Re: SMP hard lock with libpthread (thread X holds Y but isn't blocked on a lock)

From: Kris Kennaway <kris_at_obsecurity.org>
Date: Tue, 17 May 2005 15:41:42 -0700
On Tue, May 17, 2005 at 08:26:11AM -0700, othermark wrote:
> Kris Kennaway wrote:
> 
> > On Mon, May 16, 2005 at 08:33:14AM -0700, othermark wrote:
> >> I have an application that uses shared memory/threads and is linked with
> >> libpthread, running on May 10 -current.  Every time I run it, after a few
> >> minutes *poof* hard lock on a SMP box.  All debug options are enabled in
> >> the kernel, but it won't break to debugger.  Here's what appears on the
> >> console, and addr2line output follows:
> > 
> > Try the NMI debugger patches, which might be sufficient to get it into
> > DDB.
> > 
> > Kris
> 
> Jonathan's report on this issue, does have the stack trace, but seems to
> be triggered by nfs.
> 
> http://article.gmane.org/gmane.os.freebsd.current/69268

The 'turnstile' panic may be secondary, and the real panic was in some
other thread.  That's why you'd need to get into DDB.

> However, simply recompiling my application with libthr instead of libpthread
> completely avoids the panic.

Obviously not a real solution..

Kris

Received on Tue May 17 2005 - 20:41:48 UTC

This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:38:34 UTC