Experiences Getting SystemTap work on OLPC Machine

[William Cohen]

William Cohen wrote:

> This particular script attempts to determine the amount of the time
> spent in the power saving halted mode. It will run until control-c is
> typed on the command line. When control-c is pressed, the script
> prints out information about how long it ran, the number of entries
> and exits from halt state, and some statistics about the time spent in
> halted state. Below is the output of idle1.stp running on a idle
> machine running the 314 build and the q2b76 rom:
> 
> Starting halt watch
> Ran for 60544934 us
> entered default_halt 9609
> exited default_halt 9609
> percent halted: 17
> count: 9609
> avg_time: 1081
> min_time: 3
> max_time: 3429
> usec                distribution
> value |-------------------------------------------------- count
>     0 |                                                      0
>     1 |                                                      0
>     2 |                                                     18
>     4 |@                                                   219
>     8 |@                                                   295
>    16 |                                                     56
>    32 |@                                                   279
>    64 |                                                    149
>   128 |                                                    147
>   256 |@                                                   275
>   512 |@@@                                                 542
>  1024 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@  7605
>  2048 |                                                     24
>  4096 |                                                      0
>  8192 |                                                      0
> 
> This data show that the script was run for about 1 minute
> (60,544,934us).  There were about 9600 halt entries and exits. The
> time actually spent halted is surprisingly small, 17% for the unloaded
> machine. The average time spent halted is slightly over
> 1millisecond. One can see the distribution on the histogram.

Hi All,

There may be more interrupts on this system than a stock system. There were a 
couple additions to the stock hardware:

-Linksys USB200M usb to ethernet adapter
-4GB USB flash as root file system
	Memorex  Mini TravelDrive 6.51 PQ: 0 ANSI: 0 CCS

-Will