From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: [PATCH 2/2][RT] powerpc - Make the irq reverse mapping radix tree lockless Date: Fri, 25 Jul 2008 15:13:39 +1000 Message-ID: <1216962819.11188.82.camel@pasglop> References: <20080724122352.3bc76bda@bull.net> <20080724125044.53b604cb@bull.net> <200807242111.35338.nickpiggin@yahoo.com.au> Reply-To: benh@kernel.crashing.org Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Sebastien Dugue , Linux-rt , linux-ppc , linux-kernel , Paul Mackerras , Michael Ellerman , Tim Chavez , Jean Pierre Dion , Gilles Carry To: Nick Piggin Return-path: Received: from gate.crashing.org ([63.228.1.57]:60679 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750753AbYGYFOo (ORCPT ); Fri, 25 Jul 2008 01:14:44 -0400 In-Reply-To: <200807242111.35338.nickpiggin@yahoo.com.au> Sender: linux-rt-users-owner@vger.kernel.org List-ID: > > Concurrency between readers and writers are handled by the intrinsic > > properties of the concurrent radix tree. Concurrency between the tree > > initialization which is done asynchronously with readers and writers access > > is handled via an atomic variable (revmap_trees_allocated) set when the > > tree has been initialized and checked before any reader or writer access > > just like we used to check for tree.gfp_mask != 0 before. > > Hmm, RCU radix tree is in mainline too for quite a while. I thought > Ben had already converted this code over ages ago... > > Nothing against the -rt patch, but mainline should probably be updated > to use RCU as well? No, I haven't updated that code yet, and yes, we should do it :-) Cheers, Ben.