From mboxrd@z Thu Jan 1 00:00:00 1970 From: ming.lei@redhat.com (Ming Lei) Date: Tue, 25 Jun 2019 10:14:12 +0800 Subject: [PATCH v3 4/5] genirq/affinity: allow driver's discontigous affinity set In-Reply-To: References: <1ead341c6d603cf138aed62e31091f257cb19981.1561385989.git.zhangweiping@didiglobal.com> Message-ID: <20190625021411.GD23777@ming.t460p> Hi Thomas, On Mon, Jun 24, 2019@05:42:39PM +0200, Thomas Gleixner wrote: > On Mon, 24 Jun 2019, Weiping Zhang wrote: > > > The driver may implement multiple affinity set, and some of > > are empty, for this case we just skip them. > > Why? What's the point of creating empty sets? Just because is not a real > good justification. Patch 5 will add 4 new sets for supporting NVMe's weighted round robin arbitration. It can be a headache to manage so many irq sets(now the total sets can become 6) dynamically since size of anyone in the new 4 sets can be zero, so each particular set is assigned one static index for avoiding the management trouble, then empty set will be seen by irq_create_affinity_masks(). So looks skipping the empty set makes sense because the API will become easier to use than before. Thanks, Ming