Re: Integrate delay accounting with systemtap?

[Ananth N Mavinakayanahalli <ananth at in dot ibm dot com>]

On Thu, Jul 12, 2007 at 10:13:16AM -0400, Frank Ch. Eigler wrote:
> Ananth N Mavinakayanahalli <ananth@in.ibm.com> writes:
> 
> > [...]  We shouldn't be using any probes or functions in kernel for
> > this feature. Rather, SystemTap should be taught to listen to the
> > netlink socket where this information is available.
> 
> What do you mean by "listen to the netlink socket"?  The netlink
> widget is (roughly speaking) a way for user-space programs to run
> kernel queries outside the many other available methods.  But
> systemtap scripts already run in kernel space.  How/why would you want
> them to talk across netlink sockets?

See Documentation/accounting/getdelays.c

Given the data is available without any additional kernel probe/hook, it
would be good for SystemTap to do something similar to getdelays.c

Ananth