From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by e3.ny.us.ibm.com (8.12.11/8.12.11) with ESMTP id k0VIm4iT028570 for ; Tue, 31 Jan 2006 13:48:04 -0500 Received: from d01av04.pok.ibm.com (d01av04.pok.ibm.com [9.56.224.64]) by d01relay04.pok.ibm.com (8.12.10/NCO/VERS6.8) with ESMTP id k0VIm4YB199158 for ; Tue, 31 Jan 2006 13:48:04 -0500 Received: from d01av04.pok.ibm.com (loopback [127.0.0.1]) by d01av04.pok.ibm.com (8.12.11/8.13.3) with ESMTP id k0VIm3uA025454 for ; Tue, 31 Jan 2006 13:48:03 -0500 Message-ID: <43DFB0D7.3070805@us.ibm.com> Date: Tue, 31 Jan 2006 12:47:51 -0600 From: Brian Twichell MIME-Version: 1.0 Subject: Re: [PATCH/RFC] Shared page tables References: <43DAA3C9.9070105@us.ibm.com> <200601301246.27455.raybry@mpdtxmail.amd.com> In-Reply-To: <200601301246.27455.raybry@mpdtxmail.amd.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Ray Bryant Cc: Hugh Dickins , Dave McCracken , Andrew Morton , Linux Kernel , Linux Memory Management List-ID: Ray Bryant wrote: >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? > > I believe it does. Dave, can you confirm ? >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? > > Yes. My original post with performance data described a 3% improvement in the ppc64/hugepage case. This is a transaction throughput statement. >(I'm assuming your 25-50% improvement measurements, as mentioned in a previous >note, was for small pages.) > > > That's correct. -- 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