Re: [PATCH V6 0/2] genriq/affinity: Make vectors allocation fair

[Ming Lei]

On Mon, Aug 19, 2019 at 08:49:35PM +0800, Ming Lei wrote:
> Hi Thomas,
> 
> The 1st patch makes __irq_build_affinity_masks() more reliable, such as,
> all nodes can be covered in the spread.
> 
> The 2nd patch spread vectors on node according to the ratio of this node's
> CPU number to number of all remaining CPUs, then vectors assignment can
> become more fair. Meantime, the warning report from Jon Derrick can be
> fixed.
> 
> Please consider it for V5.4.
> 
> V6:
> 	- fix build waring reported by zero day, and extra change is only
> 	done on irq_build_affinity_masks()
> 
> V5:
> 	- remove patch 1 of V4, which is wrong
> 	- handle vector wrapping because the 'start vector' may begin
> 	  anywhere, especially for the 2nd stage spread
> 	- add more comment on the vector allocation algorithm
> 	- cleanup code a bit
> 	- run more tests to verify the change, which always get the
> 	expected result. Covers lots of num_queues, numa topo, CPU
> 	unpresent setting.
> 
> V4:
> 	- provide proof why number of allocated vectors for each node is <= CPU
> 	  count of this node
> 
> V3:
> 	- re-order the patchset
> 	- add helper of irq_spread_vectors_on_node()
> 	- handle vector spread correctly in case that numvecs is > ncpus
> 	- return -ENOMEM to API's caller
> 
> V2:
> 	- add patch3
> 	- start to allocate vectors from node with minimized CPU number,
> 	  then every node is guaranteed to be allocated at least one vector.
> 	- avoid cross node spread
> 
> 
> 
> Ming Lei (2):
>   genirq/affinity: Improve __irq_build_affinity_masks()
>   genirq/affinity: Spread vectors on node according to nr_cpu ratio
> 
>  kernel/irq/affinity.c | 231 ++++++++++++++++++++++++++++++++++++------
>  1 file changed, 201 insertions(+), 30 deletions(-)
> 
> Cc: Jens Axboe <axboe@xxxxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Keith Busch <kbusch@xxxxxxxxxx>
> Cc: linux-nvme@xxxxxxxxxxxxxxxxxxx,
> Cc: Jon Derrick <jonathan.derrick@xxxxxxxxx>
> -- 
> 2.20.1
> 

Hi Thomas,

Gentle ping on the two patches.


Thanks, 
Ming