Date: Tue, 25 Aug 1998 14:10:02 -0400 (EDT) From: Garrett Wollman <wollman@khavrinen.lcs.mit.edu> To: Doug Rabson <dfr@nlsystems.com> Cc: Garrett Wollman <wollman@khavrinen.lcs.mit.edu>, "John S. Dyson" <dyson@iquest.net>, current@FreeBSD.ORG Subject: Re: Serious bug in vm_page.h in current Message-ID: <199808251810.OAA02595@khavrinen.lcs.mit.edu> In-Reply-To: <Pine.BSF.4.01.9808251907120.17263-100000@herring.nlsystems.com> References: <199808251441.KAA02038@khavrinen.lcs.mit.edu> <Pine.BSF.4.01.9808251907120.17263-100000@herring.nlsystems.com>
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<<On Tue, 25 Aug 1998 19:08:18 +0100 (BST), Doug Rabson <dfr@nlsystems.com> 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
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