From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <47FBB497.4050603@cs.helsinki.fi> Date: Tue, 08 Apr 2008 21:08:23 +0300 From: Pekka Enberg MIME-Version: 1.0 Subject: Re: [patch] slub: change the formula which calculates min_objects based on number of processors References: <20080404225019.369359572@sgi.com> <20080404225105.959019108@sgi.com> <1207548437.12878.48.camel@ymzhang> <47FA346C.4020802@cs.helsinki.fi> <1207635477.12878.74.camel@ymzhang> <84144f020804072337s541646d8s999be14b4c17375e@mail.gmail.com> <1207646286.12878.150.camel@ymzhang> In-Reply-To: <1207646286.12878.150.camel@ymzhang> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: "Zhang, Yanmin" Cc: Christoph Lameter , Matt Mackall , Nick Piggin , linux-mm@kvack.org List-ID: Zhang, Yanmin wrote: > Current formula to calculate min_objects based on number of processors is > '4 * fls(nr_cpu_ids)', which is not the best optimization on 16-core tigerton. > If I add 4 to its result, hackbench result is better. > > On 16-core tigerton, by run > ./hackbench 100 process 2000 > results are: > 1) 2.6.25-rc6slab: 23.5seconds > 2) 2.6.25-rc7SLUB+slub_min_objects=20: 31seconds > 3) 2.6.25-rc7SLUB+slub_min_objects=24: 23.5seconds > > So adding 4 to the output of '4 * fls(nr_cpu_ids)' could get the similar result > like CONFIG_SLAB=y. Applied, thanks! -- 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