From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: kswapd eating too much CPU on ac16/ac18 References: From: Goswin Brederlow Date: 19 Jun 2000 23:22:58 +0200 In-Reply-To: Rik van Riel's message of "Sat, 17 Jun 2000 12:33:52 -0300 (BRST)" Message-ID: <877lbl8ix9.fsf@mose.informatik.uni-tuebingen.de> Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel Cc: Cesar Eduardo Barros , Mike Galbraith , Alan Cox , linux-kernel , linux-mm@kvack.org List-ID: >>>>> " " == Rik van Riel writes: > I think the phenomenon you're seeing is not at all related to > deferred/non-deferred swapout. That doesn't have anything to do > with kswapd CPU usage. > The changed feedback loop in do_try_to_free_pages, however may > have something to do with this. It works well on machines with > more than 1 memory zone, but I can envision it breaking on > machines with just one zone... > I'm thinking of a way to fix this cleanly, I'll keep you > posted. I have two boxes with 2.4.0-test1 kernels: First one a Celeron 466 with 128 Mb ram: BIOS-provided physical RAM map: e820: 000000000009f000 @ 0000000000000000 (usable) e820: 0000000007f00000 @ 0000000000100000 (usable) On node 0 totalpages: 32768 zone(0): 4096 pages. zone(1): 28672 pages. zone(2): 0 pages. Second one a P120 with 16 MB ram (probably in one zone, but its not in reach at the moment). On the Celeron 2.4.0-test1 runs fine (responsiveness is a bit low, but kswapd useage is fine). On the P120 kswapd needs 95-99% cpu time. and the system is realy realy slow. I teste plain 2.4.0-test1 to 2.2.4-test1-ac19 with various steps inbetween. The disk behaviour (how often the ide led blinks) differs and the amount swap used is different, but the kswap allways uses all cpu time. This could realy be a "number of zones" problem, so pleas thing about it. MfG Goswin PS: I will add a zone mapping for the P120 when I get to it next time. -- 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/