Notes from the systemtap BOF

[Maneesh Soni]

On Tue, Jul 26, 2005 at 02:33:19AM -0700, Spirakis, Charles wrote:

[..]
> 
> Potential useful places for tapsets and probes:
> 
> tapset for sysfs
> 
> blockio layer information. Infrastructure to pass around data. For
> example,
> open file (large file) and kernel translates to block on disk. At bio
> layer
> that block is all you see, want ability to correlate that block back to
> file name. Associative arrays could be useful for this. Large reserve
> buffer
> area, size of correlation data can be an issue.
> 

There was one more request (not discussed at BOF) related to IO layer
tracing. 

It is to get information about time taken in executing a probed routine. 
There should be some way to find out how much time (could be CPU cycles or 
human time) is taken in the executions of various routines in the code 
path. It could be useful in analysing IO stalls / hangs etc. 

I don't know if that is possible in systemTAP or not
but looks a nice feature to me.


Thanks
Maneesh