From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752523Ab1ITWUn (ORCPT ); Tue, 20 Sep 2011 18:20:43 -0400 Received: from lennier.cc.vt.edu ([198.82.162.213]:34142 "EHLO lennier.cc.vt.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752317Ab1ITWUm (ORCPT ); Tue, 20 Sep 2011 18:20:42 -0400 X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.3-dev To: Christoph Lameter Cc: Steven Rostedt , linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton , Thomas Gleixner , Peter Zijlstra , Christoph Lameter Subject: Re: [RFC][PATCH 2/5] mm: Switch mod_state() to __this_cpu_read() In-Reply-To: Your message of "Tue, 20 Sep 2011 10:54:10 CDT." From: Valdis.Kletnieks@vt.edu References: <20110919212040.745370781@goodmis.org> <20110919212640.688732950@goodmis.org> <1316476089.29966.9.camel@gandalf.stny.rr.com> <1316531769.29966.61.camel@gandalf.stny.rr.com> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1316557142_2679P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Tue, 20 Sep 2011 18:19:02 -0400 Message-ID: <25631.1316557142@turing-police.cc.vt.edu> X-Mirapoint-Received-SPF: 198.82.161.152 auth3.smtp.vt.edu Valdis.Kletnieks@vt.edu 2 pass X-Junkmail-Status: score=10/50, host=vivi.cc.vt.edu X-Junkmail-Signature-Raw: score=unknown, refid=str=0001.0A02020B.4E791168.00C1,ss=1,fgs=0, ip=0.0.0.0, so=2010-07-22 22:03:31, dmn=2009-09-10 00:05:08, mode=single engine X-Junkmail-IWF: false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --==_Exmh_1316557142_2679P Content-Type: text/plain; charset=us-ascii On Tue, 20 Sep 2011 10:54:10 CDT, Christoph Lameter said: > IT DOES!!!! The memcg bug is caused by someone using this_cpu_read and > expecting the cpu not to change. this_cpu_xx ops stand on their own and do > not guarantee access to the same per cpu area. As most 6 year olds will tell you, "Well, DUH!". Maybe if you had called it "this_cpu_or_maybe_that_one_over_there_read()", people wouldn't use it wrong. "If people place a nice chocky in their mouth, they don't want their cheeks pierced. In any case this is an inadequate description of the sweetmeat. I shall have to ask you to accompany me to the station." -- Monty Python. "inadequate description" hardly begins to cover the design of this API, which definitely needs to be taken to the station. --==_Exmh_1316557142_2679P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Exmh version 2.5 07/13/2001 iD8DBQFOeRFWcC3lWbTT17ARAmB6AJ9AmXFl+zQUScH2FgyoY3gQcAqp0wCcD13c xHluKi7tYJbPbcxhaixSYTI= =I0Qc -----END PGP SIGNATURE----- --==_Exmh_1316557142_2679P--