Re: kern/41417 (WAPBL: hang on tstile)

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

The following reply was made to PR kern/41417; it has been noted by GNATS.

From: Manuel Bouyer <bouyer%antioche.eu.org@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: dholland%NetBSD.org@localhost, gnats-admin%NetBSD.org@localhost, 
netbsd-bugs%NetBSD.org@localhost
Subject: Re: kern/41417 (WAPBL: hang on tstile)
Date: Wed, 27 Jul 2011 18:24:00 +0200

 On Wed, Jul 27, 2011 at 04:00:12PM +0000, David Holland wrote:
 >  I saw when pounding on it that from time to time the whole thing would
 >  stop for a while, then (maybe after a timeout somewhere) would resume
 >  again.
 >  
 >  I'm pretty sure that isn't either anything I did or a locking issue;
 >  hangs from locking issues tend to be permanent.
 >  
 >   >  Select blocks, and returns after the timeout period, while there is data
 >   >  ready to be read. The next select call returns immediatly. Did something
 >   >  change in this area recently ?
 >  
 >  Possibly; I'm not sure.
 >  
 >  Another candidate is the weird raidframe throughput problems mrg was
 >  seeing and possibly also some of the NFS hangs I was seeing a few
 >  weeks ago(*); and maybe some other related phenomena that have been
 >  reported. It looks as if maybe there's a problem where under some
 >  circumstances callouts stop getting processed... I think there's
 >  discussion on tech-kern and it's probably best to look there.
 
 Actually, callouts are working fine it seems. It looks like it's select
 not being woken up  when there's data ready in the socket buffer
 instead.
 
 -- 
 Manuel Bouyer <bouyer%antioche.eu.org@localhost>
      NetBSD: 26 ans d'experience feront toujours la difference
 --