Yes, the amount of idle and system time is *incredible*. Something must be wrong. More than 20 running processes are reported by 'top' most of the time, but at most 4 to 6 are on CPU at any given moment.What kind of workload are you running? What are these 20 running processes doing?
It is a full nightly build of OS/Net. Most of those running processes are compilers (cc, gcc) and dmake also comsumes a considerable amout of time. There is no intensive disk activity, no anonymous paging. The VM has 3 GB of memory, which seems to be sufficient for the build.
This happens on a 64-bit VirtualBox (3.2.4 r62467) guest running on a Linux host (4-core Core i7 (8 threads)). Setting a lower number of CPUs (such as 4) does not help. Uniprocessor guests seem to work normally (with IO APIC disabled). I've read about bugs affecting the IO APIC performance under VirtualBox, but all the reports say they are only relevant for 32-bit guests. This is a 64-bit one. I migrated the machine into a QEMU-KVM environment and performance got much better, but still far from ideal. Instead of 15:35:50 (usr:sys:idl), I got something like 70:30:0 (usr:sys:idl). (So there was no inexplicable idle time. But still quite a lot of kernel overhead.)Hard to say. Some virtualized environments have bugs that confuse the operating system.
Sure, but I'm definitely not the only one who runs OpenSolaris on an SMP virtual machine. So either Google would be full of reports on this (which is not the case), or there must be something wrong only with my system (either host or guest). Just trying to figure out what it is...
Is this a known issue? Is there a solution? Could I diagnose it with DTrace somehow? A piece of advice would be very helpful.You can use DTrace to profile the kernel. # dtrace -n 'profile-1997hz { @a[stack(50)] = count();} END { trunc(@a, 30); }' The above will show you the 30 most common kernel stacks. That might be a start.
# dtrace -n 'profile-1997hz { @a[stack(50)] = count();} END { trunc(@a, 30); }'
dtrace: description 'profile-1997hz ' matched 2 probes
dtrace: processing aborted: Abort due to systemic unresponsiveness
:-( Houston, we've had a problem...
Andrej
smime.p7s
Description: S/MIME Cryptographic Signature
_______________________________________________ perf-discuss mailing list perf-discuss@opensolaris.org
