threads/136345: Recursive read rwlocks in thread A cause deadlock with write lock in thread B

[Rink Springer]

The following reply was made to PR threads/136345; it has been noted by GNATS.

From: Rink Springer <rink at FreeBSD.org>
To: FreeBSD-gnats-submit at FreeBSD.org
Cc:  
Subject: Re: threads/136345: Recursive read rwlocks in thread A cause
	deadlock with write lock in thread B
Date: Sun, 5 Jul 2009 17:37:40 +0200

 On Sun, Jul 05, 2009 at 03:20:02PM +0000, Attilio Rao wrote:
 >  I think that rdlock_count in libthr is not updated properly.
 >  Can you test the following patch:
 >  http://www.freebsd.org/~attilio/libthr.diff
 
 This seems to resolve the issue; it seems to solve the deadlock the
 attached test program has.
 
 I'll retry it with my real workload and see if this fixes the problem -
 will let you know.
 
 Thanks!
 
 -- 
 Rink P.W. Springer                                - http://rink.nu
 "Doom, gloom and despair. I like it!"
 - Tiresias