On Thu, Feb 06, 2025 at 08:41:33PM +0900, Koichiro Den wrote: > On Mon, Dec 30, 2024 at 04:43:39PM GMT, Greg Kroah-Hartman wrote: > > 6.12-stable review patch. If anyone has any objections, please let me know. > > > > ------------------ > > > > From: Filipe Manana <fdmanana@xxxxxxxx> > > > > commit 2c8507c63f5498d4ee4af404a8e44ceae4345056 upstream. > > > > 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@xxxxxxxxxxxxxxx # 5.4+ > > Reviewed-by: Qu Wenruo <wqu@xxxxxxxx> > > Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx> > > Signed-off-by: David Sterba <dsterba@xxxxxxxx> > > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > > --- > > fs/btrfs/inode.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > --- a/fs/btrfs/inode.c > > +++ b/fs/btrfs/inode.c > > @@ -7117,6 +7117,8 @@ noinline int can_nocow_extent(struct ino > > ret = -EAGAIN; > > goto out; > > } > > + > > + cond_resched(); > > } > > > > if (file_extent) > > > > > > Hi, please let me confirm; is this backport really ok? I mean, should the > cond_resched() be added to btrfs_swap_activate() loop? I was able to > reproduce the same situation: > > $ git rev-parse HEAD > 319addc2ad901dac4d6cc931d77ef35073e0942f > $ b4 mbox --single-message c37ea7a8de12e996091ba295b2f201fbe680c96c.1733929328.git.fdmanana@xxxxxxxx > 1 messages in the thread > Saved ./c37ea7a8de12e996091ba295b2f201fbe680c96c.1733929328.git.fdmanana@xxxxxxxxxxxx > $ patch -p1 < ./c37ea7a8de12e996091ba295b2f201fbe680c96c.1733929328.git.fdmanana@xxxxxxxxxxxx > patching file fs/btrfs/inode.c > Hunk #1 succeeded at 7117 with fuzz 1 (offset -2961 lines). > $ git diff > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index 58ffe78132d9..6fe2ac620464 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -7117,6 +7117,8 @@ noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len, > ret = -EAGAIN; > goto out; > } > + > + cond_resched(); > } > > if (file_extent) > > The same goes for all the other stable branches applied. Sorry if I'm > missing something. Hm, looks like patch messed this up :( Can you send a revert for the branches that this was wrong on, and then the correct fix, and I'll be glad to queue them all up. thanks, greg k-h
