From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx179.postini.com [74.125.245.179]) by kanga.kvack.org (Postfix) with SMTP id 5158E6B0034 for ; Mon, 17 Jun 2013 19:20:21 -0400 (EDT) Message-ID: <51BF99B0.4040509@intel.com> Date: Tue, 18 Jun 2013 07:20:16 +0800 From: Alex Shi MIME-Version: 1.0 Subject: Re: Performance regression from switching lock to rw-sem for anon-vma tree References: <1371165333.27102.568.camel@schen9-DESK> <1371167015.1754.14.camel@buesod1.americas.hpqcorp.net> <51BD8A77.2080201@intel.com> <1371486122.1778.14.camel@buesod1.americas.hpqcorp.net> In-Reply-To: <1371486122.1778.14.camel@buesod1.americas.hpqcorp.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Davidlohr Bueso Cc: Tim Chen , Ingo Molnar , Rik van Riel , Peter Zijlstra , Andrea Arcangeli , Mel Gorman , Andi Kleen , Andrew Morton , Michel Lespinasse , "Wilcox, Matthew R" , Dave Hansen , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" On 06/18/2013 12:22 AM, Davidlohr Bueso wrote: > After a lot of benchmarking, I finally got the ideal results for aim7, > so far: this patch + optimistic spinning with preemption disabled. Just > like optimistic spinning, this patch by itself makes little to no > difference, yet combined is where we actually outperform 3.10-rc5. In > addition, I noticed extra throughput when disabling preemption in > try_optimistic_spin(). > > With i_mmap as a rwsem and these changes I could see performance > benefits for alltests (+14.5%), custom (+17%), disk (+11%), high_systime > (+5%), shared (+15%) and short (+4%), most of them after around 500 > users, for fewer users, it made little to no difference. A pretty good number. what's the cpu number in your machine? :) -- Thanks Alex -- 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