From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6F64AC433DF for ; Fri, 16 Oct 2020 15:38:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2535220848 for ; Fri, 16 Oct 2020 15:38:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2408563AbgJPPik (ORCPT ); Fri, 16 Oct 2020 11:38:40 -0400 Received: from mx2.suse.de ([195.135.220.15]:34748 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2408427AbgJPPib (ORCPT ); Fri, 16 Oct 2020 11:38:31 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 26A7DADAB; Fri, 16 Oct 2020 15:38:29 +0000 (UTC) To: Mike Rapoport , Muchun Song Cc: Eric Dumazet , Eric Dumazet , Cong Wang , Greg KH , rafael@kernel.org, "Michael S. Tsirkin" , Jason Wang , David Miller , Jakub Kicinski , Alexey Dobriyan , Andrew Morton , Alexey Kuznetsov , Hideaki YOSHIFUJI , Steffen Klassert , Herbert Xu , Shakeel Butt , Will Deacon , Michal Hocko , Roman Gushchin , Neil Brown , Sami Tolvanen , "Kirill A. Shutemov" , Feng Tang , Paolo Abeni , Willem de Bruijn , Randy Dunlap , Florian Westphal , gustavoars@kernel.org, Pablo Neira Ayuso , Dexuan Cui , Jakub Sitnicki , Peter Zijlstra , Christian Brauner , "Eric W. Biederman" , Thomas Gleixner , dave@stgolabs.net, Michel Lespinasse , Jann Horn , chenqiwu@xiaomi.com, christophe.leroy@c-s.fr, Minchan Kim , Martin KaFai Lau , Alexei Starovoitov , Daniel Borkmann , Miaohe Lin , Kees Cook , LKML , virtualization@lists.linux-foundation.org, Linux Kernel Network Developers , linux-fsdevel , linux-mm , Michael Kerrisk References: <20201010103854.66746-1-songmuchun@bytedance.com> <9262ea44-fc3a-0b30-54dd-526e16df85d1@gmail.com> <20201013080906.GD4251@kernel.org> From: Vlastimil Babka Subject: Re: [External] Re: [PATCH] mm: proc: add Sock to /proc/meminfo Message-ID: <8d1558e7-cd09-1f9e-edab-5f22c5bfc342@suse.cz> Date: Fri, 16 Oct 2020 17:38:26 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.3.2 MIME-Version: 1.0 In-Reply-To: <20201013080906.GD4251@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 10/13/20 10:09 AM, Mike Rapoport wrote: >> We are not complaining about TCP using too much memory, but how do >> we know that TCP uses a lot of memory. When I firstly face this problem, >> I do not know who uses the 25GB memory and it is not shown in the /proc/meminfo. >> If we can know the amount memory of the socket buffer via /proc/meminfo, we >> may not need to spend a lot of time troubleshooting this problem. Not everyone >> knows that a lot of memory may be used here. But I believe many people >> should know /proc/meminfo to confirm memory users. > If I undestand correctly, the problem you are trying to solve is to > simplify troubleshooting of memory usage for people who may not be aware > that networking stack can be a large memory consumer. > > For that a paragraph in 'man 5 proc' maybe a good start: Yeah. Another major consumer that I've seen at some point was xfs buffers. And there might be others, and adding everything to /proc/meminfo is not feasible. I have once proposed adding a counter called "Unaccounted:" which would at least tell the user easily if a significant portion is occupied by memory not explained by the other meminfo counters, and look for trends (increase = potential memory leak?). For specific prominent consumers not covered by meminfo but that have some kind of internal counters, we could document where to look, such as /proc/net/sockstat or maybe create some /proc/ or /sys directory with file per consumer so that it's still easy to check, but without the overhead of global counters and bloated /proc/meminfo? > From ddbcf38576d1a2b0e36fe25a27350d566759b664 Mon Sep 17 00:00:00 2001 > From: Mike Rapoport > Date: Tue, 13 Oct 2020 11:07:35 +0300 > Subject: [PATCH] proc.5: meminfo: add not anout network stack memory > consumption > > Signed-off-by: Mike Rapoport > --- > man5/proc.5 | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/man5/proc.5 b/man5/proc.5 > index ed309380b..8414676f1 100644 > --- a/man5/proc.5 > +++ b/man5/proc.5 > @@ -3478,6 +3478,14 @@ Except as noted below, > all of the fields have been present since at least Linux 2.6.0. > Some fields are displayed only if the kernel was configured > with various options; those dependencies are noted in the list. > +.IP > +Note that significant part of memory allocated by the network stack > +is not accounted in the file. > +The memory consumption of the network stack can be queried > +using > +.IR /proc/net/sockstat > +or > +.BR ss (8) > .RS > .TP > .IR MemTotal " %lu" > -- 2.25.4