From: Ingo Molnar <mingo@xxxxxxx> Date: Fri, 5 Dec 2008 09:42:33 +0100 > Please let me repeat: it's a _fundamental_ thesis of performance > instrumentation to not disturb the monitored context. Your insistence on > _stopping_ the monitored task breaks that fundamental axiom! This is only a problem if you make your measurement quantums too small. Furthermore, there are multiple registers and states to update atomically when a perf counter overflows. You're read/write thing just doesn't cut it, especially for certain kinds of hardware. It's really a utopian view of the world. :) -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
