From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f197.google.com (mail-pf1-f197.google.com [209.85.210.197]) by kanga.kvack.org (Postfix) with ESMTP id 31B158E00A4 for ; Tue, 25 Sep 2018 17:00:09 -0400 (EDT) Received: by mail-pf1-f197.google.com with SMTP id x19-v6so13319756pfh.15 for ; Tue, 25 Sep 2018 14:00:09 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id 37-v6sor438954pgm.152.2018.09.25.14.00.07 for (Google Transport Security); Tue, 25 Sep 2018 14:00:08 -0700 (PDT) Date: Wed, 26 Sep 2018 00:00:02 +0300 From: "Kirill A. Shutemov" Subject: Re: [PATCH] mm: Disable movable allocation for TRANSHUGE pages Message-ID: <20180925210001.j4olzx3fru4jpfys@kshutemo-mobl1> References: <1537860333-28416-1-git-send-email-amhetre@nvidia.com> <20180925115153.z5b5ekijf5jzhzmn@kshutemo-mobl1> <20180925183019.GB22630@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180925183019.GB22630@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Ashish Mhetre , linux-mm@kvack.org, akpm@linux-foundation.org, vdumpa@nvidia.com, Snikam@nvidia.com On Tue, Sep 25, 2018 at 08:30:19PM +0200, Michal Hocko wrote: > On Tue 25-09-18 14:51:53, Kirill A. Shutemov wrote: > > On Tue, Sep 25, 2018 at 12:55:33PM +0530, Ashish Mhetre wrote: > > > TRANSHUGE pages have no migration support. > > > > Transparent pages have migration support since v4.14. > > This is true but not for all architectures AFAICS. In fact git grep > suggests that only x86 supports the migration. So unless I am missing > something the patch has some merit. THP pages are movable from the beginning. Before 4.14, the cost of migration was THP split. From my PoV __GFP_MOVABLE is justified and we should keep it there. -- Kirill A. Shutemov