From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx150.postini.com [74.125.245.150]) by kanga.kvack.org (Postfix) with SMTP id D8A5F6B005D for ; Wed, 11 Jul 2012 16:48:57 -0400 (EDT) Received: from /spool/local by e35.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 11 Jul 2012 14:48:57 -0600 Received: from d03relay01.boulder.ibm.com (d03relay01.boulder.ibm.com [9.17.195.226]) by d03dlp01.boulder.ibm.com (Postfix) with ESMTP id 76D6CC40004 for ; Wed, 11 Jul 2012 20:48:52 +0000 (WET) Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by d03relay01.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q6BKmXZO279048 for ; Wed, 11 Jul 2012 14:48:33 -0600 Received: from d03av01.boulder.ibm.com (loopback [127.0.0.1]) by d03av01.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q6BKmWNa022582 for ; Wed, 11 Jul 2012 14:48:32 -0600 Message-ID: <4FFDE69C.8080205@linux.vnet.ibm.com> Date: Wed, 11 Jul 2012 15:48:28 -0500 From: Seth Jennings MIME-Version: 1.0 Subject: Re: [PATCH 0/4] zsmalloc improvements References: <1341263752-10210-1-git-send-email-sjenning@linux.vnet.ibm.com> <20120704204325.GB2924@localhost.localdomain> <4FF6FF1F.5090701@linux.vnet.ibm.com> <4FFAE37F.70403@linux.vnet.ibm.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: konrad@darnok.org Cc: Greg Kroah-Hartman , Andrew Morton , Dan Magenheimer , Konrad Rzeszutek Wilk , Nitin Gupta , Minchan Kim , Robert Jennings , linux-mm@kvack.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org On 07/11/2012 02:42 PM, Konrad Rzeszutek Wilk wrote: >>>> Which architecture was this under? It sounds x86-ish? Is this on >>>> Westmere and more modern machines? What about Core2 architecture? >>>> >>>> Oh how did it work on AMD Phenom boxes? >>> >>> I don't have a Phenom box but I have an Athlon X2 I can try out. >>> I'll get this information next Monday. >> >> Actually, I'm running some production stuff on that box, so >> I rather not put testing stuff on it. Is there any >> particular reason that you wanted this information? Do you >> have a reason to believe that mapping will be faster than >> copy for AMD procs? > > Sorry for the late response. Working on some ugly bug that is taking > more time than anticipated. > My thoughts were that these findings are based on the hardware memory > prefetcher. The Intel > machines - especially starting with Nehelem have some pretty > impressive prefetcher where > even doing in a linked list 'prefetch' on the next node is not beneficial. > > Perhaps the way to leverage this is to use different modes depending > on the bulk of data? > When there is a huge amount use the old method, but for small use copy > (as it would > in theory stay in the cache longer). Not sure what you mean by "bulk" or "huge amount" but the maximum size of mapped object is PAGE_SIZE and the typical size more around PAGE_SIZE/2. So that is what I'm considering. Do you think it makes a difference with copies that small? Thanks, Seth -- 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