From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759800AbcDMHab (ORCPT ); Wed, 13 Apr 2016 03:30:31 -0400 Received: from terminus.zytor.com ([198.137.202.10]:51402 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759782AbcDMHa3 (ORCPT ); Wed, 13 Apr 2016 03:30:29 -0400 Date: Wed, 13 Apr 2016 00:29:46 -0700 From: tip-bot for Davidlohr Bueso Message-ID: Cc: peterz@infradead.org, akpm@linux-foundation.org, hpa@zytor.com, dave@stgolabs.net, tglx@linutronix.de, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, dbueso@suse.de, mingo@kernel.org, paulmck@linux.vnet.ibm.com Reply-To: torvalds@linux-foundation.org, dbueso@suse.de, linux-kernel@vger.kernel.org, tglx@linutronix.de, paulmck@linux.vnet.ibm.com, mingo@kernel.org, dave@stgolabs.net, peterz@infradead.org, hpa@zytor.com, akpm@linux-foundation.org In-Reply-To: <1460476375-27803-7-git-send-email-paulmck@linux.vnet.ibm.com> References: <1460476375-27803-7-git-send-email-paulmck@linux.vnet.ibm.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:locking/core] locking/Documentation: Mention smp_cond_acquire() Git-Commit-ID: 787df6383caa1338a4f6640d71917bc2d8c068b1 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: 787df6383caa1338a4f6640d71917bc2d8c068b1 Gitweb: http://git.kernel.org/tip/787df6383caa1338a4f6640d71917bc2d8c068b1 Author: Davidlohr Bueso AuthorDate: Tue, 12 Apr 2016 08:52:55 -0700 Committer: Ingo Molnar CommitDate: Wed, 13 Apr 2016 08:52:23 +0200 locking/Documentation: Mention smp_cond_acquire() ... do this next to smp_load_acquire() when first mentioning ACQUIRE. While this call is briefly explained and control dependencies are mentioned later, it does not hurt the reader. Signed-off-by: Davidlohr Bueso Signed-off-by: Paul E. McKenney Cc: Andrew Morton Cc: Davidlohr Bueso Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: bobby.prani@gmail.com Cc: dhowells@redhat.com Cc: dipankar@in.ibm.com Cc: dvhart@linux.intel.com Cc: edumazet@google.com Cc: fweisbec@gmail.com Cc: jiangshanlai@gmail.com Cc: josh@joshtriplett.org Cc: mathieu.desnoyers@efficios.com Cc: oleg@redhat.com Cc: rostedt@goodmis.org Link: http://lkml.kernel.org/r/1460476375-27803-7-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- Documentation/memory-barriers.txt | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt index 7133626..a9454b1 100644 --- a/Documentation/memory-barriers.txt +++ b/Documentation/memory-barriers.txt @@ -431,8 +431,9 @@ And a couple of implicit varieties: This acts as a one-way permeable barrier. It guarantees that all memory operations after the ACQUIRE operation will appear to happen after the ACQUIRE operation with respect to the other components of the system. - ACQUIRE operations include LOCK operations and smp_load_acquire() - operations. + ACQUIRE operations include LOCK operations and both smp_load_acquire() + and smp_cond_acquire() operations. The later builds the necessary ACQUIRE + semantics from relying on a control dependency and smp_rmb(). Memory operations that occur before an ACQUIRE operation may appear to happen after it completes.