From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 28 Jun 1999 22:13:15 -0400 (EDT) From: Chuck Lever Subject: Re: filecache/swapcache questions [RFC] [RFT] [PATCH] kanoj-mm12-2.3.8 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: "Stephen C. Tweedie" , Kanoj Sarcar , torvalds@transmeta.com, linux-mm@kvack.org List-ID: On Tue, 29 Jun 1999, Andrea Arcangeli wrote: > On Mon, 28 Jun 1999, Stephen C. Tweedie wrote: > > >> if you need evidence that shrink_mmap() will keep a system running without > >> swapping, just run 2.3.8 :) :) > > > >2.3.8 shows up slower on several benchmarks because of its reluctance to > >swap. > > Here the point is if you are swapping over your ramdisk or over my HD :). > Over my HD (system+swap all in the same IDE disk) you must _avoid_ to swap > at all costs if you care about performances. i'm not so sure about that. swapping out, if efficiently done, is a series of asynchronous sequential writes. the only performance that will interfere with is heavily I/O-bound applications. even so, if it gets more pages out of an application's way, then shrink_mmap will be less destructive to your working set, which is a *good* thing, and your caches will perform better. at least, that's the way i've seen it with the workloads i've been playing with. so, i believe that swapping (paging) is my friend, up to a point. - Chuck Lever -- corporate: personal: or The Linux Scalability project: http://www.citi.umich.edu/projects/linux-scalability/ -- 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/