From mboxrd@z Thu Jan 1 00:00:00 1970 From: keith.busch@intel.com (Keith Busch) Date: Mon, 22 Jan 2018 11:20:17 -0700 Subject: Why NVMe MSIx vectors affinity set across NUMA nodes? In-Reply-To: References: <20180122171437.GL12043@localhost.localdomain> <20180122173239.GM12043@localhost.localdomain> <20180122180515.GN12043@localhost.localdomain> Message-ID: <20180122182017.GO12043@localhost.localdomain> On Mon, Jan 22, 2018@11:42:45PM +0530, Ganapatrao Kulkarni wrote: > > AFAIK, usually drivers sets default affinity and it is likely be node > affinity for NUMA systems. > Later, it is the user-space(like irqbalance etc) which decides the > affinity not the driver. Relying on userspace to provide an optimal setting is a bad idea, especially for NVMe where we have submission queue cpu affinity that doesn't work very efficiently if the completion affinity doesn't match.