![]() | |||||||||||||
Messages in this thread
|
> work-around-ppc64-bootup-bug-by-making-mutex-debugging-save-restore-irqs.patch > kernel-kernel-cpuc-to-mutexes.patch > > ug. We cannot convert the cpu.c semaphore into a mutex until we work out > why power4 goes titsup if you enable local interrupts during boot. What is the exact problem ? Some mutex is forcing local irqs enabled before init_IRQ() ? (Before the normal enabling of IRQ done by init/main.c just after init_IRQ() more precisely ?) This is bad for any architecture. Basically, at this point, the interrupt controller can be in _any_ state, with possible pending interrupts for whatever sources, etc... As we discussed before, that problem should really be fixed in the mutex code by not hard-enabling. There is an incredible amount of crap that could be cleaned up for example by re-ordering a bit the init code and making things like slab available before init_IRQ/time_init etc... but all of those will break because of that. In addition, even without that re-ordering, I'm pretty sure we are hitting semaphores/mutexes early, before init_IRQ(), already and if not in generic code, in arch code somewhere down the call stacks. I don't think that whole pile of problems lurking around the corner is worth the couple of cycles saved by hard-enabling irq in the mutex instead of doing a save/restore. Ben. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ | ||||||||||||
| Last update: 2006-06-07 05:55 [from the cache] ©2003-2008 | |||||||||||||