Re: [RFC PATCH 4/5] mm: Add hit/miss accounting for Page Cache

[Ingo Molnar <mingo@elte.hu>]

* Dave Hansen <dave@linux.vnet.ibm.com> wrote:

> On Wed, 2011-03-02 at 09:45 +0100, Ingo Molnar wrote:
> > But, instead of trying to improve those aspects of our existing instrumentation 
> > frameworks, mm/* is gradually growing its own special instrumentation hacks, missing 
> > the big picture and fragmenting the instrumentation space some more.
> > 
> > That trend is somewhat sad. 
> 
> Go any handy examples of how you'd like to see these done?

There's a very, very old branch in tip:tracing/mm (by Steve) that shows off some of 
the concepts that could be introduced, to 'dump' current MM state via an extension 
to the tracepoints APIs:

3383e37ea796: tracing, page-allocator: Add a postprocessing script for page-allocator-related ftrace events
c33b3596bc38: tracing, page-allocator: Add trace event for page traffic related to the buddy lists
0d524fb734bc: tracing, mm: Add trace events for anti-fragmentation falling back to other migratetypes
b9a28177eedf: tracing, page-allocator: Add trace events for page allocation and page freeing
807243eb20b2: Merge branch 'perfcounters/urgent' into tracing/mm
08b6cb88eeb5: perf_counter tools: Provide default bfd_demangle() function in case it's not around
eb4671011887: tracing/mm: rename 'trigger' file to 'dump_range'
1487a7a1ff99: tracing/mm: fix mapcount trace record field
dcac8cdac1d4: tracing/mm: add page frame snapshot trace

That's just a demo in essence - showing what things could be done in this area.

You can pick those commits up via running:

  http://people.redhat.com/mingo/tip.git/README

Thanks,

	Ingo