btrfs: avoid monopolizing a core when activating a swap file

commit 2c8507c63f upstream.

This commit re-attempts the backport of the change to the linux-6.6.y
branch. Commit 6e1a822593 ("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 <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This commit is contained in:

Filipe Manana

2025-02-07 01:21:31 +09:00

committed by

Greg Kroah-Hartman

parent b4e355e70e

commit 893b28374a

1 changed files with 2 additions and 0 deletions

									
										fs/btrfs/inode.c
									
		+2
		
												View File
												
				@@ -10833,6 +10833,8 @@ static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file,

						}

						start += len;

						cond_resched();

					}

					if (bsi.block_len)