On Monday, February 13, 2012 07:27:42 AM Mark Wendt did opine: > On 02/12/2012 01:12 PM, gene heskett wrote: > >> Gene, > >> > >> About tracking that occasional blip on the isolcpu, have you used > >> atop? Consider it a "top" on steroids. It shows processes running > >> much like top, but also displays what cpu they are running on. > >> Here's the atop web site: http://www.atoptool.nl > >> > >> Click on the screen shots and take a peek at what atop has over the > >> top utility. I use it at work. > >> > >> Mark > > > > This prompted me to do a little more experimenting between running it > > as lcnc, which is a script that does the taskset, and running it as > > linuxcnc which does not. Then either way atop did not detect enough > > activity on the 2nd cpu to bother listing it more than 5% of the > > time. In that regard, htop, which displays each cpu it is configured > > for, full time as a slider in the upper area of its screen. To me, > > htop is the better utility, but then I am used to it and have been > > using it for years on this box full time. > > > > ksysguard OTOH used for the rest of this testing, showed a higher cpu > > usage overall for both cpu's and cpu001 was consistently in the > > 50-60% range when taskset was in effect, and about a 20% less total > > when it was not, only with possibly an 8% peak for #1 while it was > > running a 20 minute program with the motors off. > > > > Which of these two monitors utils is correct, I'll have to plead the > > 5th on as I don't have a clue. > > > > Then I thought I'd see how fast I can run the base thread, starting to > > hit realtime delays when taskset was used at about 17 microseconds, > > and pretty consistently at 14 microseconds, and when taskset was not > > used, I could go down another microsecond, perhaps 2. Without > > taskset, and at 19 microseconds, it has now run that 20 minute > > program 3 times without a delay warning thrown. > > > > This of course is without the local and slower gfx delays that > > relatively poor intel gfx chip will cause when it is using its own X > > to display the axis output. Hooking up my lappy, and ssh-ing into it > > so as to use the laptops gfx, probably wouldn't be quite that > > advantageous as its an ati gfx chipset and only a 1.4Ghz 'turion', > > but I'd think, until I observe otherwise, that what I'd see would be > > laggy gfx if the miss-match was too great. > > > > I guess what I'm saying is that in the overall scheme, using taskset > > isn't the magic twanger I thought it might be. The gfx in use, from > > this testing would seem to have the more noticeable effect. I will, > > very occasionally hit a realtime delay when running on its own x > > server& local screen with a 20 microsecond base thread when using > > taskset. Konversation is running, but firefox is not, kcalc and > > update_manager are but neither of the last are using detectable cpu. > > > > When I installed atop, it started an atop daemon, but I have no clue > > if it is actually active and collecting data when the display isn't > > running, in any event I just now used htop to run it down& send it a > > quit signal just in case. > > > > htop, FWIW, is showing cpu1 at around .5% so it must be using the same > > mechanism as atop to collect the data. As this HAS to be a bit > > intrusive, its possible it might cost a microsecond in base thread > > time to actually collect the data. I don't normally run it, or > > ksysguard, on that box since the gfx for ksysguard would have to > > impinge on the rest of the system. > > > > Conclusion? Forget taskset, and export the display to a remote server > > for best realtime performance. I believe that is the same conclusion > > some of you have reached. However, the improvement wouldn't seem to > > warrant the sheckels to buy another of those boxes and a display, > > territory of $375 additional cost, although that box could probably > > boot from a usb key and wouldn't need a dvd writer, bringing that > > back down to perhaps $300. Still not worth the minuscule improvement > > IMO. > > > > Thanks Mark. > > > > Cheers, Gene > > Gene, > > Yeah, atop does run as a daemon collecting info in the background. If > you crank up atop on the command line with the -s switch, you get a neat > screen which shows what CPU the process is running on. On my Ubuntu > 11.10 with a quad core, I see processes occasionally running on all > four. > > Mark > I'll give the -s switch a try when I'm awake for good. Thanks.
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 it NOUVELLE CUISINE when 3 olives are struggling with a scallop in a plate of SAUCE MORNAY? ------------------------------------------------------------------------------ Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-dev2 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
