On Monday 08 December 2008 02:25:50 Avi Kivity wrote: > Rusty Russell wrote: > > This changes cpus_hardware_enabled from a cpumask_t to a cpumask_var_t: > > equivalent for CONFIG_CPUMASKS_OFFSTACK=n, otherwise dynamically allocated. > > > > > > -static cpumask_t cpus_hardware_enabled; > > +static cpumask_var_t cpus_hardware_enabled > > This isn't on stack, so it isn't buying us anything.
It's the CONFIG_NR_CPUS=4096 but nr_cpu_ids=4 case which we win using dynamic allocation. Gotta love distribution kernels. > Is the plan to drop cpumask_t? Yes. And undefine 'struct cpumask' if CONFIG_CPUMASK_OFFSTACK. That will stop assignment and on-stack declarations for all but the most determined. > If so, we're penalizing non-stack users > by forcing them to go through another pointer (and cacheline). Not quite. If !CONFIG_CPUMASK_OFFSTACK, cpumask_var_t == cpumask_t[1]. Blame Linus :) Cheers, Rusty. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
