Re: [PATCH stable-only] mm: fix classzone_idx underflow in shrink_zones()

From: Greg KH
Date: Tue Jul 04 2017 - 04:55:44 EST


On Tue, Jul 04, 2017 at 10:45:43AM +0200, Vlastimil Babka wrote:
> Hi,
>
> I realize this is against the standard stable policy, but I see no other
> way, because the mainline accidental fix is part of 34+ patch reclaim
> rework, that would be absurd to try to backport into stable. The fix is
> a one-liner though.
>
> The bug affects at least 4.4.y, and likely also older stable trees that
> backported commit 7bf52fb891b6, which itself was a fix for 3.19 commit
> 6b4f7799c6a5. You could revert the 7bf52fb891b6 backport, but then 32bit
> with highmem might suffer from OOM or thrashing.

I need a bunch of acks from developers in this area before I can take
this patch :)

thanks,

greg k-h