Subject: fscked clock sources revisited

From: jamal <[email-masked]>
Date: Mon, 30 Jul 2007 21:10:39 -0400

Folks,

I have posted this before but got no good response and i havent had time
to chase it. 
While doing some batching tests with pktgen and then with a simple
client server app with udp, it does appear that the clock source used
matters. Here are some basic runs with plain vanilla 2.6.22-rc4 runs
with udp. There are five runs per clock source and each result is in
Mbps.

acpi_pm: 108, 110, 111,  91, 108
tsc:     143, 108, 161, 129, 108
jiffies: 132, 138, 132, 146, 150

jiffies produces better results than tsc which produces better results
than acpi_pm. 

Second issue: I cant consistently get two reboots to always boot with
the same clock source.

Any ideas whats going on here? I havent tried with latest tree.

PS:- These results are very easy to validate with iperf or netperf.

cheers,
jamal