On Wednesday 05 December 2012 06:02:20 EBo did opine: > 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 --
This brought up a renewed desire to let latencyplot run for a few hours, but it took 10 minutes worth of cleanup with rmmod to get rid of the leftovers from the last session several days ago. It needs to clean up after itself when it exits. > > ------------------------------------------------------------------------ > ------ 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 Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! Men are those creatures with two legs and eight hands. -- Jayne Mansfield I was taught to respect my elders, but its getting harder and harder to find any... ------------------------------------------------------------------------------ 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
