Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755598AbaGNNvj (ORCPT ); Mon, 14 Jul 2014 09:51:39 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:47276 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755272AbaGNNvX (ORCPT ); Mon, 14 Jul 2014 09:51:23 -0400 Date: Mon, 14 Jul 2014 15:51:06 +0200 From: Peter Zijlstra To: Vincent Guittot Cc: Ingo Molnar , linux-kernel , Russell King - ARM Linux , LAK , Preeti U Murthy , Morten Rasmussen , Mike Galbraith , Nicolas Pitre , "linaro-kernel@lists.linaro.org" , Daniel Lezcano , Dietmar Eggemann Subject: Re: [PATCH v3 08/12] sched: move cfs task on a CPU with higher capacity Message-ID: <20140714135106.GZ19379@twins.programming.kicks-ass.net> References: <1404144343-18720-1-git-send-email-vincent.guittot@linaro.org> <1404144343-18720-9-git-send-email-vincent.guittot@linaro.org> <20140710111833.GY3935@laptop> <20140711145138.GC3935@laptop> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="gwj7ZfuSpvxprVSd" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --gwj7ZfuSpvxprVSd Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Jul 11, 2014 at 05:17:44PM +0200, Vincent Guittot wrote: > > In any case, its feels rather arbitrary to me. What about machines where > > there's no cache sharing at all (the traditional SMP systems). This > > thing you're trying to do still seems to make sense there. >=20 > ok, I thought that traditional SMP systems have this flag set at core > level.=20 Yeah, with 1 core, so its effectively disabled. > I mean ARM platforms have the flag for CPUs in the same cluster > (which include current ARM SMP system) and the corei7 of my laptop has > the flag at the cores level. So I can see 'small' parts reducing shared caches in order to improve idle performance. The point being that LLC seems a somewhat arbitrary measure for this. Can we try and see what happens if you remove the limit. Its always best to try the simpler things first and only make it more complex if we have to. --gwj7ZfuSpvxprVSd Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJTw+BKAAoJEHZH4aRLwOS60K8P/RepPIpuAO5/UYo2sz9cAG85 vBXXmfIbf2YhDF7h2UWZ2xpzvN3ql3UfqUbGj6S6I2P2LDST9HcEUXB0/G/VPZQ+ N6IsuK2pMR5ncizZwTB4B412Ch0bYxkYW3AYBOzQdWbtaMtRA2S7BmDWoB1/5M2o edWdFRe3gpU9wAgtAIvDo3lnWF5FRjZmFy9br/NHcUC36KgXyplTX53dueHL047F 2kMf5PCxJ1FkiuqAvPkWE9qcRyO7Gz0c8BstP8/Ytdp2y4iSjgtbieHAsmkfmPn7 Ob3TWLV0af9unx1YTXVnEzhFeJoqsCgoXE2rEqOmQKRRW4O9puo0l6tlB8Nr+/tn OkTjQyxJNSz3Wc61uvb/KFCMpB2km2wkId/G8/6ZCfcjkUzXnI3t5htW5RUCVT7r OWYk4pIjZhrMLhN+MaWXkaeSdWUV4G5YqS4DieRlD/aT0//JCc41Noe7+KuWbBh/ Jir/SO6PVEC9C4/TGMqj3S1JMLMnYvvpNbNTJW+amw8AZ9qpx6uX7mJ/kDblOZFh UOxtnZ3AQh/GhP/Kh+Eoxf0slWOcg38TphD8wh1ADhSTlbdppAa/5FxNa7f0EUKR Oj06VidiOl2Wx6pTVQo7jvqHAckUyb1eoaT4QDnwNq/YG80h0HzSc4je1TktkEG7 kVN3NOc4NDYqnkslyN4q =0/7X -----END PGP SIGNATURE----- --gwj7ZfuSpvxprVSd-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/