lkml.org 
[lkml]   [2015]   [Feb]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2] ARM: smp: Only expose /sys/.../cpuX/online if hotpluggable
On 02/13/15 12:20, Simon Horman wrote:
> Hi Stephen,
>
> On Fri, Feb 13, 2015 at 10:06:39AM -0800, Stephen Boyd wrote:
>> diff --git a/arch/arm/mach-shmobile/smp-r8a7779.c b/arch/arm/mach-shmobile/smp-r8a7779.c
>> index 3f761f839043..b45206f93ddf 100644
>> --- a/arch/arm/mach-shmobile/smp-r8a7779.c
>> +++ b/arch/arm/mach-shmobile/smp-r8a7779.c
>> @@ -124,19 +124,12 @@ static int r8a7779_cpu_kill(unsigned int cpu)
>>
>> return 0;
>> }
>> -
>> -static int r8a7779_cpu_disable(unsigned int cpu)
>> -{
>> - /* only CPU1->3 have power domains, do not allow hotplug of CPU0 */
>> - return cpu == 0 ? -EPERM : 0;
>> -}
>> #endif /* CONFIG_HOTPLUG_CPU */
>>
>> struct smp_operations r8a7779_smp_ops __initdata = {
>> .smp_prepare_cpus = r8a7779_smp_prepare_cpus,
>> .smp_boot_secondary = r8a7779_boot_secondary,
>> #ifdef CONFIG_HOTPLUG_CPU
>> - .cpu_disable = r8a7779_cpu_disable,
>> .cpu_die = shmobile_smp_scu_cpu_die,
>> .cpu_kill = r8a7779_cpu_kill,
>> #endif
> Its not clear to me why r8a7779_cpu_disable() has been
> removed rather than replaced by r8a7779_cpu_can_disable()

By default ARM's smp.c assumes that CPU0 can't be hotplugged. The
function is redundant. I guess I should have mentioned that in the
commit text.

--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project



\
 
 \ /
  Last update: 2015-02-13 21:41    [W:0.095 / U:0.124 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site