On Mon, Jan 26, 2009 at 12:51 PM, Jon Masters <jcm@xxxxxxxxxx> wrote: > On Sun, 2009-01-25 at 14:52 -0800, Mike Kravetz wrote: > >> Any reason why you could not do SMI detection in user level code running >> at the highest RT priority? > > Yeah. I had some suggestions about that already...the problem with that > is that you can't know whether measured latencies are due to SMIs /or/ > other kernel latencies - maybe there's a bug or other problem? I really > want to be able to say to vendors "nope, it's definitely your problem". Can't you do this with a known good version of the -rt kernel and the latency tracer in full RT preempt mode? SMI induced latency will show up in the trace as long delays in random code paths where kernel induced latency can be ruled out. Lee -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
