From owner-freebsd-hackers Mon Oct 27 14:22:57 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id OAA01195 for hackers-outgoing; Mon, 27 Oct 1997 14:22:57 -0800 (PST) (envelope-from owner-freebsd-hackers) Received: from server.local.sunyit.edu (A-T34.rh.sunyit.edu [150.156.210.241]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id OAA01158 for ; Mon, 27 Oct 1997 14:21:49 -0800 (PST) (envelope-from perlsta@cs.sunyit.edu) Received: from localhost (perlsta@localhost) by server.local.sunyit.edu (8.8.7/8.8.5) with SMTP id SAA00985; Mon, 27 Oct 1997 18:25:44 -0500 (EST) X-Authentication-Warning: server.local.sunyit.edu: perlsta owned process doing -bs Date: Mon, 27 Oct 1997 18:25:44 -0500 (EST) From: Alfred Perlstein X-Sender: perlsta@server.local.sunyit.edu To: Terry Lambert cc: hackers@FreeBSD.ORG Subject: Re: help with fstat? and improvement on FreeBSD? In-Reply-To: <199710271815.LAA23283@usr04.primenet.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk that doesn't seem to be too hard to implement and could signifigantly speed up a LOT of things, would anyone want to tackle this problem? maybe someone could point me to where this code is located... i would like to try, i'm sure though, that someone with a bit more experiance would find it very easy to implement. in my opinion, many many things would gain a lot more speed if this algorithm was implement. -Alfred > > Remember also that each process has its own virtual address space. > > They can't "collide" with each other in some way. Each process could > > mmap huge chunks and you'd never have to worry. > > Except if you linearly traverse the mapped file, and it's a big file. > Then it will force almost all other clean pages out of core via LRU. > > So you can thrash the paging algorithm this way. > > But you can also thrash it (albiet less quickly) using reads. > > There used to be a MAP_SEQUENTIAL flag to get it to discard buffers > after they had been accesed, instead of forcing more pages off the > LRU, but BSD doesn't support this. 8-(. > > > Terry Lambert > terry@lambert.org > --- > Any opinions in this posting are my own and not those of my present > or previous employers. >