From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 4 Aug 1999 13:50:28 +0200 (CEST) From: Ingo Molnar Subject: Re: [patch] minimal page-LRU In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Andrea Arcangeli Cc: Linus Torvalds , MOLNAR Ingo , "David S. Miller" , linux-kernel@vger.rutgers.edu, linux-mm@kvack.org List-ID: On Wed, 4 Aug 1999, Andrea Arcangeli wrote: > I did only a little not interesting benchmark. I compiled the kernel with > 2.3.12 and 2.3.12-LRU and these are the numbers: > > 2.3.12: > real 3m0.974s > user 3m22.400s > sys 0m16.350s > > 2.3.12-lru: > real 2m58.483s > user 3m23.350s > sys 0m15.920s > > NOTE: I have 128mbyte of ram so the kernel almost fit in cache during the > compile and there isn't high I/O activity so I didn't ever expected such > two seconds improvement... even two seconds can be statistical noise (eg. look at the user-time numbers, those increased by one second.). But it's not so hard to test high-intensity VM with kernel compiles. This method is from Davem: compile the kernel with 'make -jN', where N = 1,2,3... increasingly. [also put 'make -jN' into the top Makefile.] Sometimes at N=6 or so you'll fall out of core 128M RAM. This is both a good stability and a good performance test. You can even automate it. This way you'll see both the effect on 'normal' (cached) and 'high load' (swapping) situations. Such a list of numbers is a much more reliable measurement of performance than just one arbitrary number. -- mingo -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://humbolt.geo.uu.nl/Linux-MM/