From 26f2fdc47feaf63e3ccfd6139a9a3ecd0b339ab4 Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Fri, 7 Feb 2025 01:20:23 +0900 Subject: [PATCH] btrfs: avoid monopolizing a core when activating a swap file commit 2c8507c63f5498d4ee4af404a8e44ceae4345056 upstream. This commit re-attempts the backport of the change to the linux-5.15.y branch. Commit 214d92f0a465 ("btrfs: avoid monopolizing a core when activating a swap file") on this branch was reverted. During swap activation we iterate over the extents of a file and we can have many thousands of them, so we can end up in a busy loop monopolizing a core. Avoid this by doing a voluntary reschedule after processing each extent. CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Qu Wenruo Signed-off-by: Filipe Manana Signed-off-by: David Sterba Signed-off-by: Koichiro Den Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/inode.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 8f048e517e656..d6e43c94436d4 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -11031,6 +11031,8 @@ static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file, } start += len; + + cond_resched(); } if (bsi.block_len) -- 2.47.3