From abaf4783822851678632e5cea98aa5aead99852f Mon Sep 17 00:00:00 2001 From: Abd-Alrhman Masalkhi Date: Tue, 28 Apr 2026 15:05:24 +0200 Subject: [PATCH] md: skip redundant raid_disks update when value is unchanged Calling update_raid_disks() with the same value as the current one can trigger unnecessary work. For example, RAID1 will reallocate resources such as the mempool for r1bio. Signed-off-by: Abd-Alrhman Masalkhi Link: https://patch.msgid.link/20260428130524.448063-1-abd.masalkhi@gmail.com Signed-off-by: Yu Kuai --- drivers/md/md.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 8b568eee8743..6cb2c452f963 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -4414,9 +4414,10 @@ raid_disks_store(struct mddev *mddev, const char *buf, size_t len) err = mddev_suspend_and_lock(mddev); if (err) return err; - if (mddev->pers) - err = update_raid_disks(mddev, n); - else if (mddev->reshape_position != MaxSector) { + if (mddev->pers) { + if (n != mddev->raid_disks) + err = update_raid_disks(mddev, n); + } else if (mddev->reshape_position != MaxSector) { struct md_rdev *rdev; int olddisks = mddev->raid_disks - mddev->delta_disks;