. */ struct ratelimit_state s_err_ratelimit_state; struct ratelimit_state s_warning_ratelimit_state; base-commit: df2908090cda368b01ff43709f51890076c56157 -- 2.43.0