Messages in this thread | | | Date | Tue, 28 Apr 2009 11:29:18 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH 5/5] proc: export more page flags in /proc/kpageflags |
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* 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
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