The following reply was made to PR kern/37181; it has been noted by GNATS.

From: Andrew Doran <ad@netbsd.org>
To: gnats-bugs@NetBSD.org
Cc: kern-bug-people@netbsd.org, gnats-admin@netbsd.org,
	netbsd-bugs@netbsd.org, pooka@iki.fi
Subject: Re: kern/37181: kevent calls ltsleep() at splsched()
Date: Tue, 23 Oct 2007 13:56:28 +0100

 On Tue, Oct 23, 2007 at 08:05:17AM +0000, Martin Husemann wrote:
 
 >  Side note: I'd suggest we define a KASSERTMAXIPL() macro (arch dependend,
 >  or empty if not easy/not yet done) and sprinkle things like
 >  
 >      KASSERTMAXIPL(IPL_SCHED);
 >  
 >  (or in this case: KASSERTMAXIPL(IPL_SCHED+1), I guess)
 >  
 >  at a few strategic places.
 
 I think it is better (for the generic case) to convert to use locks or to
 make the code mulithreaded using other mechanisms. Then other assertions
 become available to you, for example KASSERT(mutex_owned(&foo_lock)).
 
 Simplyfing the SPL system will help greatly because it is poorly understood
 and relies on a pack of fragile assumptions. Random example: printf() may be
 called from network level interrupts, but IPL_TTY is not guaranteed to block
 network interrupts. We have a lot of code that works purely out of luck but
 lot of that has been fixed over the past year.
 
 http://mail-index.netbsd.org/tech-kern/2007/05/05/0005.html
 
 Andrew