Re: [PATCH/RFC 1/5] [PATCH] sched: merge cpu_to_core_group functions

Suresh Siddha
2010-08-13T21:12:34Z

On Thu, 2010-08-12 at 10:25 -0700, Heiko Carstens wrote:
> From: Heiko Carstens <heiko.carstens@de.ibm.com>
>
> Merge and simplify the two cpu_to_core_group variants so that the
> resulting function follows the same pattern like cpu_to_phys_group.
>
> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
> ---
>
> kernel/sched.c | 18 +++++-------------
> 1 file changed, 5 insertions(+), 13 deletions(-)
>
> diff -urpN linux-2.6/kernel/sched.c linux-2.6-patched/kernel/sched.c
> --- linux-2.6/kernel/sched.c 2010-08-11 13:47:16.000000000 +0200
> +++ linux-2.6-patched/kernel/sched.c 2010-08-11 13:47:22.000000000 +0200
> @@ -6546,31 +6546,23 @@ cpu_to_cpu_group(int cpu, const struct c
> #ifdef CONFIG_SCHED_MC
> static DEFINE_PER_CPU(struct static_sched_domain, core_domains);
> static DEFINE_PER_CPU(struct static_sched_group, sched_group_core);
> -#endif /* CONFIG_SCHED_MC */
>
> -#if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT)
> static int
> cpu_to_core_group(int cpu, const struct cpumask *cpu_map,
> struct sched_group **sg, struct cpumask *mask)
> {
> int group;
> -
> +#ifdef CONFIG_SCHED_SMT
> cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map);
> group = cpumask_first(mask);
> +#else
> + group = cpu;
> +#endif
> if (sg)
> *sg = &per_cpu(sched_group_core, group).sg;
> return group;
> }
> -#elif defined(CONFIG_SCHED_MC)
> -static int
> -cpu_to_core_group(int cpu, const struct cpumask *cpu_map,
> - struct sched_group **sg, struct cpumask *unused)
> -{
> - if (sg)
> - *sg = &per_cpu(sched_group_core, cpu).sg;
> - return cpu;
> -}
> -#endif
> +#endif /* CONFIG_SCHED_MC */
>
> static DEFINE_PER_CPU(struct static_sched_domain, phys_domains);
> static DEFINE_PER_CPU(struct static_sched_group, sched_group_phys);

Reason why this code was structured like this was because of the
feedback from Andrew Morton. http://lkml.org/lkml/2006/1/27/308

May be we can further clean all this code up as part of your new
proposal. I can help in some of this. Thanks.