From owner-freebsd-current Tue Aug 25 11:11:03 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id LAA06723 for freebsd-current-outgoing; Tue, 25 Aug 1998 11:11:03 -0700 (PDT) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from khavrinen.lcs.mit.edu (khavrinen.lcs.mit.edu [18.24.4.193]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id LAA06707 for ; Tue, 25 Aug 1998 11:10:53 -0700 (PDT) (envelope-from wollman@khavrinen.lcs.mit.edu) Received: (from wollman@localhost) by khavrinen.lcs.mit.edu (8.9.1/8.9.1) id OAA02595; Tue, 25 Aug 1998 14:10:02 -0400 (EDT) (envelope-from wollman) Date: Tue, 25 Aug 1998 14:10:02 -0400 (EDT) From: Garrett Wollman Message-Id: <199808251810.OAA02595@khavrinen.lcs.mit.edu> To: Doug Rabson Cc: Garrett Wollman , "John S. Dyson" , current@FreeBSD.ORG Subject: Re: Serious bug in vm_page.h in current In-Reply-To: References: <199808251441.KAA02038@khavrinen.lcs.mit.edu> Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG < said: >> >> PAGE_BWAKEUP would decr busy, and wakeup if PG_WANTED >> >> and busy == 0. >> >> >> >> PAGE_WAKEUP would clear PG_BUSY, and wakeup if PG_WANTED. >> >> >> >> Each of the above would ignore the other condition. There will >> >> be extra wakeups, but those won't significantly affect performance. > I think that John's patch as posted will not work at all due to a > misunderstanding. It will probably just cause hangs since vm_page::busy > will be decremented but never incremented. Not John's patch, John's description of the correct operation (quoted). -GAWollman -- Garrett A. Wollman | O Siem / We are all family / O Siem / We're all the same wollman@lcs.mit.edu | O Siem / The fires of freedom Opinions not those of| Dance in the burning flame MIT, LCS, CRS, or NSA| - Susan Aglukark and Chad Irschick To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message