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 =E2=80=9CSUM=E2=80=9D to captur= e 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 =E2=80=9CTime=E2=80=9D utility and the Dtrace s= cript 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 =3D=3D "ping"/ { self->ts =3D timestamp; } sched:::off-cpu /self->ts !=3D 0/ { @delta[curthread->td_name] =3D sum(timestamp - self->ts)/1000000; self->ts =3D0; } Looking forward to hear from you. Regards Abhishek kulkarni
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