Re: wapbl causing hangs

[Greg Oster <oster%cs.usask.ca@localhost>]

Mark Davies writes:
> On a dell poweredge 1950 running current from a few days ago I have a 
> couple of filesystems that are identical except one is mounted with "-o 
> log" and the other with "-o softdep".  If I try to copy approx 34GB from 
> another machine to the softdep filesystem (via "tar | ssh tar" or rsync) 
> it works fine, but if I try to do the same to the wapbl filesystem the 
> whole machine hangs after a couple of GB.  Unfortunately the machine just 
> hangs solidly without any indication of what happened.  Any suggestions on 
> what I can do to try and get more info on whats going wrong?

That Dell uses the mfi driver like the Dell 2950, yes?  
If so, see PR#39297 :(

(Basically WAPBL initiates a flush on the disk/raid cache, and, well, 
let's just say calling ltsleep() from mfi_intr() context is Bad..)

Later...

Greg Oster