From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-f197.google.com (mail-qt0-f197.google.com [209.85.216.197]) by kanga.kvack.org (Postfix) with ESMTP id 07E436B03D3 for ; Wed, 5 Apr 2017 18:11:10 -0400 (EDT) Received: by mail-qt0-f197.google.com with SMTP id j30so7046517qta.2 for ; Wed, 05 Apr 2017 15:11:10 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id u127si18925024qkd.249.2017.04.05.15.11.08 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 05 Apr 2017 15:11:08 -0700 (PDT) Message-ID: <1491430264.16856.43.camel@redhat.com> Subject: Re: [PATCH] mm: vmscan: fix IO/refault regression in cache workingset transition From: Rik van Riel Date: Wed, 05 Apr 2017 18:11:04 -0400 In-Reply-To: <20170404220052.27593-1-hannes@cmpxchg.org> References: <20170404220052.27593-1-hannes@cmpxchg.org> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-ZVQRuuSzGMtMeuKPGMPj" Mime-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner , Andrew Morton Cc: Mel Gorman , Michal Hocko , Vladimir Davydov , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com --=-ZVQRuuSzGMtMeuKPGMPj Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2017-04-04 at 18:00 -0400, Johannes Weiner wrote: > + > + /* > + =C2=A0* When refaults are being observed, it means a new > workingset > + =C2=A0* is being established. Disable active list protection to > get > + =C2=A0* rid of the stale workingset quickly. > + =C2=A0*/ This looks a little aggressive. What is this expected to do when you have multiple workloads sharing the same LRU, and one of the workloads is doing refaults, while the other workload is continuing to use the same working set as before? I have been trying to wrap my mind around that for the past day or so, and figure I should just ask the question :) > + if (file && actual_reclaim && lruvec->refaults !=3D refaults) > { > + inactive_ratio =3D 0; > + } else { > + gb =3D (inactive + active) >> (30 - PAGE_SHIFT); > + if (gb) > + inactive_ratio =3D int_sqrt(10 * gb); > + else > + inactive_ratio =3D 1; > + } --=20 All rights reversed --=-ZVQRuuSzGMtMeuKPGMPj Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAABCAAGBQJY5Wt4AAoJEM553pKExN6DwZEH/3vYvvFtryLqCOy63GZcK9lS ytfChfTSDqflsX9lIj06z1LVyQZbeDHO/NcKV8iQa7g2XKYq21piJEm4yfGfR9fT bn0kyKZUhxYB7z8U4qV4mBG5gle2u1O5jxX83c2LGFf4FhueLpJdRZJtXBPb/aBR ojSd+qAF/iVaFrjDlt21eEa0PB5K6QAKHZ2NrA+jGNHeWUVxh1mJUhrIVep+8kfj /4WendQKIZNy5tMzvQWA4mxiV04+gpRMH/4DkKgBzpepCRC3jzKmc8QZi4DYmK1m 3vBJ+Gy3W6M9gKlnFJvFcBlnrynX3ChhKtLpsb1hszKgw43Y/5lHbWCJLB0arfw= =qtdw -----END PGP SIGNATURE----- --=-ZVQRuuSzGMtMeuKPGMPj-- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org