From mboxrd@z Thu Jan 1 00:00:00 1970 From: mhocko@kernel.org (Michal Hocko) Date: Wed, 14 Mar 2018 15:54:50 +0100 Subject: [PATCH] Revert "mm/page_alloc: fix memmap_init_zone pageblock alignment" In-Reply-To: References: <20180314134431.13241-1-ard.biesheuvel@linaro.org> <20180314141323.GD23100@dhcp22.suse.cz> Message-ID: <20180314145450.GI23100@dhcp22.suse.cz> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed 14-03-18 14:35:12, Ard Biesheuvel wrote: > On 14 March 2018 at 14:13, Michal Hocko wrote: > > Does http://lkml.kernel.org/r/20180313224240.25295-1-neelx at redhat.com > > fix your issue? From the debugging info you provided it should because > > the patch prevents jumping backwards. > > > > The patch does fix the boot hang. > > But I am concerned that we are papering over a fundamental flaw in > memblock_next_valid_pfn(). It seems that memblock_next_valid_pfn is doing the right thing here. It is the alignment which moves the pfn back AFAICS. I am not really impressed about the original patch either, to be completely honest. It just looks awfully tricky. I still didn't manage to wrap my head around the original issue though so I do not have much better ideas to be honest. -- Michal Hocko SUSE Labs