Messages in this thread | | | Subject | Re: [PATCH] perf_events: fix and improve x86 event scheduling | From | Peter Zijlstra <> | Date | Mon, 14 Nov 2011 17:00:06 +0100 |
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On Mon, 2011-11-14 at 15:26 +0100, Stephane Eranian wrote: > There is an edge from the source to all the events. > There is an edge from all the counters to the sync. > There is an edge between an event and a counter, if > it can count the event. > > The capacity of any edge is 1.
Ah indeed.
So that gives:
E = e+e*c+c ~= O(c^2); since e<=c V = 2+e+c ~= O(c)
Then going by:
http://en.wikipedia.org/wiki/Maximum_flow_problem
we have to stay away from Edmonds-Karp.
Ford-Fulkerson would end up being O(E * c) = O(c^3), since max |f| is c. Which is pretty much identical to all these O(V^2 E) = O(c^3) as well.
Dinitz blocking flow with dynamic trees looks more interesting at O(c^2 log(c)). Push relabel with dynamic trees looks to be best at O(c^2), since V^2/E ends up being c^2/c^2 = 1.
Creating the graph itself will be O(c^2) as well, due to E.
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