Subject: re: UVM failure :(
To: Michael L. Hitch <mhitch@lightning.oscs.montana.edu>
From: matthew green <mrg@eterna.com.au>
List: port-pmax
Date: 11/02/1998 18:58:17
   > i booted a UVM kernel (same very -current sources as the non-UVM kernel
   > i successfully booted only hours ago) on my /240 and it didn't like me:
   > 
   > root file system type: ffs
   > init: copying out path `/sbin/init' 11
   > uvm_anon_add: can not allocate 50999 anons
   > panic: uvm_anon_add
   > 
   > this would have been while swapctl was running ... 
   > 
   > i'll have more details when i look deeper at it.
   
     Have you found out anything more about this?

only in so far that it runs out of kernel memory.
   
     I just took a look at uvm_anon_add(), and it looks like it's trying
   to allocate 50999 pages (!).   As far as I can tell, this only comes
   from swap_on() in uvm_swap.c.  Ah, I wonder if that expression to
   calculate the number of pages might be messing up?  It looks like it's
   trying to convert the number of blocks to a 64 bit value, convert to
   the number of bytes, and then shift by PAGE_SHIFT to get the number of
   pages.  Any bets there's an error in that expression somewhere (either
   a code generation bug or something incorrect in the expression -
   presumably mips-specific)?  [Ugh - I'm too tired to try to figure out
   just what the assembly code is doing.]


not 50999 pages, but 50999 anons -- one for each physical page of
swap space i have... (~200M).  this is "normal" .. but appears to
be blowing out my kernel map :-(