On May 10, 2010, at 8:40 AM, Les Mikesell lesmikesell@gmail.com wrote:
JohnS wrote:
On Sun, 2010-05-09 at 21:46 -0400, Ross Walker wrote:
On Sat, May 8, 2010 at 7:38 PM, JohnS jses27@gmail.com wrote:
On Sat, 2010-05-08 at 16:17 -0400, Ross Walker wrote:
On May 8, 2010, at 8:35 AM, Mag Gam magawake@gmail.com wrote:
At our Physics research labs we do a lot with low latency networks. We have been using Centos for over 3 years now and its been great! We would like to tune and optimize our setup by removing unneeded packages -- kernel modules to be specific. I was wondering, how does one measure the speed of the kernel. Is that even possible?
Use oprofile.
-Ross
Ross, never mind I just yummed it onto a machine there faq is inheritly wrong.
The FAQ is only correct in respect to the project's view.
Redhat has a custom oprofile that works with their custom kernels, so stock oprofile from the project's site IS incompatible, but that's OK cause RH provides one that works with their distro.
-Ross
Correct as i found out.
Would this also be suitable for testing efficiency loss from running under VMware or other virtualization methods?
No because oprofile and latencytop's point of reference is just the running kernel and doesn't factor in CPU allocations, network/disk virualization/para-virtualization, bandwidth allocations, etc.
Efficiency loss is a slippery slope and VERY configuration dependant.
I have seen VMs perform better than physical machines and I have seen them perform worse, sometimes on the same physical host!
Go with the "user experience" indicator (assuming it is properly configured for the workload). Does it seem fast? Then it's fast. Does it seem slow? Then it is slow.
-Ross