* Daniel Eischen <[EMAIL PROTECTED]> [071002 20:02] wrote: > On Tue, 2 Oct 2007, Alfred Perlstein wrote: > > >* Daniel Eischen <[EMAIL PROTECTED]> [071002 19:46] wrote: > >>On Tue, 2 Oct 2007, Alfred Perlstein wrote: > >> > >>>Hi guys, we need critical sections for userland here. > >>> > >>>This is basically to avoid a process being switched out while holding > >>>a user level spinlock. > >> > >>Setting the scheduling class to real-time and using SCHED_FIFO > >>and adjusting the thread priority around the lock doesn't work? > > > >Too heavy weight, we want to basically have this sort of code > >in userland: > > Well, yeah, but are you _really_ sure that you aren't just > running something that should be real-time and have priority > over other applications? SCHED_FIFO means you will run until > you relinquish the CPU (you can only do this as root). If > all your threads are well behaved, would this work? Have > you tried it?
No, because it wouldn't work. How do we know when to let go of the cpu? In my system, the kernel tells you without polling. > > Are you trying to prevent switching out of the thread > amongst other threads of the same application, or all > threads in the system? All threads on that CPU. It's basically, almost like a "soft spl" for userland. Right? -- - Alfred Perlstein _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
