From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933394AbcLAMf0 (ORCPT ); Thu, 1 Dec 2016 07:35:26 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:52250 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1758535AbcLAMfX (ORCPT ); Thu, 1 Dec 2016 07:35:23 -0500 Date: Thu, 1 Dec 2016 04:34:09 -0800 From: "Paul E. McKenney" To: Guenter Roeck Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , sparclinux@vger.kernel.org, davem@davemloft.net Subject: Re: next: Commit 'mm: Prevent __alloc_pages_nodemask() RCU CPU stall ...' causing hang on sparc32 qemu Reply-To: paulmck@linux.vnet.ibm.com References: <20161130012817.GH3924@linux.vnet.ibm.com> <20161130070212.GM3924@linux.vnet.ibm.com> <929f6b29-461a-6e94-fcfd-710c3da789e9@roeck-us.net> <20161130120333.GQ3924@linux.vnet.ibm.com> <20161130192159.GB22216@roeck-us.net> <20161130210152.GL3924@linux.vnet.ibm.com> <20161130231846.GB17244@roeck-us.net> <20161201011950.GX3924@linux.vnet.ibm.com> <20161201065657.GA4697@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161201065657.GA4697@roeck-us.net> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16120112-0028-0000-0000-000006298118 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00006173; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000193; SDB=6.00787824; UDB=6.00381134; IPR=6.00565501; BA=6.00004935; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00013502; XFM=3.00000011; UTC=2016-12-01 12:34:10 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16120112-0029-0000-0000-0000314AC4E7 Message-Id: <20161201123409.GA3924@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-12-01_07:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1609300000 definitions=main-1612010220 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 30, 2016 at 10:56:57PM -0800, Guenter Roeck wrote: > Hi Paul, > > On Wed, Nov 30, 2016 at 05:19:50PM -0800, Paul E. McKenney wrote: > [ ... ] > > > > > > > > > > > BUG: sleeping function called from invalid context at mm/page_alloc.c:3775 > [ ... ] > > > > Whew! You had me going for a bit there. ;-) > > Bisect results are here ... the culprit is, again, commit 2d66cccd73 ("mm: > Prevent __alloc_pages_nodemask() RCU CPU stall warnings"), and reverting that > patch fixes the problem. Good that you dropped it already :-). "My work is done." ;-) And apologies for the hassle. I have no idea what I was thinking when I put the cond_resched_rcu_qs() there! Thanx, Paul > Guenter > > --- > # bad: [59ab0083490c8a871b51e893bae5806e55901d7e] Add linux-next specific files for 20161130 > # good: [e5517c2a5a49ed5e99047008629f1cd60246ea0e] Linux 4.9-rc7 > git bisect start 'HEAD' 'v4.9-rc7' > # good: [187f99e5c22bb3fab8b330f3ebbbd235d238f3f8] Merge remote-tracking branch 'crypto/master' > git bisect good 187f99e5c22bb3fab8b330f3ebbbd235d238f3f8 > # good: [36126657c908e822523b8563f9b1512937c0f342] Merge remote-tracking branch 'tip/auto-latest' > git bisect good 36126657c908e822523b8563f9b1512937c0f342 > # good: [2d2139c5c746ec61024fdfa9c36e4e034bb18e59] Merge tag 'iio-for-4.10d' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next > git bisect good 2d2139c5c746ec61024fdfa9c36e4e034bb18e59 > # bad: [926a60551123048c589b45abee2a2ec4c924ab21] Merge remote-tracking branch 'extcon/extcon-next' > git bisect bad 926a60551123048c589b45abee2a2ec4c924ab21 > # bad: [1541655795a90720b8a094c8cc39f582dec17398] Merge remote-tracking branch 'tty/tty-next' > git bisect bad 1541655795a90720b8a094c8cc39f582dec17398 > # bad: [69a6720a1e54519d9bf8563764e9e93bf1bd6a84] Merge remote-tracking branch 'kvm-arm/next' > git bisect bad 69a6720a1e54519d9bf8563764e9e93bf1bd6a84 > # good: [33b8b045b93f9104c61ecad1865af961b3bef03e] Merge remote-tracking branch 'ftrace/for-next' > git bisect good 33b8b045b93f9104c61ecad1865af961b3bef03e > # good: [8370c3d08bd98576d97514eca29970e03767a5d1] kvm: svm: Add kvm_fast_pio_in support > git bisect good 8370c3d08bd98576d97514eca29970e03767a5d1 > # good: [0a895142323de3eebb0b753d3d8c0e768ff179d9] mm: Prevent shrink_node() RCU CPU stall warnings > git bisect good 0a895142323de3eebb0b753d3d8c0e768ff179d9 > # bad: [f8045446ca778333e960dcb9e30a5858ff2b8c20] srcu: Force full grace-period ordering > git bisect bad f8045446ca778333e960dcb9e30a5858ff2b8c20 > # good: [f660d64912ccadadcdce6dfb39eb06924dd93767] doc: Fix RCU requirements typos > git bisect good f660d64912ccadadcdce6dfb39eb06924dd93767 > # good: [d2db185bfee894c573faebed93461e9938bdbb61] rcu: Remove short-term CPU kicking > git bisect good d2db185bfee894c573faebed93461e9938bdbb61 > # bad: [2d66cccd73436ac9985a08e5c2f82e4344f72264] mm: Prevent __alloc_pages_nodemask() RCU CPU stall warnings > git bisect bad 2d66cccd73436ac9985a08e5c2f82e4344f72264 > # good: [34c53f5cd399801b083047cc9cf2ad3ed17c3144] mm: Prevent shrink_node_memcg() RCU CPU stall warnings > git bisect good 34c53f5cd399801b083047cc9cf2ad3ed17c3144 > # first bad commit: [2d66cccd73436ac9985a08e5c2f82e4344f72264] mm: Prevent __alloc_pages_nodemask() RCU CPU stall warnings >