From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933006AbbCRNU1 (ORCPT ); Wed, 18 Mar 2015 09:20:27 -0400 Received: from smtprelay0078.hostedemail.com ([216.40.44.78]:51321 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932899AbbCRNUV (ORCPT ); Wed, 18 Mar 2015 09:20:21 -0400 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Spam-Summary: 50,0,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::::::::::::::::::,RULES_HIT:41:69:355:379:541:599:800:960:967:973:988:989:1260:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1534:1541:1593:1594:1711:1730:1747:1777:1792:2195:2199:2393:2525:2553:2560:2563:2682:2685:2859:2911:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3353:3622:3834:3865:3866:3867:3868:3870:3871:3872:3873:3874:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4250:4425:4560:5007:6261:7514:7576:7875:7901:9025:10004:10400:10848:10967:11026:11232:11658:11914:12043:12517:12519:12740:13069:13141:13230:13311:13357:14096:14097:21080:21088,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0 X-HE-Tag: face43_772f5bfc0b63a X-Filterd-Recvd-Size: 2840 Date: Wed, 18 Mar 2015 09:20:17 -0400 From: Steven Rostedt To: Sebastian Andrzej Siewior Cc: Paul Gortmaker , linux-kernel@vger.kernel.org, linux-rt-users , Thomas Gleixner , Carsten Emde , John Kacur , stable-rt@vger.kernel.org, Nikita Yushchenko , Mike Galbraith Subject: Re: [PATCH RT 26/39] scheduling while atomic in cgroup code Message-ID: <20150318092017.7948f390@gandalf.local.home> In-Reply-To: <5509392E.8000701@linutronix.de> References: <20150312191307.081068717@goodmis.org> <20150312191411.381735145@goodmis.org> <20150317201010.GB26043@windriver.com> <5509392E.8000701@linutronix.de> X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.25; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 18 Mar 2015 09:37:02 +0100 Sebastian Andrzej Siewior wrote: > On 03/17/2015 09:10 PM, Paul Gortmaker wrote: > > [[PATCH RT 26/39] scheduling while atomic in cgroup code] On 12/03/2015 (Thu 15:13) Steven Rostedt wrote: > > > >> 3.14.34-rt32-rc1 stable review patch. > >> If anyone has any objections, please let me know. > >> > >> ------------------ > >> > >> From: Mike Galbraith > >> > >> mm, memcg: make refill_stock() use get_cpu_light() > > > > This looks like only 1/2 of Mike's original patch: > > > > https://lkml.org/lkml/2014/6/21/11 > > > > I suspect that is because 3.18 could only use 1/2 of it, and based on > > the SOB lines, this is backported from 3.18. > > no. I didn't take the upper chunk because get_cpu_var() does only a > preempt_disable() and in that section there is not point of preemption > or a lock in involved. So it is fine the way it is. > The suggest change does a migrate_disable() which is a little more code. > > The lower part (the chunk I applied) invokes drain_stock() and that is > where the sleeping-while-atomic warning came from. > > So is the upper half really required and if so, why? Ug, you are right. I was trying to get this all working that I just applied it based on Paul's suggestion. Looking into it, the part of the patch that was dropped is not needed. /me goes and reverts that change :-( -- Steve > > > The other half applies to 3.14 -- testing in progress; not sure about > > the 3.10-rt and earlier.... > > > > P. > > Sebastian