Subject: Re: [PATCH][RFC] Infrastructure for compact call location representation

From: Nick Piggin <[email-masked]>
Date: Wed, 9 Jun 2010 18:44:17 +1000

On Tue, Jun 08, 2010 at 08:44:56AM -0700, Stephen Hemminger wrote:
> On Mon, 7 Jun 2010 17:30:52 -0700
> David VomLehn <[email-masked]> wrote:
> > History
> > v2	Support small callsite IDs and split out out-of-band parameter
> > 	parsing.
> > V1	Initial release
> > 
> > Signed-off-by: David VomLehn <[email-masked]>
> 
> This is really Linux Kernel Mailing List material (not just netdev). And it will
> be a hard sell to get it accepted, because it is basically an alternative call
> tracing mechanism, and there are already several of these in use or under development
> (see perf and ftrace).

What about a generic extension or layer on top of stacktrace that
does caching and unique IDs for stack traces. This way you can get
callsites or _full_ stack traces if required, and it shouldn't require
any extra magic in the net functions.

You would need a hash for stack traces to check for an existing trace,
and an idr to assign ids to traces.