Re: [RFC V2 05/12] cpuset: Add cpuset_inc() inside cpuset_init()

[Anshuman Khandual]

On 01/31/2017 08:06 PM, Vlastimil Babka wrote:
> On 01/30/2017 09:30 PM, Mel Gorman wrote:
>> On Mon, Jan 30, 2017 at 09:05:46AM +0530, Anshuman Khandual wrote:
>>> Currently cpusets_enabled() wrongfully returns 0 even if we have a root
>>> cpuset configured on the system. This got missed when jump level was
>>> introduced in place of number_of_cpusets with the commit 664eeddeef65
>>> ("mm: page_alloc: use jump labels to avoid checking number_of_cpusets")
>>> . This fixes the problem so that cpusets_enabled() returns positive even
>>> for the root cpuset.
>>>
>>> Fixes: 664eeddeef65 ("mm: page_alloc: use jump labels to avoid")
>>> Signed-off-by: Anshuman Khandual <khandual@xxxxxxxxxxxxxxxxxx>
>>
>> Superficially, this appears to always activate the cpuset_enabled
>> branch() when it doesn't really make sense that the root cpuset be
>> restricted.
> 
> Yes that's why root cpuset doesn't "count", as it's not supposed to be
> restricted (it's also documented in cpusets.txt) Thus the "Fixes:" tag
> is very misleading.

Agreed, I have removed the "Fixes: " tag in the proposed RFC already
posted on this thread where it puts it as a new enablement instead
and an addition to the capability what we already have with cpuset.
It will be great if you can please take a look and provide feedback.