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=-5.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 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 144E6C1975A for ; Thu, 12 Mar 2020 14:03:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DEA71206E7 for ; Thu, 12 Mar 2020 14:03:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lca.pw header.i=@lca.pw header.b="ID3zIu4I" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727496AbgCLODh (ORCPT ); Thu, 12 Mar 2020 10:03:37 -0400 Received: from mail-qk1-f196.google.com ([209.85.222.196]:39573 "EHLO mail-qk1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727451AbgCLODg (ORCPT ); Thu, 12 Mar 2020 10:03:36 -0400 Received: by mail-qk1-f196.google.com with SMTP id e16so6298150qkl.6 for ; Thu, 12 Mar 2020 07:03:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lca.pw; s=google; h=message-id:subject:from:to:cc:date:in-reply-to:references :mime-version:content-transfer-encoding; bh=llnqGMEP0WhestZ7Ck/j/TXED0wzZ+R7hJNKQAMFwSw=; b=ID3zIu4I4SYuh3dOvdboHzfUp3zrBkMZ78ALde5G9suHbGgxzk14dfh6HX6hcn9Wna R4ATKeTZ0UR88ii+B9cp/1mPaYzSAC5G9EeUbljITfIR+vL15CV2FxSBDzHfsJsOf/K/ 8II7onlt8fLcH04pHDA7OfApc7ziQMikZIPDK1Eh2hhcP5cZ2Ltqn5W7guqO0bcw92Dy UoJ8pBBedDvQJJp7uMwIBFXs1WdRqOHXknP4GZvozHABqttvVfrD9XUwXuTWJWsMqmP9 X5y4lDZKcLxXW/j7o/6fhQOpzl03B5NLKJ+fTJBx7IBEqQerGIPB0/9zM36V2y5Yqgo3 cweQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:mime-version:content-transfer-encoding; bh=llnqGMEP0WhestZ7Ck/j/TXED0wzZ+R7hJNKQAMFwSw=; b=a9glYjlVNA7zQLSr4NH5IHtSFCbBtFS6jiAvfT46QYlC3rwcu7WRZ/w3kUeAQX6E7Y pahTOfUjfZ7Tj+zsH1OXlfDnDaxPTEmYs4acW+m7QHnTFFLoO+aBv2Q2pNvZJ+TjT8sk 0wcqpdYe9USQpHbjkw8rJuZkMFT2Ujs4o7Wo0e7CndVGevuKOc9GixoAh3MJ9OxdYAcU AodIOFCSo0KpsjryJsl1bGNHlyPYCIuOMWsgmVrwPQ2h5jatsxFMRRnQ7iKyQFT1h1pf w2XS4XbFuXRq7lsBiJ5KsrH+0yYVi7xrdKgfE43STMc8470+oxZqkqEG2FqPJz+1dU45 hvBA== X-Gm-Message-State: ANhLgQ3cURMY05b+5e8nIIo2phDytDFLb2h9gUIiRwEedxFHC4tjNDoR N4x+sNFcdjjSYeUDI7OcVGzZ0A== X-Google-Smtp-Source: ADFU+vsttBVJyaFPAv/6+uT5X/zUbwGQzRZzYpJbEOkSBPOQimT0W9lYBi/8o5HSNH3mjdxwoqUFkg== X-Received: by 2002:a37:4cc3:: with SMTP id z186mr7646916qka.69.1584021813971; Thu, 12 Mar 2020 07:03:33 -0700 (PDT) Received: from dhcp-41-57.bos.redhat.com (nat-pool-bos-t.redhat.com. [66.187.233.206]) by smtp.gmail.com with ESMTPSA id j85sm12186207qke.20.2020.03.12.07.03.32 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 12 Mar 2020 07:03:33 -0700 (PDT) Message-ID: <1584021811.7365.180.camel@lca.pw> Subject: Re: [PATCH v4 2/2] net: memcg: late association of sock to memcg From: Qian Cai To: Shakeel Butt , Eric Dumazet , Roman Gushchin Cc: Johannes Weiner , Michal Hocko , Greg Thelen , Andrew Morton , "David S . Miller" , Alexey Kuznetsov , Hideaki YOSHIFUJI , netdev@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Date: Thu, 12 Mar 2020 10:03:31 -0400 In-Reply-To: <20200310051606.33121-2-shakeelb@google.com> References: <20200310051606.33121-1-shakeelb@google.com> <20200310051606.33121-2-shakeelb@google.