On Sun, 19 May 1996 02:44:35 +0900 
 Noriyuki Soda <soda@sra.co.jp> wrote:

 > Probably this problem should be fixed in MI SCSI level, not ahc driver 
 > level, as discussed in current-users. I think Charles or Jason is 
 > working to fix this. Not ?

Well, Charles and I have both thought about it, but I'm not personally 
actively working on it ... I have some other things much higher on my 
TODO list...I don't know about charles...

 > If not, or if correct fix takes time, we can avoid this specific problem 
 > by allocating memory in ahcattach(). (Though this is not correct fix, 
 > only workaround)

Sometime during the release cycle for 1.2, we'll have to make a decision 
whether or not putting in the work-around you suggest is appropriate as 
a stop-gap, depending on whether or not the underlying problem of SCSI 
resource allocation has been addressed.

 > > ahc0: Can't malloc SCB
 > > sd2: not queued, error 5
 > > swap_pager_clean: clean of page 16b8000 failed
 > 
 > This situation is quite dangerous.

Yah ... your system could really lose...Basically, your system isn't able 
to deal with swap housekeeping because access to swap partitions is 
losing to resource shortage ... the problem probably compounds itself ... 
memory shortage, wants to page some things out so it can free up some 
core, SCSI subsystem requires malloc(), but can't block, so it fails, so 
it can't page stuff out, repeat ad nauseum.

----save the ancient forests - http://www.bayarea.net/~thorpej/forest/----
Jason R. Thorpe                                       thorpej@nas.nasa.gov
NASA Ames Research Center                               Home: 408.866.1912
NAS: M/S 258-6                                          Work: 415.604.0935
Moffett Field, CA 94035                                Pager: 415.428.6939