From owner-freebsd-hackers Wed Jul 22 12:03:29 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id MAA00622 for freebsd-hackers-outgoing; Wed, 22 Jul 1998 12:03:29 -0700 (PDT) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from tim.xenologics.com (tim.xenologics.com [194.77.5.24]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id MAA00503 for ; Wed, 22 Jul 1998 12:02:54 -0700 (PDT) (envelope-from seggers@semyam.dinoco.de) Received: (from uucp@localhost) by tim.xenologics.com (8.8.5/8.8.8) with UUCP id VAA28940; Wed, 22 Jul 1998 21:00:24 +0200 (MET DST) Received: from semyam.dinoco.de (semyam.dinoco.de [127.0.0.1]) by semyam.dinoco.de (8.8.8/8.8.8) with ESMTP id SAA20605; Wed, 22 Jul 1998 18:51:22 +0200 (CEST) (envelope-from seggers@semyam.dinoco.de) Message-Id: <199807221651.SAA20605@semyam.dinoco.de> To: zhihuizhang Cc: freebsd-hackers@FreeBSD.ORG, seggers@semyam.dinoco.de Subject: Re: Questions on inactive page queue In-reply-to: Your message of "Tue, 21 Jul 1998 16:52:12 EDT." Date: Wed, 22 Jul 1998 18:51:22 +0200 From: Stefan Eggers Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > (2) I find that the VM fault routine vm_fault() can call tsleep() to > sleep! This contradict my knowledge that interrupt routine can never go to > sleep. How can this happen? When you get a normal interrupt there might be whatever process run- ning at that time and you would make it go to sleep then if sleeping in interrupts were OK. Now imagine the X server sleeping because of a printer port interrupt for example. And sometimes there even is no process running at all. W/o a process tsleep isn't able to do its work as far as I know. Someone please correct me if I'm wrong with this. In contrast to this a page fault for a process's address space is always associated with that process and that one you put to sleep. You will always pick the right process and are guaranteed to have one. Doing a sleep then is OK. Stefan. -- Stefan Eggers Lu4 yao2 zhi1 ma3 li4, Max-Slevogt-Str. 1 ri4 jiu3 jian4 ren2 xin1. 51109 Koeln Federal Republic of Germany To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message