On Dec 5 2012 2:16 AM, EBo wrote: > On Dec 4 2012 9:06 AM, Kent A. Reed wrote: >> >> In addition to latency-test there is a script called "latencyplot" >> that >> possibly could give some insight. I have spent time staring at the >> rolling plot trying to discern regularities in the jitter (like when >> I >> suspect a BIOS and SMI are doing some fancy footwork). >> >> I had conjectured on emc-users about how one might go about making >> an >> external pulse-train analyzer which, like Michael's digital logic >> analyzer, would be able to generate histograms but over a longer >> time >> scale. If one is satisfied that the internal, latency-test approach >> provides a reasonable metric, then it would be dead-simple to take >> latency-test/latencyplot a step further, bin the results, and derive >> interesting measures from it. Like latency-test, one could provide a >> running tally of key measures or like the OSADL does for its >> RT-Preempt, >> one could draw histograms and analyze exhaustively on demand. > > I'm not a statistician, but have been involved with some wicked cool > statistical analysis projects in the distant past. I wonder if there > is > anyone in the group who knows how to use R well enough to help design > and set up a study to tease out various things like outliers, the > spectral density, ... I am not sure what all, but that would be a > formal > way to get at what you are talking about. The nice thing is that R > might already have the nasty bits like sapa, quantspec, spectralGP, > or > possibly BaSAR. I'm not realistically going to have the time to > delve > into this, but thought I would throw out the idea...
I just had an idea... Could someone with access to really good, ok, and ugly latency numbers set up a couple of long term data sets (say from 2 to 24 hours) to possibly hand off to someone to poke at? Basically I would be looking at 3 to 6 canonical datasets which are considered as good, acceptable, and unacceptable for for setting up/testing a general method of analysis. EBo -- ------------------------------------------------------------------------------ LogMeIn Rescue: Anywhere, Anytime Remote support for IT. Free Trial Remotely access PCs and mobile devices and provide instant support Improve your efficiency, and focus on delivering more value-add services Discover what IT Professionals Know. Rescue delivers http://p.sf.net/sfu/logmein_12329d2d _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
