From mboxrd@z Thu Jan 1 00:00:00 1970 From: William Allen Simpson Subject: [PATCH] Documentation: rw_lock lessons learned Date: Tue, 10 Nov 2009 13:23:49 -0500 Message-ID: <4AF9AFB5.7080809@gmail.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------020008060903090007010701" Cc: Eric Dumazet , "Paul E. McKenney" To: Linux Kernel Developers , Linux Kernel Network Developers Return-path: Received: from mail-bw0-f227.google.com ([209.85.218.227]:40616 "EHLO mail-bw0-f227.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757511AbZKJSXu (ORCPT ); Tue, 10 Nov 2009 13:23:50 -0500 Sender: netdev-owner@vger.kernel.org List-ID: This is a multi-part message in MIME format. --------------020008060903090007010701 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit In recent weeks, two different network projects erroneously strayed down the rw_lock path. Update the Documentation based upon comments in those threads. --- Documentation/spinlocks.txt | 14 ++++++++++++++ 1 files changed, 14 insertions(+), 0 deletions(-) --------------020008060903090007010701 Content-Type: text/plain; x-mac-type="54455854"; x-mac-creator="0"; name="spinlocks.txt.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="spinlocks.txt.patch" diff --git a/Documentation/spinlocks.txt b/Documentation/spinlocks.txt index 619699d..c112052 100644 --- a/Documentation/spinlocks.txt +++ b/Documentation/spinlocks.txt @@ -233,4 +233,18 @@ indeed), while write-locks need to protect themselves against interrupts. Linus +---- + +The implications of spin_locks on memory are further described in: + + Documentation/memory-barriers.txt + (5) LOCK operations. + (6) UNLOCK operations. + +---- + +We are working hard to remove reader-writer spinlocks (rw_lock) from the +network stack, so please don't add a new one. Instead, see: + + Documentation/RCU/rcu.txt -- 1.6.3.3 --------------020008060903090007010701--