Re: simple (dumb) script to track sizes of IOs

[Badari Pulavarty <pbadari at us dot ibm dot com>]

Frank Ch. Eigler wrote:
> pbadari wrote:
>
>
> > Here is a simple systemtap script to track the sizes of IOs 
> > that are getting generated (to the driver).
>
>
> That's block i/o only right?

Yes.

> > [...]
> > Is there a way, I can print in the order of IO sizes easily ?
>
>
> There will be a way of iterating in a sorted order, probably
> expressed syntactically like this:



> # function report () {
> #   foreach (ascending(io) in iosizes) {
> #         if (iosizes[io]) # ...
> # }

Does this functionality exists today ?

> > [...]# stap -g iosizes.stp [...]
>
>
> Your script does not need guru mode.  Merely reading $rq->nr_sectors
> is fine without that.  You also don't need to check "if (iosizes[io])"
> since zero-valued array elements do not appear in foreach()
> iterations.

Thanks. Is there some documentation on the allowed syntax and
library functions ?

Thanks,
Badari