Re: kern/49305: deadlocks on sparc64 SMP

[Michael <macallan%netbsd.org@localhost>]

The following reply was made to PR kern/49305; it has been noted by GNATS.

From: Michael <macallan%netbsd.org@localhost>
To: Martin Husemann <martin%duskware.de@localhost>
Cc: Mindaugas Rasiukevicius <rmind%netbsd.org@localhost>, gnats-bugs%NetBSD.org@localhost,
 kern-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
Subject: Re: kern/49305: deadlocks on sparc64 SMP
Date: Sun, 9 Nov 2014 11:33:43 -0500

 Hello,
 
 On Sun, 9 Nov 2014 17:16:01 +0100
 Martin Husemann <martin%duskware.de@localhost> wrote:
 
 > On Sun, Nov 09, 2014 at 03:13:21PM +0000, Mindaugas Rasiukevicius wrote:
 > > Unlikely to be pcq(9).  Most likely this is related to software interrupts
 > > or IPIs on sparc64, see softint_schedule_cpu(9).  Unfortunately, I do not
 > > have time to look into sparc64 MD code right now.
 > 
 > Possible, but why does the "always use the other cpu for softint processing"
 > version not trigger it?
 
 Might be a fluke but to me it looks like the problem happens
 ( sometimes ) when we schedule two software interrupts on different
 CPUs in quick succession.
 
 have fun
 Michael