Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964874AbWA3S5k (ORCPT ); Mon, 30 Jan 2006 13:57:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964873AbWA3S5k (ORCPT ); Mon, 30 Jan 2006 13:57:40 -0500 Received: from amdext4.amd.com ([163.181.251.6]:8358 "EHLO amdext4.amd.com") by vger.kernel.org with ESMTP id S964874AbWA3S5j (ORCPT ); Mon, 30 Jan 2006 13:57:39 -0500 X-Server-Uuid: 5FC0E2DF-CD44-48CD-883A-0ED95B391E89 From: "Ray Bryant" To: "Brian Twichell" Subject: Re: [PATCH/RFC] Shared page tables Date: Mon, 30 Jan 2006 12:46:24 -0600 User-Agent: KMail/1.8 cc: "Hugh Dickins" , "Dave McCracken" , "Andrew Morton" , "Linux Kernel" , "Linux Memory Management" References: <43DAA3C9.9070105@us.ibm.com> In-Reply-To: <43DAA3C9.9070105@us.ibm.com> MIME-Version: 1.0 Message-ID: <200601301246.27455.raybry@mpdtxmail.amd.com> X-OriginalArrivalTime: 30 Jan 2006 18:57:07.0826 (UTC) FILETIME=[F7D80D20:01C625CE] X-WSS-ID: 6FC0BE090BO1435296-01-01 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1605 Lines: 50 On Friday 27 January 2006 16:50, Brian Twichell wrote: > > Hi, > > We collected more granular performance data for the ppc64/hugepage case. > > CPI decreased by 3% when shared pagetables were used. Underlying this was > a 7% decrease in the overall TLB miss rate. The TLB miss rate for > hugepages decreased 39%. TLB miss rates are calculated per instruction > executed. > Interesting. Do you know if Dave's patch supports sharing of pte's for 2 MB pages on X86_64? Was there a corresponding improvement in overall transaction throughput for the hugetlb, shared pte case? That is, did the 3% improvement in CPI translate to a measurable improvement in the overall OLTP benchmark score? (I'm assuming your 25-50% improvement measurements, as mentioned in a previous note, was for small pages.) > We didn't collect a profile per se, as we would expect a CPI improvement > of this nature to be spread over a significant number of functions, > mostly in user-space. > > Cheers, > Brian > > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: email@kvack.org -- Ray Bryant AMD Performance Labs Austin, Tx 512-602-0038 (o) 512-507-7807 (c) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/