From patchwork Fri Jan 15 18:30:29 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 568398 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 724D71401DA; Sat, 16 Jan 2016 05:32:55 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1aK9B6-0002Xr-7M; Fri, 15 Jan 2016 18:32:52 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1aK98r-0001Q6-T6 for kernel-team@lists.ubuntu.com; Fri, 15 Jan 2016 18:30:33 +0000 Received: from 1.general.kamal.us.vpn ([10.172.68.52] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1aK98r-0001yy-8c; Fri, 15 Jan 2016 18:30:33 +0000 Received: from kamal by fourier with local (Exim 4.82) (envelope-from ) id 1aK98o-0004oA-Fq; Fri, 15 Jan 2016 10:30:30 -0800 From: Kamal Mostafa To: Sasha Levin Subject: [4.2.y-ckt stable] Patch "sched/core: Remove false-positive warning from wake_up_process()" has been added to staging queue Date: Fri, 15 Jan 2016 10:30:29 -0800 Message-Id: <1452882629-18452-1-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 X-Extended-Stable: 4.2 Cc: "Peter Zijlstra \(Intel\)" , Kamal Mostafa , Mike Galbraith , oleg@redhat.com, kernel-team@lists.ubuntu.com, Thomas Gleixner , Linus Torvalds , Ingo Molnar X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com This is a note to let you know that I have just added a patch titled sched/core: Remove false-positive warning from wake_up_process() to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue This patch is scheduled to be released in version 4.2.8-ckt2. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 4.2.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ---8<------------------------------------------------------------ From 026bffe7be89a26bf6b50195d1185264bd35d68e Mon Sep 17 00:00:00 2001 From: Sasha Levin Date: Mon, 30 Nov 2015 20:34:20 -0500 Subject: sched/core: Remove false-positive warning from wake_up_process() commit 119d6f6a3be8b424b200dcee56e74484d5445f7e upstream. Because wakeups can (fundamentally) be late, a task might not be in the expected state. Therefore testing against a task's state is racy, and can yield false positives. Signed-off-by: Sasha Levin Signed-off-by: Peter Zijlstra (Intel) Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: oleg@redhat.com Fixes: 9067ac85d533 ("wake_up_process() should be never used to wakeup a TASK_STOPPED/TRACED task") Link: http://lkml.kernel.org/r/1448933660-23082-1-git-send-email-sasha.levin@oracle.com Signed-off-by: Ingo Molnar Signed-off-by: Kamal Mostafa --- kernel/sched/core.c | 1 - 1 file changed, 1 deletion(-) -- 1.9.1 diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 87c3bb8..99cc1f4 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1972,7 +1972,6 @@ out: */ int wake_up_process(struct task_struct *p) { - WARN_ON(task_is_stopped_or_traced(p)); return try_to_wake_up(p, TASK_NORMAL, 0); } EXPORT_SYMBOL(wake_up_process);