Re: [RFC][PATCH 0/5] NFS: trace points added to mounting path

[fche@redhat.com (Frank Ch. Eigler)]

Trond Myklebust <trond.myklebust@fys.uio.no> writes:

> [...]  As I understand it, you are not only proposing to make that
> filter extremely fine (individually addressable trace points), but
> also to enable the application of scripting tools like systemtap and
> LTTng in order to provide bespoke debugging of your customer
> problems. Have I misunderstood you, or is that correct?

Perhaps.

> The question then is how is this going to work out in an environment
> where the individually addressable trace points/dprintk()s pop in
> and out of existence at the whim of a patch, and where the output
> format is similarly volatile?

It would work no worse than what there is now.  For environments where
the code is not subject to that much patching, it could be
piggybacked-upon for more analysis.

> IOW: I'm referring to the difference between an interface that was
> designed purely to be interpreted by humans, and one that is
> designed from scratch to be interpreted by scripts.

It need not be a disjunction.  As more formal machine-oriented
interfaces come into existence, the same tools can shift focus to
them.  Depending on the tool, the shift may be nearly invisible to a
naive end user.


- FChE