IO script

[Mike Mason]

Hi Wenji,

Thanks for the scripts.  Unfortunately, I don't think they measure actual physical seeks and random IO to disk.  For that, I think we have to probe the IO schedulers.  The scripts assume that physical IO's occur in the order requested, which isn't necessarily the case.

Also, as Srinivasa noted in bug 5231 today, bio_endio() no longer has a bytes_done variable as of 2.6.24-rc1 (Linus' git).  We'll need to update the ioblock tapset and your scripts to reflect that.

Mike

Wenji Huang wrote:
> Hi,
> 
>  Just as discussion at last conference call, Dtrace provides good 
> toolkit for users. see           
>       http://www.opensolaris.org/os/community/dtrace/dtracetoolkit/
>       http://prefetch.net/articles/solaris.dtracetopten.html
> 
>  If systemtap has same facility, it is very helpful to widen the use.
> 
>  Based on idea from Dtrace, I created two scripts which can illustrate 
> disk I/O status.
> 
>  Please kindly review it. If possible, we maybe collect/create some 
> useful stap scripts as toolkit embedded in source.
> 
> Regards,
> Wenji
>