From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f70.google.com (mail-ed1-f70.google.com [209.85.208.70]) by kanga.kvack.org (Postfix) with ESMTP id 076668E0001 for ; Wed, 12 Sep 2018 03:50:59 -0400 (EDT) Received: by mail-ed1-f70.google.com with SMTP id d47-v6so519434edb.3 for ; Wed, 12 Sep 2018 00:50:58 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id k15-v6si600302edb.253.2018.09.12.00.50.57 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 12 Sep 2018 00:50:57 -0700 (PDT) Date: Wed, 12 Sep 2018 09:50:54 +0200 From: Michal Hocko Subject: Re: [RFC PATCH 0/3] rework mmap-exit vs. oom_reaper handover Message-ID: <20180912075054.GZ10951@dhcp22.suse.cz> References: <1536382452-3443-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> <20180910125513.311-1-mhocko@kernel.org> <70a92ca8-ca3e-2586-d52a-36c5ef6f7e43@i-love.sakura.ne.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <70a92ca8-ca3e-2586-d52a-36c5ef6f7e43@i-love.sakura.ne.jp> Sender: owner-linux-mm@kvack.org List-ID: To: Tetsuo Handa Cc: linux-mm@kvack.org, Roman Gushchin , Andrew Morton On Tue 11-09-18 23:01:57, Tetsuo Handa wrote: > On 2018/09/10 21:55, Michal Hocko wrote: > > This is a very coarse implementation of the idea I've had before. > > Please note that I haven't tested it yet. It is mostly to show the > > direction I would wish to go for. > > Hmm, this patchset does not allow me to boot. ;-) > > free_pgd_range(&tlb, vma->vm_start, vma->vm_prev->vm_end, > FIRST_USER_ADDRESS, USER_PGTABLES_CEILING); > > [ 1.875675] sched_clock: Marking stable (1810466565, 65169393)->(1977240380, -101604422) > [ 1.877833] registered taskstats version 1 > [ 1.877853] Loading compiled-in X.509 certificates > [ 1.878835] zswap: loaded using pool lzo/zbud > [ 1.880835] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 This is vm_prev == NULL. I thought we always have vm_prev as long as this is not a single VMA in the address space. I will double check this. -- Michal Hocko SUSE Labs