From: Huacai Chen Date: Thu, 26 Jun 2014 11:41:25 +0800 Subject: [1/8] MIPS: Support hard limit of cpu count (nr_cpu_ids) Origin: https://git.kernel.org/linus/0f3f506b275517250ee0169ec075d5382967f5f6 On MIPS currently, only the soft limit of cpu count (maxcpus) has its effect, this patch enable the hard limit (nr_cpus) as well. Processor cores which greater than maxcpus and less than nr_cpus can be taken up via cpu hotplug. The code is borrowed from X86. Signed-off-by: Huacai Chen Reviewed-by: Andreas Herrmann Cc: John Crispin Cc: Steven J. Hill Cc: Aurelien Jarno Cc: linux-mips@linux-mips.org Cc: Fuxin Zhang Cc: Zhangjin Wu Patchwork: https://patchwork.linux-mips.org/patch/7183/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/setup.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c index a842154..2f01201 100644 --- a/arch/mips/kernel/setup.c +++ b/arch/mips/kernel/setup.c @@ -729,6 +729,25 @@ static void __init resource_init(void) } } +#ifdef CONFIG_SMP +static void __init prefill_possible_map(void) +{ + int i, possible = num_possible_cpus(); + + if (possible > nr_cpu_ids) + possible = nr_cpu_ids; + + for (i = 0; i < possible; i++) + set_cpu_possible(i, true); + for (; i < NR_CPUS; i++) + set_cpu_possible(i, false); + + nr_cpu_ids = possible; +} +#else +static inline void prefill_possible_map(void) {} +#endif + void __init setup_arch(char **cmdline_p) { cpu_probe(); @@ -752,6 +771,7 @@ void __init setup_arch(char **cmdline_p) resource_init(); plat_smp_setup(); + prefill_possible_map(); cpu_cache_init(); } -- 1.7.10.4