Re: [PATCH 4.4 24/30] swap: cond_resched in swap_cgroup_prepare()

[Greg Kroah-Hartman]

On Thu, Jun 29, 2017 at 06:23:43PM +0100, Ben Hutchings wrote:
> On Mon, 2017-06-19 at 23:20 +0800, Greg Kroah-Hartman wrote:
> > 4.4-stable review patch.  If anyone has any objections, please let me know.
> > 
> > ------------------
> > 
> > From: Yu Zhao <yuzhao@xxxxxxxxxx>
> > 
> > commit ef70762948dde012146926720b70e79736336764 upstream.
> > 
> > I saw need_resched() warnings when swapping on large swapfile (TBs)
> > because continuously allocating many pages in swap_cgroup_prepare() took
> > too long.
> > 
> > We already cond_resched when freeing page in swap_cgroup_swapoff().  Do
> > the same for the page allocation.
> [...]
> 
> That seems to imply that this should also go into stable branches:
> 
> commit 460bcec84e11c75122ace5976214abbc596eb91b
> Author: David Rientjes <rientjes@xxxxxxxxxx>
> Date:   Fri Apr 7 16:05:00 2017 -0700
> 
>     mm, swap_cgroup: reschedule when neeed in swap_cgroup_swapoff()
>     

Looks like it to me, thanks, now queued up.

greg k-h