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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 E2F29C282CB for ; Mon, 28 Jan 2019 08:57:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B231C2148E for ; Mon, 28 Jan 2019 08:57:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="I/GgodD1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726774AbfA1I5y (ORCPT ); Mon, 28 Jan 2019 03:57:54 -0500 Received: from mail-pg1-f170.google.com ([209.85.215.170]:37013 "EHLO mail-pg1-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726415AbfA1I5x (ORCPT ); Mon, 28 Jan 2019 03:57:53 -0500 Received: by mail-pg1-f170.google.com with SMTP id c25so6950932pgb.4 for ; Mon, 28 Jan 2019 00:57:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:mime-version:content-disposition :user-agent; bh=uZu38z+wzt4MiIXwa4PXP7mXqfkMRkf2m6SXAtjxH5s=; b=I/GgodD1p7GkwbS38CJdFZtRhnA/gQJgwEdTEX+h3v/iYnYepKNuRcEg+XuhrrlzN8 cWsffD/fgEI07I0vaQFPw1lIOeiLeJX2YDq/ooKsgH/fD6gtv3/IvDmyWCqGgM/UTzfx ouGsHqCriBpnWVr1PXMpy0+ETvxaSgg+vBz6ffifRRaUOXIBH2Iv4I0BhEuon8drMP4N hGp3HZ1jNmyn1WhWGQTLppAEKzS6UBI8vG76NY9AkpBheHXYRvpwaL1OmcXT25i5G4By 8ps/OGFt6cdW5qcvNGiG2q0pixCdTT6qyKgiE0w4zrZNlH2sllUjYUyfNLo3U+EjQWWd k0Pw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition:user-agent; bh=uZu38z+wzt4MiIXwa4PXP7mXqfkMRkf2m6SXAtjxH5s=; b=rYQORAnBKWx8qBc1389/iLiulKWd9190FwTVzkOMdgyctpVTCe7KpGDnVrqPXn7xus YZwH2KnZ78Zg8KBCG1Y6x9PqWEWqGXRarYQwHQLyzkD3m7FA5KdFO8sF74togiT8Leuy X7+t/308a1DtIMTzJ0mb6UGDv7FcCckiyjZaImXdI2CL4zSOkW5bcn1AB9AZsptssAVP viq7nJE9I2dYz3/yAqZA6RDGlKMpMAKOAxWof1dxnpJ6Q2apRSMLD600xnPNWv+hxpMs q8VQTuD5TOrlhud/S3Nde0CCM788ucvD/B2kRc0GTmdEmlUplNVw8QanQkhWl3s/ZMrG 3/UA== X-Gm-Message-State: AJcUukemM9DV1h1T5xsbA19NdVinzkPGma6x0sYBJLaB6o/FUjomH7I0 tQbDLIHMlD5HeEwe+85JQMARMeGt X-Google-Smtp-Source: ALg8bN4dzIw3mNaJ5UhDtQ28SrDqnY80U3M444S411lQReHk+JR6PLTdbtkQSMyRrw9JqiNEw4aoEA== X-Received: by 2002:a63:de46:: with SMTP id y6mr19022088pgi.198.1548665872029; Mon, 28 Jan 2019 00:57:52 -0800 (PST) Received: from localhost ([175.223.18.40]) by smtp.gmail.com with ESMTPSA id 202sm41945489pfy.87.2019.01.28.00.57.50 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 28 Jan 2019 00:57:50 -0800 (PST) Date: Mon, 28 Jan 2019 17:57:47 +0900 From: Sergey Senozhatsky To: Michal Hocko , Vlastimil Babka Cc: Tetsuo Handa , Andrew Morton , Johannes Weiner , linux-kernel@vger.kernel.org, linux-mm , Sergey Senozhatsky Subject: [linux-next] kcompactd0 stuck in a CPU-burning loop Message-ID: <20190128085747.GA14454@jagdpanzerIV> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.11.2 (2019-01-07) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, next-20190125 kcompactd0 is spinning on something, burning CPUs in the meantime: %CPU TIME+ COMMAND 100.0 0.0 34:04.20 R [kcompactd0] Not sure I know how to reproduce it; so am probably not going to be a very helpful tester. I tried to ftrace kcompactd0 PID, and I see the same path all over the tracing file: 2) 0.119 us | unlock_page(); 2) 0.109 us | unlock_page(); 2) 0.096 us | compaction_free(); 2) 0.104 us | ___might_sleep(); 2) 0.121 us | compaction_alloc(); 2) 0.111 us | page_mapped(); 2) 0.105 us | page_mapped(); 2) | move_to_new_page() { 2) 0.102 us | page_mapping(); 2) | buffer_migrate_page_norefs() { 2) | __buffer_migrate_page() { 2) | expected_page_refs() { 2) 0.118 us | page_mapping(); 2) 0.321 us | } 2) | __might_sleep() { 2) 0.122 us | ___might_sleep(); 2) 0.332 us | } 2) | _raw_spin_lock() { 2) 0.115 us | preempt_count_add(); 2) 0.321 us | } 2) | _raw_spin_unlock() { 2) 0.114 us | preempt_count_sub(); 2) 0.321 us | } 2) | invalidate_bh_lrus() { 2) | on_each_cpu_cond() { 2) | on_each_cpu_cond_mask() { 2) | __might_sleep() { 2) 0.114 us | ___might_sleep(); 2) 0.316 us | } 2) 0.109 us | preempt_count_add(); 2) 0.128 us | has_bh_in_lru(); 2) 0.105 us | has_bh_in_lru(); 2) 0.124 us | has_bh_in_lru(); 2) 0.103 us | has_bh_in_lru(); 2) 0.125 us | has_bh_in_lru(); 2) 0.105 us | has_bh_in_lru(); 2) 0.123 us | has_bh_in_lru(); 2) 0.107 us | has_bh_in_lru(); 2) | on_each_cpu_mask() { 2) 0.104 us | preempt_count_add(); 2) 0.110 us | smp_call_function_many(); 2) 0.105 us | preempt_count_sub(); 2) 0.764 us | } 2) 0.116 us | preempt_count_sub(); 2) 3.676 us | } 2) 3.889 us | } 2) 4.087 us | } 2) | _raw_spin_lock() { 2) 0.112 us | preempt_count_add(); 2) 0.315 us | } 2) | _raw_spin_unlock() { 2) 0.108 us | preempt_count_sub(); 2) 0.309 us | } 2) | unlock_buffer() { 2) | wake_up_bit() { 2) 0.118 us | __wake_up_bit(); 2) 0.317 us | } 2) 0.513 us | } 2) 7.440 us | } 2) 7.643 us | } 2) 8.070 us | } PG migration fails a lot: pgmigrate_success 111063 pgmigrate_fail 269841559 compact_migrate_scanned 536253365 compact_free_scanned 360889 compact_isolated 270072733 compact_stall 0 compact_fail 0 compact_success 0 compact_daemon_wake 56 compact_daemon_migrate_scanned 536253365 compact_daemon_free_scanned 360889 Let me know if I can help with anything else. I'll keep the the box alive for a while, but will have to power it off eventually. -ss