From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 16 Jun 2000 12:08:06 -0300 (BRST) From: Rik van Riel Subject: Re: kswapd eating too much CPU on ac16/ac18 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: Mike Galbraith Cc: Alan Cox , Cesar Eduardo Barros , linux-kernel , linux-mm@kvack.org List-ID: On Fri, 16 Jun 2000, Mike Galbraith wrote: > On Wed, 14 Jun 2000, Alan Cox wrote: > > > Im interested to know if ac9/ac10 is the slow->fast change point > > ac5 is definately the breaking point. ac5 doesn't survive make > -j30.. starts swinging it's VM machette at everything in sight. > Reversing the VM changes to ac4 restores throughput to test1 > levels (11 minute build vs 21-26 minutes for everything > forward). > > Exact tested reversals below. FWIW, page aging doesn't seem to > be the problem. I disabled that in ac17 and saw zero > difference. (What may or not be a hint is that the /* Let > shrink_mmap handle this swapout. */ bit in vmscan.c does make a > consistent difference. Reverting that bit alone takes a minimum > of 4 minutes off build time) Interesting. Not delaying the swapout IO completely broke performance under the tests I did here... Delayed swapout vs. non-delayed swapouts was the difference between 300 swapouts/s vs. 700 swapouts/s (under a load with 400 swapins/s). OTOH, I can imagine it being better if you have a very small LRU cache, something like less than 1/2 MB. regards, Rik -- The Internet is not a network of computers. It is a network of people. That is its real strength. Wanna talk about the kernel? irc.openprojects.net / #kernelnewbies http://www.conectiva.com/ http://www.surriel.com/ -- 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.eu.org/Linux-MM/