From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752046AbaEVPfL (ORCPT ); Thu, 22 May 2014 11:35:11 -0400 Received: from casper.infradead.org ([85.118.1.10]:46034 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750741AbaEVPfK (ORCPT ); Thu, 22 May 2014 11:35:10 -0400 Date: Thu, 22 May 2014 17:35:04 +0200 From: Peter Zijlstra To: Ben Segall Cc: Ingo Molnar , Roman Gushchin , pjt@google.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] sched: fix unlocked reads of some cfs_b->quota/period Message-ID: <20140522153504.GY30445@twins.programming.kicks-ass.net> References: <20140519224945.20303.93530.stgit@sword-of-the-dawn.mtv.corp.google.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="+aOZGdcGYL8FotQd" Content-Disposition: inline In-Reply-To: <20140519224945.20303.93530.stgit@sword-of-the-dawn.mtv.corp.google.com> 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 --+aOZGdcGYL8FotQd Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, May 19, 2014 at 03:49:45PM -0700, Ben Segall wrote: > @@ -3783,7 +3787,7 @@ static void __maybe_unused unthrottle_offline_cfs_r= qs(struct rq *rq) > * clock_task is not advancing so we just need to make sure > * there's some valid quota amount > */ > - cfs_rq->runtime_remaining =3D cfs_b->quota; > + cfs_rq->runtime_remaining =3D 1; > if (cfs_rq_throttled(cfs_rq)) > unthrottle_cfs_rq(cfs_rq); > } >=20 That ^, causes: kernel/sched/fair.c: In function =E2=80=98unthrottle_offline_cfs_rqs=E2=80= =99: kernel/sched/fair.c:3782:25: warning: unused variable =E2=80=98cfs_b=E2=80= =99 [-Wunused-variable] Stuck this on: --- --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3779,8 +3779,6 @@ static void __maybe_unused unthrottle_of struct cfs_rq *cfs_rq; =20 for_each_leaf_cfs_rq(rq, cfs_rq) { - struct cfs_bandwidth *cfs_b =3D tg_cfs_bandwidth(cfs_rq->tg); - if (!cfs_rq->runtime_enabled) continue; =20 --+aOZGdcGYL8FotQd Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJTfhkoAAoJEHZH4aRLwOS6ZaAP/AmeXKLl41uwgnmNO0J1E9QU cMFddjEfYw+4tanJ/IyU0oO+wKtbP3cFRgXZ3sfgqwSWbpRGKiXJIwp/2nu9bVsY HUrCIT7bgmfNo20nwfYUoKC4dtoSzBgyyc/Nm/oHQzSwOXiKkC31F0+H4+i15lXw RIuvdE/rNTBYl2O1HXwNpKbF0WYsB9sKFwId8brTLV+1A9OJMDSDkHBxZzNQ170W 8nQaDVmzwj1GhZP9xfR/F2WlBk6AS0oEAitXa4bCN777M9eKptKm5pPQvg8KSs4V zvkERxpCjkh4/fDhfpy1styY1HS+kp58Hn8jEUkAV9EUn2H+6tu0Ki3Lr8hRLs3S fNMP0Wvrw+zwPmy32Bg8vHC1VdFFGV2z340+ivm+cnD/qR59Ehib9t/PqAobQ6dE OYwoXZ2yJAR4zxnPbuhbJytF2aaYLHtvJhWD+gBBPFI5BCYnaO9uwMLMZmkJSIQC oJLG6PCN1YLjVwzXUxuQKxGs/cuXmXy/6S6k6QNsHNpPwOEfsNFj7ZeXuMBVZ7LY cdpsEo3I/wGf4x6WN71gLXqHffJ8g4XrCmIJ6KhsCvwWd3OdBuZUv2CRlDUCGF0V ksa06vmVpklHBrYcUCZkoTuQD8nLoHByIFWP1bQVmzSX7cp1ESMmN6xzZ+1+CtH7 J1/g18ukxmSGaZU3i1b4 =jOy7 -----END PGP SIGNATURE----- --+aOZGdcGYL8FotQd--