[issue1849] panic: dsched: malloc limit exceeded

[Matthew Dillon]

:> thread_ctx:	16998
:> thread_io:	118986
:> disk_ctx:	7
:> ---------------------------------------------
:The number of procs+threads should match the number of thread_ctx. That
:clearly isn't the case, which indicates that there are some stale
:references on the thread_ctx. I don't have much time to look into it
:this week, but I'll take a look at it next week.
:
:Cheers,
:Alex

    I'll mess with it a bit.  It's pretty clear that the extra thread_ctx's
    are getting stuck due to thread_io references which are not being torn
    down.  Now the question is how and where.

    It looks like there are a few places where subsystems still generate
    their own pbufs.  CCD, the original ata driver (not nata), and
    in fact devfs's device-special I/O is too.

    Are you using CCD or VN by any chance?  If not then there must be
    some interaction with devfs.

    I will commit some fixes in a bit so you can test as well, since
    you are able to reproduce it easily.

					-Matt
					Matthew Dillon 
					<dillon at backplane.com>