From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with SMTP id BB19B6B01B2 for ; Mon, 28 Jun 2010 04:45:10 -0400 (EDT) Date: Mon, 28 Jun 2010 18:45:04 +1000 From: Nick Piggin Subject: Re: [patch] mm: vmap area cache Message-ID: <20100628084504.GC28364@laptop> References: <20100531080757.GE9453@laptop> <20100602144905.aa613dec.akpm@linux-foundation.org> <20100603135533.GO6822@laptop> <1277470817.3158.386.camel@localhost.localdomain> <20100626083122.GE29809@laptop> <1277714262.2461.2.camel@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1277714262.2461.2.camel@localhost> Sender: owner-linux-mm@kvack.org To: Steven Whitehouse Cc: Andrew Morton , Minchan Kim , linux-mm@kvack.org List-ID: On Mon, Jun 28, 2010 at 09:37:42AM +0100, Steven Whitehouse wrote: > Hi, > > On Sat, 2010-06-26 at 18:31 +1000, Nick Piggin wrote: > > On Fri, Jun 25, 2010 at 02:00:17PM +0100, Steven Whitehouse wrote: > > > Hi, > > > > > > Barry Marson has now tested your patch and it seems to work just fine. > > > Sorry for the delay, > > > > > > Steve. > > > > Hi Steve, > > > > Thanks for that, do you mean that it has solved thee regression? > > > > Thanks, > > Nick > > > > Yes, thats what I have heard from Barry. He said that it was pretty > close to the expected performance but did not give any figures. The fact > that his test actually completes shows that most of the problem has been > solved, Thanks, so I think it's good to go. It is interesting that it is just "close" to expected performance. The lazy vunmap patch is preventing a global IPI and TLB flush on all CPUs for every vfree() (amortizing it down to basically nothing if you are doing just small vmaps). Unless you are testing on a UP machine, I would have expected improved performance if you are doing a lot of vmalloc/vfree activity. It could be that the search is still taking some time, and is outweighing the gains. We have a few options for being cleverer, so if you're ever interested to get more detailed results and find a bit more performance here, let me know. And thanks for all the reporting and testing so far. -- 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