about systemtap cost

about systemtap cost

[Gareth]

Which case would cost more in runtime?

1. run "stap xyz.stp" which contains:

probe X {
    # do sth
}
probe Y {
    # do sth
}
probe Z {
    # do sth
}

2. run "stap x.stap" which contains:
probe X {
    # do sth
}

then, run "stap y.stap" which contains:
probe Y {
    # do sth
}

then, run "stap z.stap" which contains:
probe Z {
    # do sth
}



-- 
Gareth

Cloud Computing, OpenStack, Distributed Storage, Fitness, Basketball
OpenStack contributor, kun_huang@freenode
My promise: if you find any spelling or grammar mistakes in my email
from Mar 1 2013, notify me
and I'll donate $1 or ￥1 to an open organization you specify.

Re: about systemtap cost

[Frank Ch. Eigler]

academicgareth wrote:

> Which case would cost more in runtime?
> [... one script with three probes vs. three scripts with one probe each ...]

There should be no difference at a first-order level of analysis, so
do whatever makes more sense from a script life-cycle or data-sharing
or other such abstract concern.

(Second-order performance effects like cache locality probably slightly
favour putting the probes together into one script.)

- FChE