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=-6.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 79888C433E0 for ; Mon, 15 Mar 2021 17:58:50 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0490F64F17 for ; Mon, 15 Mar 2021 17:58:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0490F64F17 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 841A86B0036; Mon, 15 Mar 2021 13:58:49 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7F1E86B006C; Mon, 15 Mar 2021 13:58:49 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6927C6B0070; Mon, 15 Mar 2021 13:58:49 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0127.hostedemail.com [216.40.44.127]) by kanga.kvack.org (Postfix) with ESMTP id 4A74F6B0036 for ; Mon, 15 Mar 2021 13:58:49 -0400 (EDT) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id E90876C06 for ; Mon, 15 Mar 2021 17:58:48 +0000 (UTC) X-FDA: 77922869136.16.C145152 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf09.hostedemail.com (Postfix) with ESMTP id 46F6C601EB4F for ; Mon, 15 Mar 2021 17:09:49 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 8C141600CD; Mon, 15 Mar 2021 17:09:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1615828184; bh=zcAvAGDwBXL4yn9+QAipdGh2ahuWzmm+14R4I24+RkE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=g6Iu0CEZAFaH5Jg9ZoCgtWqgWKonb1NUFHkQBS+M3GiQKDr1/V6urCCfAQusUacWg 9IEoYmTBriW3L1iLGoMQh2ng98CeiB7GT/qpZofsexz8wcH6gvisOU2jD2eAplAtwL tvvDVOYwUEK+SvCMDpY+hA+Yi6q4KV4Mapbp6Ucwe2s8nzGdNn/GKT6uq0EXtFKNzo +ejhdyR3aultI9g8H7wVlV7YZMKr5CLOEXJKDHKrK5Ag/yYSyY5suey7dsE0njPUx7 NkDKeAQ8MzgpRtH80v5cxNtdnVLw8+yLToIOKa9Fk44xUGUlAjzRc/N+F423u/jgac zuQYZjBJXc+Rw== Date: Mon, 15 Mar 2021 10:09:42 -0700 From: Jakub Kicinski To: Vasily Averin Cc: cgroups@vger.kernel.org, Michal Hocko , linux-mm@kvack.org, Johannes Weiner , Vladimir Davydov , Shakeel Butt , "David S. Miller" , Hideaki YOSHIFUJI , David Ahern Subject: Re: [PATCH v2 1/8] memcg: accounting for fib6_nodes cache Message-ID: <20210315100942.3cc98bb4@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> In-Reply-To: <85b5f428-294b-af57-f496-5be5fddeeeea@virtuozzo.com> References: <85b5f428-294b-af57-f496-5be5fddeeeea@virtuozzo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: 9sju64afuppapfdmt4nqmagftb7ofp39 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 46F6C601EB4F Received-SPF: none (kernel.org>: No applicable sender policy available) receiver=imf09; identity=mailfrom; envelope-from=""; helo=mail.kernel.org; client-ip=198.145.29.99 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1615828189-432763 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, 15 Mar 2021 15:23:00 +0300 Vasily Averin wrote: > An untrusted netadmin inside a memcg-limited container can create a > huge number of routing entries. Currently, allocated kernel objects > are not accounted to proper memcg, so this can lead to global memory > shortage on the host and cause lot of OOM kiils. > > One such object is the 'struct fib6_node' mostly allocated in > net/ipv6/route.c::__ip6_ins_rt() inside the lock_bh()/unlock_bh() section: > > write_lock_bh(&table->tb6_lock); > err = fib6_add(&table->tb6_root, rt, info, mxc); > write_unlock_bh(&table->tb6_lock); > > It this case is not enough to simply add SLAB_ACCOUNT to corresponding > kmem cache. The proper memory cgroup still cannot be found due to the > incorrect 'in_interrupt()' check used in memcg_kmem_bypass(). > To be sure that caller is not executed in process contxt > '!in_task()' check should be used instead Sorry for a random question, I didn't get the cover letter. What's the overhead of adding SLAB_ACCOUNT? Please make sure you CC netdev on series which may impact networking.