On Mon, Oct 07, 2019 at 11:23:22AM +0100, John Garry wrote:
> On 06/10/2019 03:45, Ming Lei wrote:
> > + }
> > +}
> > +
> > +static int blk_mq_hctx_notify_online(unsigned int cpu, struct hlist_node *node)
> > +{
> > + struct blk_mq_hw_ctx *hctx = hlist_entry_safe(node,
> > + struct blk_mq_hw_ctx, cpuhp_online);
> > + unsigned prev_cpu = -1;
> > +
> > + while (true) {
> > + unsigned next_cpu = cpumask_next_and(prev_cpu, hctx->cpumask,
> > + cpu_online_mask);
> > +
> > + if (next_cpu >= nr_cpu_ids)
> > + break;
> > +
> > + /* return if there is other online CPU on this hctx */
> > + if (next_cpu != cpu)
> > + return 0;
> > +
> > + prev_cpu = next_cpu;
> > + }
> > +
> > + set_bit(BLK_MQ_S_INTERNAL_STOPPED, &hctx->state);
> > + blk_mq_drain_inflight_rqs(hctx);
> > +
>
> Does this do the same:
>
> {
> struct blk_mq_hw_ctx *hctx = hlist_entry_safe(node,
> struct blk_mq_hw_ctx, cpuhp_online);
> cpumask_var_t tmp;
>
> cpumask_and(tmp, hctx->cpumask, cpu_online_mask);
>
> /* test if there is any other cpu online in the hctx cpu mask */
> if (cpumask_any_but(tmp, cpu) < nr_cpu_ids)
> return 0;
>
> set_bit(BLK_MQ_S_INTERNAL_STOPPED, &hctx->state);
> blk_mq_drain_inflight_rqs(hctx);
>
> return 0;
> }
>
> If so, it's more readable and concise.
Yes, but we have to allocate space for 'tmp', that is what this patch
tries to avoid, given the logic isn't too complicated.
>
>
> BTW, You could have added my Tested-by tags...
OK, I will add it in V3.
Thanks,
Ming
