From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751569AbeA2SZ1 (ORCPT ); Mon, 29 Jan 2018 13:25:27 -0500 Received: from mx2.suse.de ([195.135.220.15]:39482 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751249AbeA2SZZ (ORCPT ); Mon, 29 Jan 2018 13:25:25 -0500 Date: Mon, 29 Jan 2018 19:25:21 +0100 From: Michal Hocko To: Florian Westphal Cc: "Kirill A. Shutemov" , Tetsuo Handa , davem@davemloft.net, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org, aarcange@redhat.com, yang.s@alibaba-inc.com, syzkaller-bugs@googlegroups.com, linux-kernel@vger.kernel.org, mingo@kernel.org, linux-mm@kvack.org, rientjes@google.com, akpm@linux-foundation.org, guro@fb.com, kirill.shutemov@linux.intel.com Subject: Re: [netfilter-core] kernel panic: Out of memory and no killable processes... (2) Message-ID: <20180129182521.GI21609@dhcp22.suse.cz> References: <001a1144b0caee2e8c0563d9de0a@google.com> <201801290020.w0T0KK8V015938@www262.sakura.ne.jp> <20180129072357.GD5906@breakpoint.cc> <20180129082649.sysf57wlp7i7ltb2@node.shutemov.name> <20180129165722.GF5906@breakpoint.cc> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180129165722.GF5906@breakpoint.cc> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 29-01-18 17:57:22, Florian Westphal wrote: > Kirill A. Shutemov wrote: > > On Mon, Jan 29, 2018 at 08:23:57AM +0100, Florian Westphal wrote: > > > > vmalloc() once became killable by commit 5d17a73a2ebeb8d1 ("vmalloc: back > > > > off when the current task is killed") but then became unkillable by commit > > > > b8c8a338f75e052d ("Revert "vmalloc: back off when the current task is > > > > killed""). Therefore, we can't handle this problem from MM side. > > > > Please consider adding some limit from networking side. > > > > > > I don't know what "some limit" would be. I would prefer if there was > > > a way to supress OOM Killer in first place so we can just -ENOMEM user. > > > > Just supressing OOM kill is a bad idea. We still leave a way to allocate > > arbitrary large buffer in kernel. > > Isn't that what we do everywhere in network stack? > > I think we should try to allocate whatever amount of memory is needed > for the given xtables ruleset, given that is what admin requested us to do. If this is a root only thing then __GFP_NORETRY sounds like the most straightforward way to go. -- Michal Hocko SUSE Labs