From owner-freebsd-hackers Wed Jul 22 17:27:50 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id RAA29521 for freebsd-hackers-outgoing; Wed, 22 Jul 1998 17:27:50 -0700 (PDT) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from implode.root.com (implode.root.com [198.145.90.17]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id RAA29513 for ; Wed, 22 Jul 1998 17:27:45 -0700 (PDT) (envelope-from root@implode.root.com) Received: from implode.root.com (localhost [127.0.0.1]) by implode.root.com (8.8.5/8.8.5) with ESMTP id RAA07941; Wed, 22 Jul 1998 17:26:19 -0700 (PDT) Message-Id: <199807230026.RAA07941@implode.root.com> To: zhihuizhang cc: Julian Elischer , hackers Subject: Re: Questions on inactive page queue In-reply-to: Your message of "Wed, 22 Jul 1998 12:37:02 EDT." From: David Greenman Reply-To: dg@root.com Date: Wed, 22 Jul 1998 17:26:19 -0700 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG >> > (1) Why we set a target for the inactive page queue? Who can manipulate >> > the pages on the inactive page queue? How to guarantee that a page won't >> > move from the inactive queue while paging out? >> > > >David Greenman answered my second question and part of the first one. I >guess that one of the hardest part of VM is to understand how pages get >moved around different queues. In my case, I want to know who could >possibly access the inactive queue at the same time the pageout is going >on. Accessing the queue and doing something to a page that is on it are different things. When the system wants to page out a page, the page is made read-only for all mappings of it and it is then set as busy so that 1) the page-reclaim part of the kernel leaves it alone on subsequant scans, and 2) so that if a page fault occurs for it, the fault will be suspended until the system is done paging it out. -DG David Greenman Co-founder/Principal Architect, The FreeBSD Project To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message