From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264777AbUEYTxq (ORCPT ); Tue, 25 May 2004 15:53:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265087AbUEYTxp (ORCPT ); Tue, 25 May 2004 15:53:45 -0400 Received: from mx1.elte.hu ([157.181.1.137]:19910 "EHLO mx1.elte.hu") by vger.kernel.org with ESMTP id S265092AbUEYTx0 (ORCPT ); Tue, 25 May 2004 15:53:26 -0400 Date: Tue, 25 May 2004 21:54:37 +0200 From: Ingo Molnar To: Manfred Spraul Cc: linux-kernel@vger.kernel.org Subject: Re: 4g/4g for 2.6.6 Message-ID: <20040525195437.GA10784@elte.hu> References: <40B3A35D.4020702@colorfullife.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <40B3A35D.4020702@colorfullife.com> User-Agent: Mutt/1.4.1i X-ELTE-SpamVersion: MailScanner 4.26.8-itk2 (ELTE 1.1) SpamAssassin 2.63 ClamAV 0.65 X-ELTE-VirusStatus: clean X-ELTE-SpamCheck: no X-ELTE-SpamCheck-Details: score=-4.9, required 5.9, autolearn=not spam, BAYES_00 -4.90 X-ELTE-SpamLevel: X-ELTE-SpamScore: -4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Manfred Spraul wrote: > >also, the 4:4 overhead is really a hardware problem - and there are > >x86-compatible CPUs (amd64) where the TLB flush problem has already been > >solved: on amd64 the 4:4 feature has no noticeable overhead. > > > Do you have an idea why amd64 is better for 4g4g? Which benchmark did > you use for testing? i used an althlon64 CPU. amd64 is better because it has a hardware feature that 'watches' for memory updates to cached TLBs, and it tags the TLBs by cr3. So it can avoid having to flush those TLBs that didnt actually change. So an amd64 CPU has in excess of 1000+ TLBs ... Ingo