Date: Tue, 16 Jun 2015 11:01:27 -0700 From: abhishek kulkarni <abhya007@gmail.com> To: freebsd-dtrace@freebsd.org Subject: Regarding a Sched Dtrace Script for FreeBSD Message-ID: <CAJUVset6fHUGkbgLmd-iGRmaRzD9ZBt5wjMkeec9vW2bmnph0g@mail.gmail.com>
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Hello all,
I am working on Dtrace and trying to implement a sched script for FreeBSD
10.0
The script uses the probes on-cpu and off-cpu.
The purpose is to measure the time that a CPU spends on the current thread.
I am trying to use the aggregation function “SUM” to capture the CPU time
for the ping utility. I am doing it by opening a new putty terminal and
running the ping utility in it, and then running the Dtrace script in
another instance of the terminal.
I am also using the time utility in order to verify the Kernel Time for a
ping. The time given by the “Time” utility and the Dtrace script do not
match. Could you please help with this . The following is the Dtrace script
we are trying out :
sched:::on-cpu
/curthread->td_name == "ping"/
{
self->ts = timestamp;
}
sched:::off-cpu
/self->ts != 0/
{
@delta[curthread->td_name] = sum(timestamp - self->ts)/1000000;
self->ts =0;
}
Looking forward to hear from you.
Regards
Abhishek kulkarni
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