From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 75E01C35641 for ; Fri, 21 Feb 2020 22:35:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 52FFC206EF for ; Fri, 21 Feb 2020 22:35:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728792AbgBUWfW (ORCPT ); Fri, 21 Feb 2020 17:35:22 -0500 Received: from shelob.surriel.com ([96.67.55.147]:46516 "EHLO shelob.surriel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726731AbgBUWfW (ORCPT ); Fri, 21 Feb 2020 17:35:22 -0500 Received: from imladris.surriel.com ([96.67.55.152]) by shelob.surriel.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.92.3) (envelope-from ) id 1j5GtD-0003s1-6Q; Fri, 21 Feb 2020 17:35:19 -0500 Message-ID: <67d927c6161b15664b4a912ad34fc3a147109760.camel@surriel.com> Subject: Re: [PATCH 2/2] mm,thp,compaction,cma: allow THP migration for CMA allocations From: Rik van Riel To: Zi Yan Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, akpm@linux-foundation.org, linux-mm@kvack.org, mhocko@kernel.org, vbabka@suse.cz, mgorman@techsingularity.net, rientjes@google.com, aarcange@redhat.com Date: Fri, 21 Feb 2020 17:35:15 -0500 In-Reply-To: References: <3289dc5e6c4c3174999598d8293adf8ed3e93b57.1582321645.git.riel@surriel.com> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-N3fCwb3Sg4Ms25pOkexS" User-Agent: Evolution 3.34.3 (3.34.3-1.fc31) MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-N3fCwb3Sg4Ms25pOkexS Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, 2020-02-21 at 17:31 -0500, Zi Yan wrote: > On 21 Feb 2020, at 16:53, Rik van Riel wrote: >=20 > > +++ b/mm/compaction.c > > @@ -894,12 +894,12 @@ isolate_migratepages_block(struct > > compact_control *cc, unsigned long low_pfn, > >=20 > > /* > > * Regardless of being on LRU, compound pages such as > > THP and > > - * hugetlbfs are not to be compacted. We can > > potentially save > > - * a lot of iterations if we skip them at once. The > > check is > > - * racy, but we can consider only valid values and the > > only > > - * danger is skipping too much. > > + * hugetlbfs are not to be compacted most of the time. > > We can > > + * potentially save a lot of iterations if we skip them > > at > > + * once. The check is racy, but we can consider only > > valid > > + * values and the only danger is skipping too much. > > */ >=20 > Maybe add =E2=80=9Cwe do want to move them when allocating contiguous mem= ory > using CMA=E2=80=9D to help > people understand the context of using cc->alloc_contig? I can certainly do that. I'll wait for feedback from other people to see if more changes are wanted, and plan to post v2 by Tuesday or so :) --=20 All Rights Reversed. --=-N3fCwb3Sg4Ms25pOkexS Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEKR73pCCtJ5Xj3yADznnekoTE3oMFAl5QWyMACgkQznnekoTE 3oNG4Qf+NIlz59enImNBYGxlLc+a6Zw6OUfHlPKtL3xXWApRER8KxyzqehnAaDHD 2SyRCoaOObt30qL9telaoqfinbnZP57ud4cpuUrhZ6R/EPYvhWmPzOCuy/ON8n1q J3+SPHSHIdpO0yLqECbkjh8yqqcgeH4MRzvAkUlJ5sl7zLzMUcXLM4lAMRIPP3bE t3GEAVk32mZlYWVowBgYbqTXOPdvha/nJpqpQVOHqLXKDxho/GgXmBzBxqk/JTPd HOHmd9VCOgdmMiylg+s+WVaEP4iGJkE+QrtywHtKVwvYCyOdcTp5d6vAK0Dv85a3 2CU5VojKKKWQL74efpSrnIrmMdGGqQ== =/pq0 -----END PGP SIGNATURE----- --=-N3fCwb3Sg4Ms25pOkexS--