On Tue, 2005-07-12 at 18:46 -0700, Paul E. McKenney wrote: > > If you are talking about scheduler_tick, then yes, it is called by the > > timer interrupt which is a SA_NODELAY interrupt. If you don't want to > > get interrupted by the timer interrupt, then you will need to disable > > interrupts for both. Since currently, the timer interrupt is the only > > true hard interrupt in the PREEMPT_RT and that may not change. > > OK, so if I take a spinlock in something invoked from scheduler_tick(), > then any other acquisitions of that spinlock must disable hardware > interrupts, right?
Yes, otherwise you could have a local CPU deadlock on a SMP machine. And I would also say the same is true for any lock that is grabbed by the timer interrupt or one of the functions it calls. -- Steve - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
