Re: [PATCH v3 3/8] sched/topology: Switch to assigning "sd->shared" from s_data

[K Prateek Nayak <kprateek.nayak@amd.com>]

Hello Shrikanth,

On 1/22/2026 1:42 PM, Shrikanth Hegde wrote:
>> @@ -2709,6 +2720,9 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att
>>           if (!cpumask_test_cpu(i, cpu_map))
>>               continue;
>>   +        if (atomic_read(&(*per_cpu_ptr(d.sds, i))->ref))
>> +            *per_cpu_ptr(d.sds, i) = NULL;
>> +
> 
> Can we do this claim_allocations only?

I didn't do it there since we didn't have reference to the "s_data"
inside claim_allocations().

If I remember this right, only init_sched_groups_capacity() has the
requirement to traverse the CPUs in reverse to do
update_group_capacity() when we hit the first CPU in the group.
It doesn't modify the "->ref" of any allocations.

I can put the claim_allocations() bits the previous loop and pass the
CPU and the s_data reference so it can free both "d.sds" and all the
"d.sd" bits in one place and retain this reverse loop for
init_sched_groups_capacity(). Does that sound better?

> sdt_alloc and free is complicated already.
> 
>>           for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) {
>>               claim_allocations(i, sd);
>>               init_sched_groups_capacity(i, sd);
> 

-- 
Thanks and Regards,
Prateek