Re: [PATCH] mm: thp: fix a double unlock bug

From: Mel Gorman
Date: Tue Jun 01 2021 - 06:09:02 EST


On Tue, Jun 01, 2021 at 12:24:09PM +0300, Dan Carpenter wrote:
> We're supposed to be holding the "vmf->ptl" spin_lock when we goto
> out_map. The lock is dropped after if finishes cleaning up.
>
> Fixes: 9aff7b33c74a ("mm: thp: refactor NUMA fault handling")
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

Ouch.

Acked-by: Mel Gorman <mgorman@xxxxxxx>

However, that git commit is not stable. Instead of Fixes: I would
suggest renaming the patch to "mm: thp: refactor NUMA fault handling
-fix" and replacing Fixes with "This patch is a fix to the mmotm patch
mm-thp-refactor-numa-fault-handling.patch". Andrew usually slots that
into the correct place in his quilt series and collapses the fixes before
sending to Linus which works better with bisection.

--
Mel Gorman
SUSE Labs