From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lb0-f198.google.com (mail-lb0-f198.google.com [209.85.217.198]) by kanga.kvack.org (Postfix) with ESMTP id 357E06B007E for ; Thu, 2 Jun 2016 09:52:30 -0400 (EDT) Received: by mail-lb0-f198.google.com with SMTP id ne4so24516096lbc.1 for ; Thu, 02 Jun 2016 06:52:30 -0700 (PDT) Received: from outbound-smtp11.blacknight.com (outbound-smtp11.blacknight.com. [46.22.139.16]) by mx.google.com with ESMTPS id a195si1531891wma.36.2016.06.02.06.52.28 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 02 Jun 2016 06:52:28 -0700 (PDT) Received: from mail.blacknight.com (pemlinmail01.blacknight.ie [81.17.254.10]) by outbound-smtp11.blacknight.com (Postfix) with ESMTPS id 3864D1C148B for ; Thu, 2 Jun 2016 14:52:28 +0100 (IST) Date: Thu, 2 Jun 2016 14:52:26 +0100 From: Mel Gorman Subject: Re: [BUG] Page allocation failures with newest kernels Message-ID: <20160602135226.GX2527@techsingularity.net> References: <574D64A0.2070207@arm.com> <60e8df74202e40b28a4d53dbc7fd0b22@IL-EXCH02.marvell.com> <20160531131520.GI24936@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Marcin Wojtas Cc: Will Deacon , Yehuda Yitschak , Robin Murphy , "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 , Nadav Haklai , Tomasz Nowicki , Gregory =?iso-8859-15?Q?Cl=E9ment?= On Thu, Jun 02, 2016 at 07:48:38AM +0200, Marcin Wojtas wrote: > Hi Will, > > I think I found a right trace. Following one-liner fixes the issue > beginning from v4.2-rc1 up to v4.4 included: > > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -294,7 +294,7 @@ static inline bool > early_page_uninitialised(unsigned long pfn) > > static inline bool early_page_nid_uninitialised(unsigned long pfn, int nid) > { > - return false; > + return true; > } > How does that make a difference in v4.4 since commit 974a786e63c96a2401a78ddba926f34c128474f1 removed the only early_page_nid_uninitialised() ? It further doesn't make sense if deferred memory initialisation is not enabled as the pages will always be initialised. > From what I understood, now order-0 allocation keep no reserve at all. Watermarks should still be preserved. zone_watermark_ok is still there. What might change is the size of reserves for high-order atomic allocations only. Fragmentation shouldn't be a factor. I'm missing some major part of the picture. -- Mel Gorman SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org