Date: Tue, 4 Aug 1998 11:05:18 -0400 (EDT) From: Garrett Wollman <wollman@khavrinen.lcs.mit.edu> To: current@FreeBSD.ORG Cc: dillon@backplane.com, hag@ai.mit.edu Subject: Bizarre deadlock Message-ID: <199808041505.LAA01850@khavrinen.lcs.mit.edu>
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My Diablo news box is falling over at regular, annoying intervals. I had initially thought it was some sort of priority-inversion deadlock, but now it looks even more serious.... After spending about 45 minutes tracing through the system with DDB, I found: 1) Most processes are blocked on the inode for the root directory. (Of course, this means that any time a process wakes up and tries to do some I/O, it will get blocked.) 2) I could follow the chain of inode locks down through NINE processes. The process holding the root directory should only have been using it to do a lookup. 3) The lock on the inode at the end of the chain was wanted by three processes, but was either totally free, or was being held shared (oops, no way to tell by whom). I didn't write down enough information, unfortunately, to identify precisely which inode this was. -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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