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Date: Tue, 13 May 2014 22:19:57 -0700 (PDT)
From: Hugh Dickins <hughd@google.com>
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To: Sasha Levin <sasha.levin@oracle.com>
cc: Vlastimil Babka <vbabka@suse.cz>,
        Andrew Morton <akpm@linux-foundation.org>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Mel Gorman <mgorman@suse.de>, Yong-Taek Lee <ytk.lee@samsung.com>,
        Minchan Kim <minchan@kernel.org>,
        KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Hugh Dickins <hughd@google.com>, Rik van Riel <riel@redhat.com>,
        Michal Nazarewicz <mina86@mina86.com>, Dave Jones <davej@redhat.com>
Subject: Re: [PATCH 2/2] mm/page_alloc: DEBUG_VM checks for free_list placement
 of CMA and RESERVE pages
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On Tue, 13 May 2014, Sasha Levin wrote:
> On 05/05/2014 11:50 AM, Vlastimil Babka wrote:
> > So in the end this VM_DEBUG check probably cannot work anymore for MIGRATE_RESERVE, only for CMA. I'm not sure if it's worth keeping it only for CMA, what are the CMA guys' opinions on that?
> 
> The way I understood it is that this patch is wrong, but it's still
> alive in -mm. Should it still be there?

I agree that it should be dropped.  I did not follow the discussion,
but mmotm soon gives me BUG at mm/page_alloc.c:1242 under swapping load.

Hugh