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=-7.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 B549DC433DF for ; Tue, 21 Jul 2020 16:20:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9450F20771 for ; Tue, 21 Jul 2020 16:20:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="paVwZZrE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728462AbgGUQUP (ORCPT ); Tue, 21 Jul 2020 12:20:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43364 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728127AbgGUQUP (ORCPT ); Tue, 21 Jul 2020 12:20:15 -0400 Received: from mail-lf1-x144.google.com (mail-lf1-x144.google.com [IPv6:2a00:1450:4864:20::144]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB8A8C061794; Tue, 21 Jul 2020 09:20:14 -0700 (PDT) Received: by mail-lf1-x144.google.com with SMTP id o4so12012040lfi.7; Tue, 21 Jul 2020 09:20:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Groro3SyYJWphwceTkpNDYDrIfmBoLsMEqqiSFl6lVU=; b=paVwZZrESP/VwnUw67pGD0aF7K2NqOxjCGIe6FZvasfd6FTb2J2XEc1NEgGIBdSL0p FnckrJY3O/5lscjH+s3g8IrlzM9MiMo/kL8CuZgdBFpCTSLPmF9LYgkDEA1+evUHw6U5 YjdqDQ1xpDAapf6UfWYP8pmjvniRgerQj7DKxl8nFGtYCu+CzX55iMwGi0dWmnySMKZ6 czWiT78D8F1Xh2Bac4wjwqwEFqxyZZULs9x7GycAqoSAbCarNdbZHlIILiMdeCF471+G X5EO2m3CKLKL5K6hKLu9zuvhwbdwlcJ5stgwoFWBJVJiGcqW8k03FFxoMuQ1vRkNpma5 DXWw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Groro3SyYJWphwceTkpNDYDrIfmBoLsMEqqiSFl6lVU=; b=eGHW4xzD9ckdhSgHkX+9N34VB3SvEF8SBmfrSsRiQtdZ4v1HF6+NnN1j1c1O8Fei8j U7FOveODKl/006mUTlRONjo1yciPDW/qI6/KJ1erFoPDw1nhnke3t028duTR+k8D9Pm4 vwA0DK0hQg3RyTP3o5sTk4cxLfh3lXMPLWPotn2WPN15cNlhqp/jXUnfgKQ/E54gCYaE cVGhgUWkgXaEZLrEgN9IcUhEC8b0OWzBR/o63fe7e6Pvy7Qf1wQYEb0mi1wO2QmcrCgN adrds9g4RN5axnRZzNhtP8+iZqgElpaGO1MS1EMjgSL5jVkRkzffKX5r52PAmph+h2sP gTdg== X-Gm-Message-State: AOAM533ZFjZuOGlbzvv6VVLFLinLVQ+VEk3T/DH+0Zzk5JtOo35Awulr AiEQ7qx7KWiLyaRuXwBwASuKZa9ZsXs1ytZOcBs= X-Google-Smtp-Source: ABdhPJyHb2JLW+ucwR3k91mAjb0EzCI+hZk+2d8O0FCv8vZTJgInB7YdK5zllSk2E9C0igvRMz5oQ/poDvXl5QrHIyg= X-Received: by 2002:a19:815:: with SMTP id 21mr13598099lfi.119.1595348413371; Tue, 21 Jul 2020 09:20:13 -0700 (PDT) MIME-Version: 1.0 References: <87zh7tw4dh.fsf@cloudflare.com> In-Reply-To: <87zh7tw4dh.fsf@cloudflare.com> From: Alexei Starovoitov Date: Tue, 21 Jul 2020 09:20:02 -0700 Message-ID: Subject: Re: [PATCH bpf-next] bpf: cpumap: fix possible rcpu kthread hung To: Jakub Sitnicki Cc: Lorenzo Bianconi , Network Development , bpf , "David S. Miller" , Alexei Starovoitov , Jesper Dangaard Brouer , Daniel Borkmann , lorenzo.bianconi@redhat.com, Jakub Kicinski Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, Jul 21, 2020 at 3:26 AM Jakub Sitnicki wrote: > > On Sun, Jul 19, 2020 at 05:52 PM CEST, Lorenzo Bianconi wrote: > > Fix the following cpumap kthread hung. The issue is currently occurring > > when __cpu_map_load_bpf_program fails (e.g if the bpf prog has not > > BPF_XDP_CPUMAP as expected_attach_type) > > > > $./test_progs -n 101 > > 101/1 cpumap_with_progs:OK > > 101 xdp_cpumap_attach:OK > > Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED > > [ 369.996478] INFO: task cpumap/0/map:7:205 blocked for more than 122 seconds. > > [ 369.998463] Not tainted 5.8.0-rc4-01472-ge57892f50a07 #212 > > [ 370.000102] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > > [ 370.001918] cpumap/0/map:7 D 0 205 2 0x00004000 > > [ 370.003228] Call Trace: > > [ 370.003930] __schedule+0x5c7/0xf50 > > [ 370.004901] ? io_schedule_timeout+0xb0/0xb0 > > [ 370.005934] ? static_obj+0x31/0x80 > > [ 370.006788] ? mark_held_locks+0x24/0x90 > > [ 370.007752] ? cpu_map_bpf_prog_run_xdp+0x6c0/0x6c0 > > [ 370.008930] schedule+0x6f/0x160 > > [ 370.009728] schedule_preempt_disabled+0x14/0x20 > > [ 370.010829] kthread+0x17b/0x240 > > [ 370.011433] ? kthread_create_worker_on_cpu+0xd0/0xd0 > > [ 370.011944] ret_from_fork+0x1f/0x30 > > [ 370.012348] > > Showing all locks held in the system: > > [ 370.013025] 1 lock held by khungtaskd/33: > > [ 370.013432] #0: ffffffff82b24720 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x28/0x1c3 > > > > [ 370.014461] ============================================= > > > > Fixes: 9216477449f3 ("bpf: cpumap: Add the possibility to attach an eBPF program to cpumap") > > Reported-by: Jakub Sitnicki > > Signed-off-by: Lorenzo Bianconi > > --- > > Tested-by: Jakub Sitnicki > Reviewed-by: Jakub Sitnicki Applied. Thanks