From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751457AbaETAAe (ORCPT ); Mon, 19 May 2014 20:00:34 -0400 Received: from casper.infradead.org ([85.118.1.10]:59291 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750758AbaETAAd (ORCPT ); Mon, 19 May 2014 20:00:33 -0400 Date: Tue, 20 May 2014 02:00:26 +0200 From: Peter Zijlstra To: Kirill Tkhai Cc: Juri Lelli , "linux-kernel@vger.kernel.org" , "mingo@redhat.com" , "stable@vger.kernel.org" Subject: Re: [PATCH] sched/dl: Fix race between dl_task_timer() and sched_setaffinity() Message-ID: <20140520000026.GD11096@twins.programming.kicks-ass.net> References: <20140516213003.10384.7946.stgit@localhost> <20140519151233.5043b749361e1b384f1e5562@gmail.com> <783871400527879@web2j.yandex.ru> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="IJmQ7d57n2fskpx3" Content-Disposition: inline In-Reply-To: <783871400527879@web2j.yandex.ru> 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 --IJmQ7d57n2fskpx3 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, May 19, 2014 at 11:31:19PM +0400, Kirill Tkhai wrote: > @@ -513,9 +513,17 @@ static enum hrtimer_restart dl_task_timer(struct hrt= imer *timer) > struct sched_dl_entity, > dl_timer); > struct task_struct *p =3D dl_task_of(dl_se); > - struct rq *rq =3D task_rq(p); > + struct rq *rq; > +again: > + rq =3D task_rq(p); > raw_spin_lock(&rq->lock); > =20 > + if (unlikely(rq !=3D task_rq(p))) { > + /* Task was moved, retrying. */ > + raw_spin_unlock(&rq->lock); > + goto again; > + } > + That thing is called: rq =3D __task_rq_lock(p); --IJmQ7d57n2fskpx3 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJTepsVAAoJEHZH4aRLwOS6Nw8QAI/+wt1Vo66IoVvLg4BXkkdp /qZO5ZcAopKW0AFFXj2l4kTB2zrz+s/bK+2g6Sn9RVvf5YfzbRY9uVwTGh48es4b qTNBTZ07Mww/HategKt+mJctiIsvB3zcwu8cP5GGfgwo4wXKJk3jner61wjsz1NT wZ/SRqn0uWN/Jy0lhBztdkRW/F9f1kOG5K/KDa5+WYTLUoX9y43crS/OBBweM2MT WgJFnFm45dfgq5VBsm3/KuOdSIXyHIZmhvDy7AE3yGItLhu1qKLTjjbIo15ERqQv H0ySmWMfgmygpLSSJ/fjmMPSXpeQKZcPu7We/mCJjuuodTVlga0wb6mLgy4r1lmP LnU9bbULjtQsF20mMI2P8nD1AfsAAs2Be9KaEPEkqOLt/Jm6gWnq8hllJVVmV0Oq NQxQyXkRAc6qMbBkNepKMEni9JEA6Tum0LJwXuFK6eKl+F7LAy2YaMIFgodbFrbi vXKOAXrumfUC/OlqBnfa8ytQfDEOf3rh713J1Tontfq0faUGvy9pBJqzW1lQI5x4 iY9vLhqwaqLsEUnz3tev7dJJil9vYN83eIYAKsl8rIvdPYfeP6wX4mN+IIdE5Oi6 cuuX8SWI+oBuZzuPrIIOtsXql6zl8fFWWsojQbXFmIElgUMxUphbcjGPlvv/aiFI xM4dnrxd5i8ZF30jB8h+ =UgSc -----END PGP SIGNATURE----- --IJmQ7d57n2fskpx3--