Re: [...] kprobes [minutes] portion 20060406

[Richard J Moore <richardj_moore@uk.ibm.com>]

systemtap-owner@sourceware.org wrote on 07/04/2006 09:25:17:

>
> On Thu, Apr 06, 2006 at 05:28:38PM -0400, Frank Ch. Eigler wrote:
> > Hi -
> >
> > On Thu, Apr 06, 2006 at 02:14:46PM -0700, Hien Q Nguyen wrote:
> > > User space probe
> > > Prasanna had prototype that execute the handler in the user space
[...]
> >
> > Beyond merely dispatching, it is important to consider what such a
> > handler can do.  Would it still be useful if it cannot call into the
> > kernel-side runtime, if it cannot share variables with kernel-space
> > probes?
>
> No. The purpose of prototype was to see how it can be implemented.
> To my opinion having handler run in user-space does not suit well for
> system-wide tracing. But that might be one of the alternative approaches
> to per-process tracing, since ptrace is found to have more performance
> related problems.
>
>
 Agreed, but don't let the creation of per-process probe handlers detract
from the argument for a system-wide capabiltiy; that's the real
battle-ground.

Richard


> Thanks
> Prasanna
> --
> Thanks & Regards
> Prasanna S Panchamukhi
> Linux Technology Center
> India Software Labs, IBM Bangalore
> Email: prasanna@in.ibm.com
> Ph: 91-80-51776329