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=-12.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 64F24C43387 for ; Tue, 18 Dec 2018 20:40:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3C8542184C for ; Tue, 18 Dec 2018 20:40:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727130AbeLRUki convert rfc822-to-8bit (ORCPT ); Tue, 18 Dec 2018 15:40:38 -0500 Received: from mail.kernel.org ([198.145.29.99]:33182 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726981AbeLRUkh (ORCPT ); Tue, 18 Dec 2018 15:40:37 -0500 Received: from gandalf.local.home (cpe-66-24-56-78.stny.res.rr.com [66.24.56.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 871A9217D9; Tue, 18 Dec 2018 20:40:36 +0000 (UTC) Date: Tue, 18 Dec 2018 15:40:34 -0500 From: Steven Rostedt To: LKML , linux-rt-users Cc: Thomas Gleixner , Carsten Emde , John Kacur , Sebastian Andrzej Siewior , Julia Cartwright , Daniel Wagner , Tom Zanussi Subject: [ANNOUNCE] 4.14.87-rt49 Message-ID: <20181218154034.612d729d@gandalf.local.home> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Dear RT Folks, I'm pleased to announce the 4.14.87-rt49 stable release. Sorry for taking so long, I've just been swamped (like everyone else) *** PLEASE NOTE *** This release is **NOT** just an update to the new stable 4.14.87 version as there was a small RT specific change that has been made. I had to make an update to handle a backport of adding preempt_disable() around the console_unlock() code. That patch is below. You can get this release via the git tree at: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git branch: v4.14-rt Head SHA1: c3fb62599cb0bf9ea0223433ccf7c0c37056c392 Or to build 4.14.87-rt49 directly, the following patches should be applied: http://www.kernel.org/pub/linux/kernel/v4.x/linux-4.14.tar.xz http://www.kernel.org/pub/linux/kernel/v4.x/patch-4.14.87.xz http://www.kernel.org/pub/linux/kernel/projects/rt/4.14/patch-4.14.87-rt49.patch.xz Enjoy, -- Steve >From 0ab3459b0a8b8d19054aa813611c8dc22ce04af8 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Fri, 14 Dec 2018 21:36:55 -0500 Subject: [PATCH] printk: Do not disable preemption when calling consoles in RT console_unlock() may call consoles that call spin_lock(), where spin_lock is a mutex in PREEMPT_RT. Although mainline may be worried about preempted holders of the console lock from preventing printk() output, the RT kernel does not. Use migrate_disable() to disable preemption when !RT, but we really don't care if the task stays on the CPU or not for RT. It just has to be able to schedule. Signed-off-by: Steven Rostedt (VMware) --- kernel/printk/printk.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 8a7c4f79fca0..029ae3caa80e 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -1811,7 +1811,7 @@ asmlinkage int vprintk_emit(int facility, int level, * console_sem which would prevent anyone from printing to * console */ - preempt_disable(); + migrate_disable(); /* * Try to acquire and then immediately release the console * semaphore. The release will print out buffers and wake up @@ -1819,7 +1819,7 @@ asmlinkage int vprintk_emit(int facility, int level, */ if (may_trylock && console_trylock()) console_unlock(); - preempt_enable(); + migrate_enable(); } return printed_len; -- 2.19.2