analysis of polling in systemtap

[Martin Hunt]

On Mon, 2005-12-19 at 11:58 -0800, Martin Hunt wrote:

> >      # there is also a race here.
> >      delete called
> 
> Yes, this is a much more serious race. 

I shouldn't have said that.  It is only more serious if you consider the
problem of dueling timer probes printing the same data at the same time,
which isn't something I plan to worry about.

The real problem I want to solve is how to better handle timer events
that print data and then clear a pmap. Because clearing a large pmap can
be expensive and could be done for free while aggregating it.

> The best way to fix this from an efficiency and reliability
> point of view is to simply add another flag to the runtime print and
> aggregation commands to clear the map as it is printed. I don't have any
> good ideas about how this would made part of the systemtap language.
> 
> Martin
> 
>