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=-12.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 5B7DDC4346E for ; Sun, 27 Sep 2020 16:11:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 13281221E5 for ; Sun, 27 Sep 2020 16:11:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=bytedance-com.20150623.gappssmtp.com header.i=@bytedance-com.20150623.gappssmtp.com header.b="gAi4S4k0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726415AbgI0QLp (ORCPT ); Sun, 27 Sep 2020 12:11:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60314 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726303AbgI0QLp (ORCPT ); Sun, 27 Sep 2020 12:11:45 -0400 Received: from mail-pj1-x1044.google.com (mail-pj1-x1044.google.com [IPv6:2607:f8b0:4864:20::1044]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2D1DAC0613CE for ; Sun, 27 Sep 2020 09:11:45 -0700 (PDT) Received: by mail-pj1-x1044.google.com with SMTP id mn7so2198845pjb.5 for ; Sun, 27 Sep 2020 09:11:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=ovlhZsWFZPQTrCZro69WC5buXFc9ezGOhnSX1p1upZ4=; b=gAi4S4k0nB7OSuwiuXf0Xf8d6SLcqL2ICHuNqi7xVtUjD4hLwrM4HyC6wXONIvbJ12 qAsClUfcIWDiUiznhwlHablwVf3IaopjrBxaE5lPmVhdSLK0XbA9+e4Nv0t4DKMq2Uu+ fSkPGonQlj5qdq9HvoEWphdrlmDikIwQR+WlGqb/n7v9Wi/3tyJczfLPDl0Yin+8I1Hy 4HYyOar7tz6n3x/0lldYZALc2WQI+tWyrKC61G+XdvJGYebHnjGtBvjb87xlQ2jFJ3ob Xhl+rd+V7jGRjghcFJfv1WKzK1C3tjPWZ6IurvxtDyOEg4aXkFx4Mz1rljiu46k16O3W j9QA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=ovlhZsWFZPQTrCZro69WC5buXFc9ezGOhnSX1p1upZ4=; b=q4Qan5JKAWXr/M5jgZK46xgLO7awboMU6F1EXZsEtid04qBCop9CVmLnOYh3yuqwPq Kd8r2FREEuc1GyhvMu/4FwgcRRV4GdXuWm3/qb0AUxGVMvkMMnvx9ww37GlXBj+cq52v jCX96y7fbIF1fQKaeH6WDEaX+a9pDMVpaJcntdS/TYn9PZqOFu/znAVGzdHH1eEAquko Cmq1nmRAahoM9+hVqCeXMMtWJtzfiTnVqm8MGOilvGQ0SYuKeamGdQub/eg+XUhbs6ci ajVRcUvwrHK4fy9MAwWdn/+a1dxCF/VbLQvvKO3OKEe/4j49sDR4qlyyhW1bCFlFktGY iAfg== X-Gm-Message-State: AOAM532BTEJaZV6LcjKf70EA4KJlpTQ4arBZxqvyvQosnzViDTR1XkDQ x0AnGYeGVMixO4d8FQR9nFrjXlEzTLZ8TQ== X-Google-Smtp-Source: ABdhPJzzFGf3ea0dQ+SGuxATz2ZYqbvd3Tork6B94o+zB+s7A/6vmdl3p2yzbDm/Iq1gwhxISwdogg== X-Received: by 2002:a17:902:7b93:b029:d2:172:7d9e with SMTP id w19-20020a1709027b93b02900d201727d9emr7982053pll.83.1601223104517; Sun, 27 Sep 2020 09:11:44 -0700 (PDT) Received: from localhost.localdomain ([103.136.220.70]) by smtp.gmail.com with ESMTPSA id l141sm8784844pfd.47.2020.09.27.09.11.39 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sun, 27 Sep 2020 09:11:43 -0700 (PDT) From: Chengming Zhou To: linux-kernel@vger.kernel.org, pmladek@suse.com, sergey.senozhatsky@gmail.com, rostedt@goodmis.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, bsegall@google.com, mgorman@suse.de Cc: zhouchengming@bytedance.com, songmuchun@bytedance.com Subject: [PATCH 2/2] sched: mark PRINTK_DEFERRED_CONTEXT_MASK in __schedule() Date: Mon, 28 Sep 2020 00:11:30 +0800 Message-Id: <20200927161130.33172-2-zhouchengming@bytedance.com> X-Mailer: git-send-email 2.24.3 (Apple Git-128) In-Reply-To: <20200927161130.33172-1-zhouchengming@bytedance.com> References: <20200927161130.33172-1-zhouchengming@bytedance.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The WARN_ON/WARN_ON_ONCE with rq lock held in __schedule() should be deferred by marking the PRINTK_DEFERRED_CONTEXT_MASK, or will cause deadlock on rq lock in the printk path. Signed-off-by: Chengming Zhou Signed-off-by: Muchun Song --- kernel/sched/core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 2d95dc3f4644..81d8bf614225 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4444,6 +4444,7 @@ static void __sched notrace __schedule(bool preempt) */ rq_lock(rq, &rf); smp_mb__after_spinlock(); + printk_deferred_enter(); /* Promote REQ to ACT */ rq->clock_update_flags <<= 1; @@ -4530,6 +4531,7 @@ static void __sched notrace __schedule(bool preempt) rq_unlock_irq(rq, &rf); } + printk_deferred_exit(); balance_callback(rq); } -- 2.11.0