Re: [PATCH v2 2/2] x86: Added read_mostly declaration/definition to vars from smp.h

[Vlad <vlad@scalemp.com>]

On 05/18/2012 11:14 AM, Ingo Molnar wrote:
> * Vlad Zolotarov<vlad@scalemp.com>  wrote:
>
>> Added a "read-mostly" qualifier to the following variables in smp.h:
>>   - cpu_sibling_map
>>   - cpu_core_map
>>   - cpu_llc_shared_map
>>   - cpu_llc_id
>>   - cpu_number
>>   - x86_cpu_to_apicid
>>   - x86_bios_cpu_apicid
>>   - x86_cpu_to_logical_apicid
>>
>> As long as all the variables above are only written during the initialization,
>> this change is meant to prevent the false sharing and improve the
>> performance on large multiprocessor systems.
>>
>> Signed-off-by: Vlad Zolotarov<vlad@scalemp.com>
>> Signed-off-by: Shai Fultheim<shai@scalemp.com>
>> ---
>>   arch/x86/include/asm/apic.h    |    2 +-
>>   arch/x86/include/asm/smp.h     |   16 ++++++++--------
>>   arch/x86/kernel/apic/apic.c    |    6 +++---
>>   arch/x86/kernel/setup_percpu.c |    2 +-
>>   arch/x86/kernel/smpboot.c      |    8 ++++----
>>   5 files changed, 17 insertions(+), 17 deletions(-)
>
> This does not build on !SMP kernels that has APIC enabled.

Oops... :) My bad. I'll rebase and respin.

Thanks,
vlad

>
> Thanks,
>
> 	Ingo
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
>