On Fri, 13 Apr 2007 11:42:29 +1000 Nick Piggin <nickpiggin@xxxxxxxxxxxx> wrote:
Maybe. How about LRU? Reclaim performance is bad, and you want to work out
which pages keep going off the end of it, or which pages keep getting
written out via it, or who's pages are on the active list, forcing mine
out.
I guess we have static analysis versus dynamic. The interfaces which Matt
is proposing are suited to answering the question "what is my memory being
used for" (static). They're unlikely to be useful for answering the question
"what's happening in the VM" (dynamic). Systemtap is probably better for the
dynamic analysis.
I guess one could generate an answer to the static question with systemtap,
by accumulating running counts across the application lifetime and then
snapshotting them. Sounds hard though.