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Subject: Re: [PATCH v4 03/10] sched/topology: Provide cfs_overload_cpus bitmap
To:     Steven Sistare <steven.sistare@oracle.com>, mingo@redhat.com,
        peterz@infradead.org
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        linux-kernel@vger.kernel.org
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From:   Valentin Schneider <valentin.schneider@arm.com>
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Date:   Sat, 8 Dec 2018 18:33:19 +0000
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On 07/12/2018 22:35, Steven Sistare wrote:
[...]
>>> +	if (!sds->cfs_overload_cpus) {
>>> +		mask = sparsemask_alloc_node(nr_cpu_ids, 3, flags, nid);
>>                                              ^^^^^^^^^^ ^^^
>>                                                  (1)    (2)
>>
>> (1): Is this necessary? Wouldn't cpumask_weight(span) suffice?
> 
> weight does not work because the ids are not consecutive.  As a future 
> optimization I have a patch that computes a local CPU id within the LLC
> and uses that as the bitmap index, and that uses weight.  For this first
> series I am keeping things simple.
> 

Oh, duh, non-contiguous spans strike again. Fair enough!

[...]