On 03/17/2016 05:01 AM, Thomas Gleixner wrote:
> On Thu, 17 Mar 2016, Peter Zijlstra wrote:
>> On Thu, Mar 17, 2016 at 12:39:46PM +0100, Thomas Gleixner wrote:
>>> But we have to clarify and document whether holes in cpu_possible_mask are not
>>> allowed at all or if code like the above is simply broken.
>>
>> So the general rule is that cpumasks can have holes, and exempting one
>> just muddles the water.
>>
>> Therefore I'd call the code just plain broken.
>
> Agreed.
>
> That macro is not really helping the readability of the code at all. So a
> simple for_each_possible_cpu() loop would have avoided that wreckage.

Does the attached work? The rest of blk-mq should deal with holes just 
fine, we found some of those issues on sparc. Not sure why this one 
slipped through the cracks.

-- 
Jens Axboe