From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mel (3-1-37.ore.fiber.net [209.90.103.38]) by mail.fiber.net (8.11.6/8.11.3) with ESMTP id g2FGrXj12731 for ; Fri, 15 Mar 2002 09:53:33 -0700 (MST) From: "Al T" Date: Fri, 15 Mar 2002 09:53:54 -0700 MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Subject: Set file cache size (2.4.18) Reply-to: at@fiber.net Message-ID: <3C91C4B2.8458.19B077CE@localhost> Sender: owner-linux-mm@kvack.org Return-Path: To: linux-mm@kvack.org List-ID: I am currently experimenting Linux on an old laptop I got cheap. It has a max. of 24 MB of ram and an ISA IDE controller. It is an old machine and runs quite well. I built my own Linux system to maximize its power. But, when I load large programs (KDE 2, for example), the system slows down to a crawl. This is what I've been able to figure out: - KDE 2 is a memory hog. In order to compensate for that, a lot of swap must be used. But, with a 3 MB/sec transfer speed, it's just not very fast. - According to TOP, the CPU is not in heavy use. It is usually 30% idle during the process, meaning the bottleneck is I/O. - At the end of the process, the swap usage is ~18,00k, with ~10,000k in buffer/cache. - X is not a problem, since it can be loaded without using swap. Based on this, I realized memory has been flipped around: what should be in disk (files) is now in memory (cache), and what should be in memory is now in disk (swap). I remember in Windows 95 it was possible to set the minimum and maximum values for the file cache. Tweaking these values increased performance on low memory systems, since it would ensure large amounts of memory were not used to cache the disk and memory pages would not be thrown out to disk. I've looked through /proc and on the internet for a way to change the maximum cache size. It seems like it was available on early 2.4 kernels, but it's not in the 2.4.18 kernel. How do I restrict the size of the cache and buffer? @ -- 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/