10gR1 SLES-9 Possible parallelism issue

Suse-Oracle gurus,


During a 64-bit conversion I completed on a new quad socket dual core DL 580 running SLES-9 SP3 and 10.1.0.5 RAC over Polyserve CFS this weekend, I observed
that only 4 CPUs were doing anything (other than being idle) during the CPU
intensive recompile portion.  I have done probably over a hundred database
upgrade on multiprocessor machines, and generally find that recompiling
invalidated objects works best (completes in the shortest time) when using a
parallelism of 4 times the number of CPU cores.  Since we have 8 cores on
the 580s, I used a parallelism of 32.  I could not complete the conversion
in RAC mode, so I could only use one machine.



@utlrcmp.sql

exec utl_recomp.recomp_parallel(32);



Usually when I kick off a recompile in this manner, I see 32 job workers kicked
off at the database level, and when watching top, I can see 32 processes (on
linux, make the xterm window longer) running at high CPU utilization.


Are system setting or kernel parameter (sysctl.conf) that
might be only allowing 4 processes to run on CPU simultaneously?  I am not
concerned as much about the recompile time as that when we turn on the
64-bit database in production, only 4 CPU cores will do any work, and the other
4 will sit around idle.  The sysadmins indicate they built a kernel with “make
–j 32” and saw at least 12 instances of gcc running
concurrently.



I am hoping this is not a Xeon limitation.  Last time I did a 64-bit
conversion on an Opteron based HP DL 585 running SLES-9, I saw fantastic
performance on the recompile, and 32 oracle processes were seen via top as
described above.

Thanks,
-Michael Taylor



       
____________________________________________________________________________________
Take the Internet to Go: Yahoo!Go puts the Internet in your pocket: mail, news, photos & more. 
http://mobile.yahoo.com/go?refer=1GNXIC