From: Ingo Molnar <mingo@xxxxxxx> Date: Tue, 26 Aug 2008 09:22:20 +0200 > And i guess the next generation of 4K CPUs support should just get away > from cpumask_t-on-kernel-stack model altogether, as the current model is > not maintainable. We tried the on-kernel-stack variant, and it really > does not work reliably. We can fix this in v2.6.28. I recenetly did some work on sparc64 to use cpumask pointers as much as possible. The only case that didn't work was due to a limitation in arch interfaces for the new generic smp_call_function() code. It passes a cpumask_t instead of a pointer to one via arch_send_call_function_ipi(). But other than that, the whole sparc64 SMP stuff uses cpumask_t pointers only. What it comes down to is that you have to do the "self cpu" and other tests in the cross-call dispatch routines themselves, instead of at the top-level working on cpumask_t objects. Otherwise you have to modify cpumask_t objects and thus pluck them onto the stack where they take up silly amounts of space. -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
