Re: Simplifying examples by improving vfs tapset

[William Cohen <wcohen at redhat dot com>]

Jeff Moyer wrote:

> What about readv and writev?  I had modified my local copy of
> disktop.stp to take these into account (hooking into do_readv_writev).
> I will post those updates if you like, once I figure out why I ran into
> a problem with the array assignments.  (I had to read from the io_stat
> array before writing to it, otherwise the written values didn't show
> up.)

I didn't modify the vfs.readv and vfs.writev in the patch. However, it looks 
like the same dev and ino variables could be made available for vfs_writev and 
vfs_readv.

> One other improvement that could be made to the script is AIO support.

There is an example that examines rescheduling during AIO operations:

http://sources.redhat.com/git/gitweb.cgi?p=systemtap.git;a=blob;f=testsuite/systemtap.examples/io/io_submit.stp;

What additional support do you see needed for AIO?

-Will