On Sat, 2009-02-14 at 07:46 +1030, Rusty Russell wrote: > On Thursday 12 February 2009 22:39:14 Peter Zijlstra wrote: > > So it put in unconditionally, how about this? > > > > > > -- > > Subject: generic-smp: remove single ipi fallback for smp_call_function_many() > > > > In preparation of removing the kmalloc() calls from the generic-ipi code > > get rid of the single ipi fallback for smp_call_function_many(). > > > > Because we cannot get around carrying the cpumask in the data -- imagine > > 2 such calls with different but overlapping masks -- put in a full mask. > > OK, if you really want this, please just change it to: > unsigned long cpumask_bits[BITS_TO_LONGS(CONFIG_NR_CPUS)]; > > The 'struct cpumask' will be undefined soon when CONFIG_CPUMASK_OFFSTACK=y, > which will prevent assignment and declaration on stack. > > I'd be fascinated to see perf numbers once you kill the kmalloc. Because > this patch will add num_possible_cpus * NR_CPUS/8 bytes to the kernel which > is something we're trying to avoid unless necessary. You're free to make it a pointer and do node affine allocations from an init section of choice and add a hotplug handler. But I'm not quite sure how perf is affected by size overhead on ridiculous configs. -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
