From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751232AbeFDS4u (ORCPT ); Mon, 4 Jun 2018 14:56:50 -0400 Received: from shelob.surriel.com ([96.67.55.147]:53808 "EHLO shelob.surriel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751182AbeFDS4t (ORCPT ); Mon, 4 Jun 2018 14:56:49 -0400 Message-ID: <1528138607.7898.119.camel@surriel.com> Subject: Re: [PATCH 15/19] sched/numa: Use group_weights to identify if migration degrades locality From: Rik van Riel To: Srikar Dronamraju , Ingo Molnar , Peter Zijlstra Cc: LKML , Mel Gorman , Thomas Gleixner Date: Mon, 04 Jun 2018 14:56:47 -0400 In-Reply-To: <1528106428-19992-16-git-send-email-srikar@linux.vnet.ibm.com> References: <1528106428-19992-1-git-send-email-srikar@linux.vnet.ibm.com> <1528106428-19992-16-git-send-email-srikar@linux.vnet.ibm.com> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-vm/PiTlZVk6smF16HD17" X-Mailer: Evolution 3.26.6 (3.26.6-1.fc27) Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-vm/PiTlZVk6smF16HD17 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, 2018-06-04 at 15:30 +0530, Srikar Dronamraju wrote: >=20 > + dist =3D node_distance(src_nid, dst_nid); > if (numa_group) { > - src_faults =3D group_faults(p, src_nid); > - dst_faults =3D group_faults(p, dst_nid); > + src_weight =3D group_weight(p, src_nid, dist); > + dst_weight =3D group_weight(p, dst_nid, dist); > } else { > - src_faults =3D task_faults(p, src_nid); > - dst_faults =3D task_faults(p, dst_nid); > + src_weight =3D task_weight(p, src_nid, dist); > + dst_weight =3D task_weight(p, dst_nid, dist); > } > =20 > - return dst_faults < src_faults; > + return dst_weight < src_weight; > } While this is better in principle, in practice task/group_weight is a LOT more expensive to calculate than just comparing the faults. This may be too expensive to do in the load balancing code. This patch regressed performance in your synthetic test. How does it do for "real workload" style benchmarks? --=20 All Rights Reversed. --=-vm/PiTlZVk6smF16HD17 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEKR73pCCtJ5Xj3yADznnekoTE3oMFAlsVi28ACgkQznnekoTE 3oPy/gf+MFXl8ZzBs064TLIo9omq8SH8FkR+HfixkP6UIYb7pxwYC3Vdocuq9GYl r3QrqeTBe7K8qdkN7T3rhT5Rgq4GNSG+1nJeHFmPqLGK7RySaHFwESEZmAqjbg0v Gz9DhzSyrIg5LNV4UwynzcpFQ8UGnkt/6nc4tEYm9SQ8c4XNFDU7j74OAhDw0ZHQ 5MwAdXHTWQZbcFmH7UsJN4Y592EAlm1s1TBY54HHwyE38KJZlQVr0saviqGqjsy3 h1CrK/GmhfO6jkX7qd/8qkkayTWcYeMzU6eWMUUM8E272YI56FJ5WmCpXspe5Xw+ E+d83HkNy5UQHEZFskFaXItZXoErOQ== =MKv5 -----END PGP SIGNATURE----- --=-vm/PiTlZVk6smF16HD17--