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6 (3.22.6-10.el7) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, 2020-03-09 at 22:16 -0700, Shakeel Butt wrote: > diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c > index a4db79b1b643..65a3b2565102 100644 > --- a/net/ipv4/inet_connection_sock.c > +++ b/net/ipv4/inet_connection_sock.c > @@ -482,6 +482,26 @@ struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern) > } > spin_unlock_bh(&queue->fastopenq.lock); > } > + > + if (mem_cgroup_sockets_enabled) { > + int amt; > + > + /* atomically get the memory usage, set and charge the > + * sk->sk_memcg. > + */ > + lock_sock(newsk); Here we have a deadlock, [  362.620977][ T4106] WARNING: possible recursive locking detected [  362.626983][ T4106] 5.6.0-rc5-next-20200312+ #5 Tainted: G             L    [  362.633941][ T4106] -------------------------------------------- [  362.639944][ T4106] sshd/4106 is trying to acquire lock: [  362.645251][ T4106] 7bff008a2eae6330 (sk_lock-AF_INET){+.+.}, at: inet_csk_accept+0x370/0x45c inet_csk_accept at net/ipv4/inet_connection_sock.c:497 [  362.653791][ T4106]  [  362.653791][ T4106] but task is already holding lock: [  362.661007][ T4106] c0ff008a2eae9430 (sk_lock-AF_INET){+.+.}, at: inet_csk_accept+0x48/0x45c inet_csk_accept at net/ipv4/inet_connection_sock.c:451 [  362.669452][ T4106]  [  362.669452][ T4106] other info that might help us debug this: [  362.677364][ T4106]  Possible unsafe locking scenario: [  362.677364][ T4106]  [  362.684666][ T4106]        CPU0 [  362.687801][ T4106]        ---- [  362.690937][ T4106]   lock(sk_lock-AF_INET); [  362.695204][ T4106]   lock(sk_lock-AF_INET); [  362.699472][ T4106]  [  362.699472][ T4106]  *** DEADLOCK *** [  362.699472][ T4106]  [  362.707469][ T4106]  May be due to missing lock nesting notation [  362.707469][ T4106]  [  362.715643][ T4106] 1 lock held by sshd/4106: [  362.719993][ T4106]  #0: c0ff008a2eae9430 (sk_lock-AF_INET){+.+.}, at: inet_csk_accept+0x48/0x45c [  362.728874][ T4106]  [  362.728874][ T4106] stack backtrace: [  362.734622][ T4106] CPU: 22 PID: 4106 Comm: sshd Tainted: G             L    5.6.0-rc5-next-20200312+ #5 [  362.744096][ T4106] Hardware name: HPE Apollo 70             /C01_APACHE_MB         , BIOS L50_5.13_1.11 06/18/2019 [  362.754525][ T4106] Call trace: [  362.757667][ T4106]  dump_backtrace+0x0/0x2c8 [  362.762022][ T4106]  show_stack+0x20/0x2c [  362.766032][ T4106]  dump_stack+0xe8/0x150 [  362.770128][ T4106]  validate_chain+0x2f08/0x35e0 [  362.774830][ T4106]  __lock_acquire+0x868/0xc2c [  362.779358][ T4106]  lock_acquire+0x320/0x360 [  362.783715][ T4106]  lock_sock_nested+0x9c/0xd8 [  362.788243][ T4106]  inet_csk_accept+0x370/0x45c [  362.792861][ T4106]  inet_accept+0x80/0x1cc [  362.797045][ T4106]  __sys_accept4_file+0x1b0/0x2bc [  362.801921][ T4106]  __arm64_sys_accept+0x74/0xc8 [  362.806625][ T4106]  do_el0_svc+0x170/0x240 [  362.810807][ T4106]  el0_sync_handler+0x150/0x250 [  362.815509][ T4106]  el0_sync+0x164/0x180 > + > + /* The sk has not been accepted yet, no need to look at > + * sk->sk_wmem_queued. > + */ > + amt = sk_mem_pages(newsk->sk_forward_alloc + > + atomic_read(&sk->sk_rmem_alloc)); > + mem_cgroup_sk_alloc(newsk); > + if (newsk->sk_memcg && amt) > + mem_cgroup_charge_skmem(newsk->sk_memcg, amt); > + > + release_sock(newsk); > + } > out: > release_sock(sk); > if (req)