On 2020-05-20 19:57, Ming Lei wrote: > On Wed, May 20, 2020 at 02:46:52PM -0700, Bart Van Assche wrote: >> If the CPU to which one of these interrupt vectors has >> been assigned is hotplugged, does that mean that four hardware queues >> have to be quiesced instead of only one as is done in patch 6/6? > > No, one hctx only becomes inactive after each CPU in hctx->cpumask is offline. > No matter how interrupt vector is assigned to hctx, requests shouldn't > be dispatched to that hctx any more. Since I haven't found an answer to my question in your reply I will rephrase my question. Suppose that there are 16 CPU cores, 16 hardware queues and that hctx->cpumask of each hardware queue i only contains CPU i. Suppose that four interrupt vectors (0, 1, 2 and 3) are used to report the completions for these hardware queues. Suppose that interrupt vector 3 is associated with hardware queues 12, 13, 14 and 15, and also that interrupt vector 3 is mapped to CPU core 14. My interpretation of patch 6/6 is that it will only quiesce hardware queue 14 but none of the other hardware queues associated with the same interrupt vector (hardware queues 12, 13 and 15). Isn't that a bug? Thanks, Bart.
