Re: [PATCH 06/13] irq: add a helper spread an affinity mask for MSI/MSI-X vectors
From: Bart Van Assche <hidden>
Date: 2016-06-15 08:50:47
Also in:
linux-nvme, linux-pci, lkml
On 06/14/2016 11:54 PM, Guilherme G. Piccoli wrote:
On 06/14/2016 04:58 PM, Christoph Hellwig wrote: I take this opportunity to ask you something, since I'm working in a related code in a specific driver - sorry in advance if my question is silly or if I misunderstood your code. The function irq_create_affinity_mask() below deals with the case in which we have nr_vecs < num_online_cpus(); in this case, wouldn't be a good idea to trying distribute the vecs among cores? Example: if we have 128 online cpus, 8 per core (meaning 16 cores) and 64 vecs, I guess would be ideal to distribute 4 vecs _per core_, leaving 4 CPUs in each core without vecs.
Hello Christoph and Guilherme, I would also like to see irq_create_affinity_mask() modified such that it implements Guilherme's algorithm. I think blk-mq requests should be processed by a CPU core from the NUMA node from which the request has been submitted. With the proposed algorithm, if the number of MSI-X vectors is less than or equal to the number of CPU cores of a single node, all interrupt vectors will be assigned to the first NUMA node. Bart. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme