[OpenAFS-devel] kernel panic running iozone under Mac OS X

[Edward Moy]

I'm running iozone (http://www.iozone.org/) to benchmark OpenAFS.   
Using "iozone -Rac" on a local disk finishes in under an hour.  But  
with OpenAFS, it ran for about 3 1/2 hour and then kernel paniced.  The  
panic.log looks like:

------------------------------
panic(cpu 0): zalloc
Latest stack backtrace for cpu 0:
       Backtrace:
          0x000856CC 0x00085AFC 0x000287A8 0x00042610 0x0002D588  
0x001DE940 0x001FEEE8 0x001FBD48
          0x16077694 0x16078998 0x16078D00 0x1608B650 0x1608D1D8  
0x0020E8CC 0x00092830 0x0042000A
       Kernel loadable modules in backtrace (with dependencies):
          org.openafs.filesystems.afs(1.2.8)@0x16020000
Proceeding back via exception chain:
    Exception state (sv=0x129C0000)
       PC=0x9000514C; MSR=0x0000D030; DAR=0x000250B0; DSISR=0x40000000;  
LR=0x000058EC; R1=0xBFFFC800; XCP=0x00000030 (0xC00 - System call)

Kernel version:
Darwin Kernel Version 6.3:
Sat Dec 14 03:11:25 PST 2002; root:xnu/xnu-344.23.obj~4/RELEASE_PPC
------------------------------

I ran it a second time, with the same results.

I'm using OpenAFS 1.2.8 with the latest osi_vnodeops.c to fix the  
reading beyond EOF problem, plus various patches on the server side.

Stepping through the backtrace, it seems to be in rx_knet.c, where  
osi_NetReceive() calls soreceive(), but that's about as far as I know  
about.

The output from iozone:

                                                             random   
random    bkwd  record  stride
               KB  reclen   write rewrite    read    reread    read    
write    read rewrite    read   fwrite frewrite   fread  freread
...
            65536    4096    7469     111      124      119    1963    
40811

seems to stop between the "random write" and "bkwd read" test, assuming  
it is flushing its output appropriately.

Performance, as noted by others, leaves much to be desired, but it  
shouldn't cause a panic.

Any ideas?
------------------------------------------------------------------------ 
--
Edward Moy
Apple Computer, Inc.
emoy@apple.com

(This message is from me as a reader of this list, and not a statement
from Apple.)