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SubjectRe: [PATCH] arm64: smp: Update the topology masks before calling CPU_STARTING notifiers
On 8/15/2014 3:43 AM, Will Deacon wrote:
> On Wed, Aug 13, 2014 at 02:11:09AM +0100, Rohit Vaswani wrote:
>> Currently, the CPU_STARTING notifiers would observe an incorrect sibling
>> mask since the notifier chain is called before the topology masks are updated
>> for the new cpu.
>> Update the topology masks before calling the notifier chain to fix this
>> problem.
>>
>> Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>
>> ---
>> arch/arm/kernel/smp.c | 4 ++--
>> arch/arm64/kernel/smp.c | 4 ++--
>> 2 files changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
>> index 7c4fada..0e2237c 100644
>> --- a/arch/arm/kernel/smp.c
>> +++ b/arch/arm/kernel/smp.c
>> @@ -363,12 +363,12 @@ asmlinkage void secondary_start_kernel(void)
>> if (smp_ops.smp_secondary_init)
>> smp_ops.smp_secondary_init(cpu);
>>
>> + smp_store_cpu_info(cpu);
>> +
>> notify_cpu_starting(cpu);
>>
>> calibrate_delay();
>>
>> - smp_store_cpu_info(cpu);
>> -
> Hmm, smp_store_cpu_info takes a copy of loops_per_jiffy. Are you sure it's
> safe to move the call before calibrate_delay?

Right! - I had looked at the arm64 version . I checked for arm32 now
and I think we should be
safe to move calibrate_delay before the smp_store_cpu_info and I can
push a v2 version if
there are no concerns. I did not see calibrate_delay having any
dependency for cpu_starting notifiers.

-Rohit
> Will


Thanks,
Rohit Vaswani

--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation



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