From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f197.google.com (mail-qk0-f197.google.com [209.85.220.197]) by kanga.kvack.org (Postfix) with ESMTP id 6BCE26B0274 for ; Mon, 30 Jan 2017 11:15:15 -0500 (EST) Received: by mail-qk0-f197.google.com with SMTP id i34so114037930qkh.6 for ; Mon, 30 Jan 2017 08:15:15 -0800 (PST) Received: from www62.your-server.de (www62.your-server.de. [213.133.104.62]) by mx.google.com with ESMTPS id y128si9834778qkc.255.2017.01.30.08.15.14 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 30 Jan 2017 08:15:14 -0800 (PST) Message-ID: <588F668C.6090309@iogearbox.net> Date: Mon, 30 Jan 2017 17:15:08 +0100 From: Daniel Borkmann MIME-Version: 1.0 Subject: Re: [PATCH 0/6 v3] kvmalloc References: <20170126074354.GB8456@dhcp22.suse.cz> <5889C331.7020101@iogearbox.net> <20170126100802.GF6590@dhcp22.suse.cz> <5889DEA3.7040106@iogearbox.net> <20170126115833.GI6590@dhcp22.suse.cz> <5889F52E.7030602@iogearbox.net> <20170126134004.GM6590@dhcp22.suse.cz> <588A5D3C.4060605@iogearbox.net> <20170127100544.GF4143@dhcp22.suse.cz> <588BA9AA.8010805@iogearbox.net> <20170130075626.GC8443@dhcp22.suse.cz> In-Reply-To: <20170130075626.GC8443@dhcp22.suse.cz> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Alexei Starovoitov , Andrew Morton , Vlastimil Babka , Mel Gorman , Johannes Weiner , linux-mm , LKML , "netdev@vger.kernel.org" , marcelo.leitner@gmail.com On 01/30/2017 08:56 AM, Michal Hocko wrote: > On Fri 27-01-17 21:12:26, Daniel Borkmann wrote: >> On 01/27/2017 11:05 AM, Michal Hocko wrote: >>> On Thu 26-01-17 21:34:04, Daniel Borkmann wrote: > [...] >>>> So to answer your second email with the bpf and netfilter hunks, why >>>> not replacing them with kvmalloc() and __GFP_NORETRY flag and add that >>>> big fat FIXME comment above there, saying explicitly that __GFP_NORETRY >>>> is not harmful though has only /partial/ effect right now and that full >>>> support needs to be implemented in future. That would still be better >>>> that not having it, imo, and the FIXME would make expectations clear >>>> to anyone reading that code. >>> >>> Well, we can do that, I just would like to prevent from this (ab)use >>> if there is no _real_ and _sensible_ usecase for it. Having a real bug >> >> Understandable. >> >>> report or a fallback mechanism you are mentioning above would justify >>> the (ab)use IMHO. But that abuse would be documented properly and have a >>> real reason to exist. That sounds like a better approach to me. >>> >>> But if you absolutely _insist_ I can change that. >> >> Yeah, please do (with a big FIXME comment as mentioned), this originally >> came from a real bug report. Anyway, feel free to add my Acked-by then. > > Thanks! I will repost the whole series today. Looks like I got only Cc'ed on the cover letter of your v3 from today (should have been v4 actually?). Anyway, I looked up the last patch on lkml [1] and it seems you forgot the __GFP_NORETRY we talked about? At least that was what was discussed above (insisting on __GFP_NORETRY plus FIXME comment) for providing my Acked-by then. Can you still fix that up in a final respin? Thanks again, Daniel [1] https://lkml.org/lkml/2017/1/30/129 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org