From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: Re: RCU red-black tree (was: Re: [PATCH 4/6] kvm tools: Add rwlock wrapper) Date: Tue, 31 May 2011 16:20:06 +0300 Message-ID: <1306848006.25406.11.camel@lappy> References: <1306491547.3217.9.camel@lappy> <20110527131400.GC29744@Krystal> <20110529170104.GA17189@Krystal> <1306691292.14564.12.camel@lappy> <20110530025414.GA25865@Krystal> <1306735631.14564.34.camel@lappy> <20110530173844.GA13361@Krystal> <1306777969.15912.3.camel@lappy> <20110530185757.GA13903@Krystal> <1306847114.25406.9.camel@lappy> <20110531130923.GA13888@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Mathieu Desnoyers , Pekka Enberg , Avi Kivity , john@jfloren.net, kvm@vger.kernel.org, asias.hejun@gmail.com, gorcunov@gmail.com, prasadjoshi124@gmail.com, "Paul E. McKenney" , Phil Howard , rp@svcs.cs.pdx.edu To: Ingo Molnar Return-path: Received: from mail-wy0-f174.google.com ([74.125.82.174]:33168 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754928Ab1EaNUj (ORCPT ); Tue, 31 May 2011 09:20:39 -0400 Received: by wya21 with SMTP id 21so3292588wya.19 for ; Tue, 31 May 2011 06:20:37 -0700 (PDT) In-Reply-To: <20110531130923.GA13888@elte.hu> Sender: kvm-owner@vger.kernel.org List-ID: On Tue, 2011-05-31 at 15:09 +0200, Ingo Molnar wrote: > * Sasha Levin wrote: > > > I've started working on converting our MMIO code to use RCU rbtree. > > Well, why would we want to switch the MMIO code away from the brlock > right now? mmio tree reconfigurations are very, very rare. > > Won't something like the qcow cache be more suitable for that? That > has both frequent read and write activities. We don't have a qcow cache at the moment :) It was either the MMIO or the ioport tree. We don't have to pull them into our master tree either - it's mostly a proof of concept I'm doing on a separate tree. -- Sasha.