Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753240AbbFHS7Q (ORCPT ); Mon, 8 Jun 2015 14:59:16 -0400 Received: from mail-yk0-f174.google.com ([209.85.160.174]:35870 "EHLO mail-yk0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752601AbbFHS7D (ORCPT ); Mon, 8 Jun 2015 14:59:03 -0400 Message-ID: <5575E5E6.20908@gmail.com> Date: Mon, 08 Jun 2015 14:58:46 -0400 From: Austin S Hemmelgarn User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: David Rientjes CC: Michal Hocko , Andrew Morton , linux-mm@kvack.org, LKML Subject: Re: [PATCH] oom: split out forced OOM killer References: <1433235187-32673-1-git-send-email-mhocko@suse.cz> <557187F9.8020301@gmail.com> In-Reply-To: x-hashcash: 1:21:150608:rientjes@google.com::350ead482b805d3f5c6c3167d88d4ce1:abe3f8e632bd434d x-hashcash: 1:21:150608:mhocko@suse.cz::3a82acaa6625f83b37bb2f69fe66df08:b1d7e63eef284a72 x-hashcash: 1:21:150608:akpm@linux-foundation.org::8c44fbb3008eacfd613b213f555255e7:1c5c25722455220a x-hashcash: 1:21:150608:linux-mm@kvack.org::40909f4af5cba48080f4257c89521b75:1c0164124d6ae332 x-hashcash: 1:21:150608:linux-kernel@vger.kernel.org::d7baea5672ed9d461cfdf9e65a6c8705:4f3e4ca2be727d76 x-stampprotocols: hashcash:1:17;mbound:0:10:3000:5000 Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha1; boundary="------------ms080701090806070800040104" X-Antivirus: avast! (VPS 150608-0, 2015-06-08), Outbound message X-Antivirus-Status: Clean Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6174 Lines: 109 This is a cryptographically signed message in MIME format. --------------ms080701090806070800040104 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: quoted-printable On 2015-06-08 13:59, David Rientjes wrote: > On Fri, 5 Jun 2015, Austin S Hemmelgarn wrote: > >>> I'm not sure what the benefit of this is, and it's adding more code. >>> Having multiple pathways and requirements, such as constrained_alloc(= ), to >>> oom kill a process isn't any clearer, in my opinion. It also isn't >>> intended to be optimized since the oom killer called from the page >>> allocator and from sysrq aren't fastpaths. To me, this seems like on= ly a >>> source code level change and doesn't make anything more clear but rat= her >>> adds more code and obfuscates the entry path. >> >> At the very least, it does make the semantics of sysrq-f much nicer fo= r admins >> (especially the bit where it ignores the panic_on_oom setting, if the = admin >> wants the system to panic, he'll use sysrq-c). There have been times = I've had >> to hit sysrq-f multiple times to get to actually kill anything, and th= is looks >> to me like it would eliminate that rather annoying issue as well. >> > > Are you saying there's a functional change with this patch/ > I believe so (haven't actually read the patch itself, just the=20 changelog), although it is only a change for certain configurations to a = very specific and (I hope infrequently) used piece of functionality.=20 Like I said above, if I wanted to crash my system, I'd be using sysrq-c; = and if I'm using sysrq-f, I want _some_ task to die _now_. --------------ms080701090806070800040104 Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIIGuDCC BrQwggScoAMCAQICAxBuVTANBgkqhkiG9w0BAQ0FADB5MRAwDgYDVQQKEwdSb290IENBMR4w 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