Re: [PATCH 5/5] proc: export more page flags in /proc/kpageflags

[Ingo Molnar <mingo@elte.hu>]

* Pekka Enberg <penberg@cs.helsinki.fi> wrote:

> I have no idea how expensive tracepoints are but I suspect they 
> don't make too much sense for this particular scenario. After all, 
> kmemtrace is mainly interested in _allocation patterns_ whereas 
> this patch seems to be more interested in "memory layout" type of 
> things.

My point is that the allocation patterns can be derived from dynamic 
events. We can build a map of everything if we know all the events 
that led up to it. Doing:

  echo 3 > /proc/sys/vm/drop_caches

will clear 99% of the memory allocations, so we can build a new map 
from scratch just about anytime. (and if boot allocations are 
interesting they can be traced too)

_And_ via this angle we'll also have access to the dynamic events, 
in a different 'view' of the same tracepoints - which is obviously 
very useful for different purposes.

	Ingo