Re: [v2 PATCH 0/2] mm: mempolicy: fix mbind()'s inconsistent behavior for unmovable pages

From: Yang Shi
Date: Mon Jul 15 2019 - 19:54:22 EST




On 7/15/19 4:51 PM, Yang Shi wrote:


On 7/15/19 3:22 PM, Andrew Morton wrote:
On Sat, 22 Jun 2019 08:20:07 +0800 Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx> wrote:

Changelog
v2: * Fixed the inconsistent behavior by not aborting !vma_migratable()
ÂÂÂÂÂÂ immediately by a separate patch (patch 1/2), and this is also the
ÂÂÂÂÂÂ preparation for patch 2/2. For the details please see the commit
 log. Per Vlastimil.
ÂÂÂÂ * Not abort immediately if unmovable page is met. This should handle
ÂÂÂÂÂÂ non-LRU movable pages and temporary off-LRU pages more friendly.
ÂÂÂÂÂÂ Per Vlastimil and Michal Hocko.

Yang Shi (2):
ÂÂÂÂÂÂ mm: mempolicy: make the behavior consistent when MPOL_MF_MOVE* and MPOL_MF_STRICT were specified
ÂÂÂÂÂÂ mm: mempolicy: handle vma with unmovable pages mapped correctly in mbind

I'm seeing no evidence of review on these two. Could we please take a
look? 2/2 fixes a kernel crash so let's please also think about the
-stable situation.

Thanks for following up this. It seems I have a few patches stalled due to lack of review.

BTW, this would not crash post-4.9 kernel since that BUG_ON had been removed. But, that behavior is definitely problematic as the commit log elaborated.


I have a note here that Vlastimil had an issue with [1/2] but I seem to
hae misplaced that email :(

Vlastimil suggested something for v1, then I think his concern and suggestion have been solved in this version. But, the review was stalled.