kernprof
[Top] [All Lists]

Kernprof repeatability

To: kernprof@xxxxxxxxxxx
Subject: Kernprof repeatability
From: reeja.john@xxxxxxx
Date: Fri, 26 Oct 2001 09:54:25 -0700
Cc: kotaeji@xxxxxxxxxxxxx
Sender: owner-kernprof@xxxxxxxxxxx
Hi,
    I am running kernprof-1.2.2 on linux 2.4.6. to find out cpu  utilization
of  certain kernnel tcp/ip stack functions.I run kernprof on a http server
machine and downloaded the same web page from a client machine connected  to
server through a swich.Test is repeated each time rebooting the both
machines and clearing the browser disk cache every time.I was noting the
time taken by kernel functions tcp_sendmsg and tcp_recvmsg eaching
time.These timings are varying a lot on each time eventhough I am running
the test at similar conditions all the time.I am putting my resuts below.Why
timing are varying this much ,when I run kernprof each time.If that is the
case, how can I calculate the actual cpu utilization of stack?Can I get more
accurate time if I use more recent versuns of linux kernel and kernprof?

Any help appreciated.
Thanks,
Reeja

On http server machine 

Test 1
tcp_sendmsg     #1379   17.79 us
tcp_recvmsg     #2      241.33 us 

Test 2
tcp_sendmsg     #1379   8.08 us 
tcp_recvmsg     #2      253.42 us 

Test 3
tcp_sendmsg     #1379   1.69 us 
tcp_recvmsg     #2      241.66 us 

Test 4
tcp_sendmsg     #1379   9.35 us 
tcp_recvmsg     #2      219.77 us 

Test 5
tcp_sendmsg     #1379   6.66 us 
tcp_recvmsg     #2      110.01 us 




<Prev in Thread] Current Thread [Next in Thread>
  • Kernprof repeatability, reeja . john <=