Re: [PATCH 3/3] x86: fix node_possible_map logic -v2

From: Alan Cox
Date: Mon May 11 2009 - 17:29:30 EST


> CPU [0-1] cannot be considered local in either node, since they are
> further away from the memory than either, and furthermore, unlike either
> of the memory nodes, they have no preference for memory from either of
> the other two nodes (quite on the contrary; they would probably benefit
> from drawing from both.)

Surely you should schedule based on the memory bandwidth at that point ?
Assuming the data collection overhead is acceptable. A long time ago
someone did a paper on a related topic (Scheduling by memory bandwidth on
the grounds that memory not CPU bandwidth was the resource most
constrained) and that demonstrated that for quite a few processors the
memory bandwidth data is cheaply available in the profiling registers.

Alan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/