Messages in this thread | | | Date | Tue, 09 Nov 2004 07:29:46 +1100 | From | Con Kolivas <> | Subject | Re: SCHED_RR and kernel threads |
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Stephen Warren wrote: > Hello. > > We have an application that is running on kernel 2.6.9. This application > makes use of real-time threads, namely using the SCHED_RR policy. > > It appears that during times of high application CPU usage, some > *kernel* threads don't get to run. As an example, this means that local > keyboard presses aren't processed (or are processed very slowly) by the > kernel, so our application never sees them. This has the effect of > hanging the system, since the way to get out of the higher CPU usage > portion of the application is to press the ESC key, and our application > never sees that keypress. > > This appears to be due to the fact that the kernel threads are all > SCHED_OTHER, so our SCHED_RR user-space application trumps them!
Don't run your userspace at SCHED_RR? The kernel threads are SCHED_NORMAL precisely for the reason that you wont get real time performance if the kernel threads rear their ugly heads, albeit rarely.
Cheers, Con [unhandled content-type:application/pgp-signature] | |