Re: [PATCH 1/7] Simple Performance Counters: Core Piece

From: Christoph Lameter
Date: Fri Aug 17 2007 - 16:42:18 EST


On Fri, 17 Aug 2007, Mathieu Desnoyers wrote:

> Actually, get_cycles() at least on some AMD cpus, do not synchronize the
> core, which can skew the results. You might want to use
> get_cycles_sync() there.

get_cycle() results as used here are bound to a single processor. If we
end up on a different processor at the end of the measurement then the
result is discarded. So not need for get_cycles_sync.

-
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/