From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754814AbcEaNMY (ORCPT ); Tue, 31 May 2016 09:12:24 -0400 Received: from mx0b-0016f401.pphosted.com ([67.231.156.173]:7951 "EHLO mx0b-0016f401.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753296AbcEaNLT (ORCPT ); Tue, 31 May 2016 09:11:19 -0400 From: Yehuda Yitschak To: Marcin Wojtas , Robin Murphy CC: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , Lior Amsalem , Thomas Petazzoni , Catalin Marinas , Arnd Bergmann , Grzegorz Jaszczyk , Will Deacon , Nadav Haklai , Tomasz Nowicki , =?utf-8?B?R3JlZ29yeSBDbMOpbWVudA==?= Subject: RE: [BUG] Page allocation failures with newest kernels Thread-Topic: [BUG] Page allocation failures with newest kernels Thread-Index: AQHRuujtIB0RAFh7gkWgmQ3k21VtZ5/SowsAgAADkoCAAF2bYA== Date: Tue, 31 May 2016 13:10:44 +0000 Message-ID: <60e8df74202e40b28a4d53dbc7fd0b22@IL-EXCH02.marvell.com> References: <574D64A0.2070207@arm.com> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.4.102.210] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-05-31_07:,, signatures=0 X-Proofpoint-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=8.0.1-1604210000 definitions=main-1605310151 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id u4VDCVvv003018 Hi Robin During some of the stress tests we also came across a different warning from the arm64 page management code It looks like a race is detected between HW and SW marking a bit in the PTE Not sure it's really related but I thought it might give a clue on the issue http://pastebin.com/ASv19vZP Thanks Yehuda > -----Original Message----- > From: Marcin Wojtas [mailto:mw@semihalf.com] > Sent: Tuesday, May 31, 2016 13:30 > To: Robin Murphy > Cc: linux-mm@kvack.org; linux-kernel@vger.kernel.org; linux-arm- > kernel@lists.infradead.org; Lior Amsalem; Thomas Petazzoni; Yehuda > Yitschak; Catalin Marinas; Arnd Bergmann; Grzegorz Jaszczyk; Will Deacon; > Nadav Haklai; Tomasz Nowicki; Gregory Clément > Subject: Re: [BUG] Page allocation failures with newest kernels > > Hi Robin, > > > > > I remember there were some issues around 4.2 with the revision of the > > arm64 atomic implementations affecting the cmpxchg_double() in SLUB, > > but those should all be fixed (and the symptoms tended to be > considerably more fatal). > > A stronger candidate would be 97303480753e (which landed in 4.4), > > which has various knock-on effects on the layout of SLUB internals - > > does fiddling with L1_CACHE_SHIFT make any difference? > > > > I'll check the commits, thanks. I forgot to add L1_CACHE_SHIFT was my first > suspect - I had spent a long time debugging network controller, which > stopped working because of this change - L1_CACHE_BYTES (and hence > NET_SKB_PAD) not fitting HW constraints. Anyway reverting it didn't help at > all for page alloc issue. > > Best regards, > Marcin