Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754536AbYLHRIS (ORCPT ); Mon, 8 Dec 2008 12:08:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754205AbYLHRH7 (ORCPT ); Mon, 8 Dec 2008 12:07:59 -0500 Received: from mail.klingt.org ([86.59.21.178]:48320 "EHLO klingt.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753446AbYLHRH6 (ORCPT ); Mon, 8 Dec 2008 12:07:58 -0500 Subject: Re: [PATCH] [RT] avoid preemption in memory controller code From: Tim Blechmann To: Steven Rostedt Cc: linux-rt-users , LKML , Peter Zijlstra , Thomas Gleixner , Ingo Molnar In-Reply-To: References: <1228746854-23875-1-git-send-email-tim@klingt.org> Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-MUR0zWqfO8LZinAN8o6L" Date: Mon, 08 Dec 2008 18:07:36 +0100 Message-Id: <1228756056.7862.8.camel@thinkpad> Mime-Version: 1.0 X-Mailer: Evolution 2.24.2 X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-3.0 (klingt.org [127.0.0.1]); Mon, 08 Dec 2008 18:07:37 +0100 (CET) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1378 Lines: 48 --=-MUR0zWqfO8LZinAN8o6L Content-Type: text/plain Content-Transfer-Encoding: quoted-printable > > the lru_lock of struct mem_group_per_zone is used to avoid preemption > > during the __mem_cgroup_stat_add_safe function. > > therefore, a raw_spinlock_t should be used. >=20 > What is the reason that this must avoid preemption?=20 it guards a call to smp_processor_id() in __mem_cgroup_stat_add_safe(). see http://article.gmane.org/gmane.linux.rt.user/3690 > Is there another > way to solve this? I rather not just add a raw spinlock if we can > help it. not sure, maybe one can disable preemption for that specific function? tim -- tim@klingt.org http://tim.klingt.org Art is either a complaint or do something else John Cage quoting Jasper Johns --=-MUR0zWqfO8LZinAN8o6L Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEABECAAYFAkk9VFMACgkQFz+XezW6HD4eqQCgxBvOMt6an7l+8z5D9oBB8jta F/0Anj3ab0Y4xJzIbR/GwbYPgczkty9T =6g9o -----END PGP SIGNATURE----- --=-MUR0zWqfO8LZinAN8o6L-- -- 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/