On Mon, Feb 03, 2020 at 06:28:15PM +0800, Hillf Danton wrote: > > Hi Ming > > On Mon, 3 Feb 2020 17:16:02 +0800 Ming Lei wrote: > > On Sun, Feb 02, 2020 at 06:20:04PM +0800, Hillf Danton wrote: > > > > > > Select the current cpu if it's mapped to hardware to make helpers like > > > blk_mq_rq_cpu() return correct value. > > > > > > Signed-off-by: Hillf Danton <hdanton@xxxxxxxx> > > > --- > > > > > > --- a/block/blk-mq.c > > > +++ b/block/blk-mq.c > > > @@ -454,7 +454,10 @@ struct request *blk_mq_alloc_request_hct > > > blk_queue_exit(q); > > > return ERR_PTR(-EXDEV); > > > } > > > - cpu = cpumask_first_and(alloc_data.hctx->cpumask, cpu_online_mask); > > > + cpu = raw_smp_processor_id(); > > > + if (!cpumask_test_cpu(cpu, alloc_data.hctx->cpumask)) > > > + cpu = cpumask_first_and(alloc_data.hctx->cpumask, > > > + cpu_online_mask); > > > > How can you know if there is any online CPU available for this hctx? > > I don't except for the current cpu. The current CPU may not belong to hctx->cpumask for blk_mq_alloc_request_hctx(), that is why I think this API is very weird. Thanks, Ming
