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In-Reply-To: <alpine.DEB.2.21.1812071421030.148470@chino.kir.corp.google.com>
From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Fri, 7 Dec 2018 14:33:40 -0800
Message-ID: <CAHk-=wiGjzXQSPhq-TNkwUAqZKNobOgyJJKMXFooaOMyDDG38g@mail.gmail.com>
Subject: Re: [patch for-4.20] Revert "mm, thp: consolidate THP gfp handling
 into alloc_hugepage_direct_gfpmask"
To:     David Rientjes <rientjes@google.com>
Cc:     Vlastimil Babka <vbabka@suse.cz>,
        Andrea Arcangeli <aarcange@redhat.com>,
        mgorman@techsingularity.net, Michal Hocko <mhocko@kernel.org>,
        ying.huang@intel.com, s.priebe@profihost.ag,
        Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
        alex.williamson@redhat.com, lkp@01.org, kirill@shutemov.name,
        Andrew Morton <akpm@linux-foundation.org>,
        zi.yan@cs.rutgers.edu
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On Fri, Dec 7, 2018 at 2:27 PM David Rientjes <rientjes@google.com> wrote:
>
> I noticed the race in 89c83fb539f9 ("mm, thp: consolidate THP gfp handling
> into alloc_hugepage_direct_gfpmask") that is fixed by the revert, but as
> you noted it didn't cleanup the second part which is the balancing act for
> gfp flags between alloc_hugepage_direct_gfpmask() and alloc_pages_vma().
> Syzbot found this to trigger the WARN_ON_ONCE() you mention.

Can you rewrite the commit message to explain this better rather than
the misleading "race" description?

                 Linus

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