From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oleg Nesterov Subject: Re: [PATCH] mm-move-mremap-from-file_operations-to-vm_operations_struct-fix Date: Mon, 20 Jul 2015 21:24:40 +0200 Message-ID: <20150720192440.GA20573@redhat.com> References: <20150716231405.GA25147@redhat.com> <20150716162444.26425f5e227387f1166a6d16@linux-foundation.org> <20150716235227.GA26551@redhat.com> <20150717140615.GA2779@kvack.org> <20150717223147.GA13259@redhat.com> <20150720173311.GA4379@redhat.com> <20150720175145.GH21558@kvack.org> <20150720183150.GA6868@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20150720183150.GA6868@redhat.com> Sender: linux-kernel-owner@vger.kernel.org To: Benjamin LaHaise Cc: Jeff Moyer , Andrew Morton , Joonsoo Kim , Fengguang Wu , Johannes Weiner , Stephen Rothwell , linux-next@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-next.vger.kernel.org On 07/20, Oleg Nesterov wrote: > > But again, again, please ignore. This all is off-topic and my understanding > is very limited. Yes, yes, but sorry for noise and let me repeat... This memory lives in page-cache/lru, it is visible for shrinker which will unmap these pages for no reason on memory shortage. IOW, aio fools the kernel, this memory looks reclaimable but it is not. And we only do this for migration. Even if this is not a problem, this does not look right. So perhaps at least mapping_set_unevictable() makes sense. But I simply do not know if migration will work with this change. And I should have changes the subject a long ago... So what do you think we should do with the build failure? Oleg.