From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Cree Subject: Re: [PATCH 01/10] alpha: Add missing RCU idle APIs on idle loop Date: Thu, 23 Aug 2012 21:32:18 +1200 Message-ID: <5035F8A2.1070702@orcon.net.nz> References: <1345652628-15060-1-git-send-email-fweisbec@gmail.com> <1345652628-15060-2-git-send-email-fweisbec@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1345652628-15060-2-git-send-email-fweisbec@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Frederic Weisbecker Cc: LKML , Richard Henderson , Ivan Kokshaysky , Matt Turner , alpha , "Paul E. McKenney" , "3.2.x.." On 23/08/12 04:23, Frederic Weisbecker wrote: > In the old times, the whole idle task was considered > as an RCU quiescent state. But as RCU became more and > more successful overtime, some RCU read side critical > section have been added even in the code of some > architectures idle tasks, for tracing for example. Fantastic! It fixes RCU CPU stalls that we were seeing on the SMP kernel when built for generic Alpha. A build of glibc and running its test suite reliably triggers RCU CPU stalls when running a kernel built for generic Alpha. I have just built glibc and ran its test suite twice with no RCU CPU stalls with this patch against a 3.5.2 kernel! Nice. Very nice. I see the stable queue is CCed but I note the patch does not apply cleanly to the 3.2.y kernel. It would be nice to have a backport of the patches for the 3.2 stable kernel. So feel free to add: Tested-by: Michael Cree Cheers Michael.