From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751530AbeA2SdH (ORCPT ); Mon, 29 Jan 2018 13:33:07 -0500 Received: from a3.inai.de ([88.198.180.161]:52674 "EHLO a3.inai.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751249AbeA2SdF (ORCPT ); Mon, 29 Jan 2018 13:33:05 -0500 Date: Mon, 29 Jan 2018 19:24:01 +0100 (CET) From: Jan Engelhardt 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, mhocko@suse.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) In-Reply-To: <20180129165722.GF5906@breakpoint.cc> Message-ID: References: <001a1144b0caee2e8c0563d9de0a@google.com> <201801290020.w0T0KK8V015938@www262.sakura.ne.jp> <20180129072357.GD5906@breakpoint.cc> <20180129082649.sysf57wlp7i7ltb2@node.shutemov.name> <20180129165722.GF5906@breakpoint.cc> User-Agent: Alpine 2.20 (LSU 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday 2018-01-29 17:57, 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. At the very least, mm could limit that kind of "arbitrary". If the machine has x GB (swap included) and the admin tries to make the kernel allocate space for an x GB ruleset, no way is it going to be satisfiable _even with OOM_. >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.