Re: apparently missing locking in if_bnx.c

[Beverly Schwartz <bschwart%bbn.com@localhost>]

On Mar 6, 2012, at 7:15 PM, Greg Troxel wrote:

> My understanding is that the above stress test with 3 pairs of wm
> (yesterday or today netbsd-6) also leads to hangs.  (wm doesn't use
> workqueues, so it must be something else.  But wm quad-port cards seem
> to have funky bridge chips that netbsd-5 at least doesn't handle.)
I paired a machine w/ wm interfaces with a machine w/ bnx interfaces.

If I run wget on the machine w/ the bnx interfaces (3x, one for each interface, 
pulling data from wm machine to bnx machine), it would take a long time to get 
bad (freeze/hang) behavior.

If I run wget on the machine w/ the wm interfaces (3x, one for each interface, 
pulling data from bnx machine to wm machine), I get a freeze pretty promptly.

I can get a freeze with or without lockdebug.  So I don't know if lockdebug 
affects the underlying problem.

I will say that with the bnx problem, if I ran without lockdebug, then I would 
get a panic in the m_freem in bnx_tx_intr.  If I ran *with* lockdebug, I would 
get a freeze up quite quickly with no indication of where or what the problem 
was.

Lockdebug, so far, has been entirely unhelpful, even detrimental.

I will be spending some more time with lockdebug tomorrow.

-Bev