[ltt-dev] [patch 7/9] LTTng instrumentation - kernel

[rusty@rustcorp.com.au (Rusty Russell)]

On Wednesday 25 March 2009 05:03:13 Ingo Molnar wrote:
> 
> (Rusty Cc:-ed - for the module.c tracepoints below)

Thanks, tho they look fine and non-intrusive to me.

> I believe that to have a complete picture of module usage, module 
> refcount get/put events should be included as well, beyond the basic 
> load/free events.
> 
> These both have performance impact (a module get/put in a fastpath 
> hurts scalability), and are informative in terms of establishing the 
> module dependency graph.

A module_get()/put() should not hurt scalability at all!  I went to great and
horrible lengths to ensure that was the case since the rewrite in 2.4.

But a module dependency graph et. al. would be kind of cool.

Thanks,
Rusty.