From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with ESMTP id D56946B00EE for ; Tue, 25 Jan 2011 12:59:14 -0500 (EST) Message-Id: <20110125174907.890366530@chello.nl> Date: Tue, 25 Jan 2011 18:31:24 +0100 From: Peter Zijlstra Subject: [PATCH 13/25] mutex: Provide mutex_is_contended References: <20110125173111.720927511@chello.nl> Content-Disposition: inline; filename=peter_zijlstra-mutex-provide_mutex_is_contended.patch Sender: owner-linux-mm@kvack.org To: Andrea Arcangeli , Avi Kivity , Thomas Gleixner , Rik van Riel , Ingo Molnar , akpm@linux-foundation.org, Linus Torvalds Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, Benjamin Herrenschmidt , David Miller , Hugh Dickins , Mel Gorman , Nick Piggin , Peter Zijlstra , Paul McKenney , Yanmin Zhang List-ID: Usable for lock-breaks and such. Reviewed-by: KAMEZAWA Hiroyuki Signed-off-by: Peter Zijlstra --- include/linux/mutex.h | 5 +++++ 1 file changed, 5 insertions(+) Index: linux-2.6/include/linux/mutex.h =================================================================== --- linux-2.6.orig/include/linux/mutex.h +++ linux-2.6/include/linux/mutex.h @@ -126,6 +126,11 @@ static inline int mutex_is_locked(struct return atomic_read(&lock->count) != 1; } +static inline int mutex_is_contended(struct mutex *lock) +{ + return atomic_read(&lock->count) < 0; +} + /* * See kernel/mutex.c for detailed documentation of these APIs. * Also see Documentation/mutex-design.txt. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org