From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756210Ab3LDWrN (ORCPT ); Wed, 4 Dec 2013 17:47:13 -0500 Received: from e34.co.us.ibm.com ([32.97.110.152]:59772 "EHLO e34.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756178Ab3LDWrH (ORCPT ); Wed, 4 Dec 2013 17:47:07 -0500 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@kernel.org, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, darren@dvhart.com, fweisbec@gmail.com, sbw@mit.edu, "Paul E. McKenney" Subject: [PATCH tip/core/locking 2/4] Documentation/memory-barriers.txt: Add long atomic examples to memory-barriers.txt Date: Wed, 4 Dec 2013 14:46:57 -0800 Message-Id: <1386197219-31964-2-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.1.5 In-Reply-To: <1386197219-31964-1-git-send-email-paulmck@linux.vnet.ibm.com> References: <20131204224628.GA30159@linux.vnet.ibm.com> <1386197219-31964-1-git-send-email-paulmck@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13120422-1542-0000-0000-000003E9086D Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Paul E. McKenney" Although the atomic_long_t functions are quite useful, they are a bit obscure. This commit therefore adds the common ones alongside their atomic_t counterparts in Documentation/memory-barriers.txt. Signed-off-by: Paul E. McKenney Cc: David Howells --- Documentation/memory-barriers.txt | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt index 1d067235b0bc..2d22da095a60 100644 --- a/Documentation/memory-barriers.txt +++ b/Documentation/memory-barriers.txt @@ -1728,21 +1728,23 @@ explicit lock operations, described later). These include: xchg(); cmpxchg(); - atomic_xchg(); - atomic_cmpxchg(); - atomic_inc_return(); - atomic_dec_return(); - atomic_add_return(); - atomic_sub_return(); - atomic_inc_and_test(); - atomic_dec_and_test(); - atomic_sub_and_test(); - atomic_add_negative(); - atomic_add_unless(); /* when succeeds (returns 1) */ + atomic_xchg(); atomic_long_xchg(); + atomic_cmpxchg(); atomic_long_cmpxchg(); + atomic_inc_return(); atomic_long_inc_return(); + atomic_dec_return(); atomic_long_dec_return(); + atomic_add_return(); atomic_long_add_return(); + atomic_sub_return(); atomic_long_sub_return(); + atomic_inc_and_test(); atomic_long_inc_and_test(); + atomic_dec_and_test(); atomic_long_dec_and_test(); + atomic_sub_and_test(); atomic_long_sub_and_test(); + atomic_add_negative(); atomic_long_add_negative(); test_and_set_bit(); test_and_clear_bit(); test_and_change_bit(); + /* when succeeds (returns 1) */ + atomic_add_unless(); atomic_long_add_unless(); + These are used for such things as implementing LOCK-class and UNLOCK-class operations and adjusting reference counters towards object destruction, and as such the implicit memory barrier effects are necessary. -- 1.8.1.5