On Sun, 26 Jul 2009, Brent Busby wrote: > On Sun, 26 Jul 2009, Ken Restivo wrote: > >>> I've also run into a handful of config options that either help or hurt >>> realtime performance, depending on the specific hardware: >>> >>> NO_HZ (seems to work properly on most hardware these days) >> >> Is that advised? I was told to use HZ_1000 in order to get MIDI to work >> correctly. Should I be using NO_HZ instead? I've got several machines to >> configure: a 32-bit Atom EEE, a 64-bit Intel Micro-ITX, and a 64-bit Asus >> Intel Core2Duo > > Oddly (and I don't really understand this), you can have *both*. I've seen > recommendations online from people who claim to have gotten good results with > Jack even on laptops by having NO_HZ and HZ_1000 selected. I don't really > know what the effect of this is. Does this mean you generate no ticks except > when you need them, but when you do, the jiffy rate is 1000Hz? This naively > seems to me like a better idea than just running a clock all the time, but I > don't know how that pans out for recording and MIDI. Ahh. This explains why I've had good results with NO_HZ for the last year. I have both NO_HZ and HZ_1000 enabled. I still don't understand how these two interact. At the very least, this would provide the fallback for booting the kernel with nohz=off. > It seems like there ought to be more pooling of resources regarding complete > kernel configs that work. Everyone always talks about the patches > themselves...but anyone who can do 'patch -p1' against a tree of source code > can get that part right. > > -- > + Brent A. Busby + "We've all heard that a million monkeys > + UNIX Systems Admin + banging on a million typewriters will > + University of Chicago + eventually reproduce the entire works of > + Physical Sciences Div. + Shakespeare. Now, thanks to the Internet, > + James Franck Institute + we know this is not true." -Robert Wilensky I'm willing to post my config for the AMD laptop once I get the right combination of HZ, RTC, and HPET options set. I'm still running Fedora 8 on my Core2Quad, so I've stopped at 2.6.24.7-rt27 with everything running perfectly, but I can post the config from that box if anyone is interested. Cheers, --ww _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user
