From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753288AbbJFQSd (ORCPT ); Tue, 6 Oct 2015 12:18:33 -0400 Received: from terminus.zytor.com ([198.137.202.10]:34837 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752196AbbJFQSa (ORCPT ); Tue, 6 Oct 2015 12:18:30 -0400 Date: Tue, 6 Oct 2015 09:17:45 -0700 From: tip-bot for Geliang Tang Message-ID: Cc: efault@gmx.de, peterz@infradead.org, hpa@zytor.com, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, geliangtang@163.com, mingo@kernel.org, tglx@linutronix.de Reply-To: geliangtang@163.com, mingo@kernel.org, tglx@linutronix.de, hpa@zytor.com, efault@gmx.de, peterz@infradead.org, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org In-Reply-To: <6fa7125979f98bbeac26e268271769b6ca935c8d.1444051018.git.geliangtang@163.com> References: <6fa7125979f98bbeac26e268271769b6ca935c8d.1444051018.git.geliangtang@163.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched/core: Drop unlikely behind BUG_ON() Git-Commit-ID: ce03e4137bb22fc560ad7a07cf4138ae2cd59f65 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: ce03e4137bb22fc560ad7a07cf4138ae2cd59f65 Gitweb: http://git.kernel.org/tip/ce03e4137bb22fc560ad7a07cf4138ae2cd59f65 Author: Geliang Tang AuthorDate: Mon, 5 Oct 2015 21:26:05 +0800 Committer: Ingo Molnar CommitDate: Tue, 6 Oct 2015 17:08:22 +0200 sched/core: Drop unlikely behind BUG_ON() (1) For !CONFIG_BUG cases, the bug call is a no-op, so we couldn't care less and the change is ok. (2) PPC and MIPS, which HAVE_ARCH_BUG_ON, do not rely on branch predictions as it seems to be pointless [1] and thus callers should not be trying to push an optimization in the first place. (3) For CONFIG_BUG and !HAVE_ARCH_BUG_ON cases, BUG_ON() contains an unlikely compiler flag already. Hence, we can drop unlikely behind BUG_ON(). [1] http://lkml.iu.edu/hypermail/linux/kernel/1101.3/02289.html Signed-off-by: Geliang Tang Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/6fa7125979f98bbeac26e268271769b6ca935c8d.1444051018.git.geliangtang@163.com Signed-off-by: Ingo Molnar --- kernel/sched/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index fb14a01..a395db1 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2971,7 +2971,7 @@ static noinline void __schedule_bug(struct task_struct *prev) static inline void schedule_debug(struct task_struct *prev) { #ifdef CONFIG_SCHED_STACK_END_CHECK - BUG_ON(unlikely(task_stack_end_corrupted(prev))); + BUG_ON(task_stack_end_corrupted(prev)); #endif if (unlikely(in_atomic_preempt_off())) {