Re: [PATCH v2 10/15] crypto: iaa - Add per-cpu workqueue table with rebalancing
From: Tom Zanussi
Date: Wed Mar 29 2023 - 10:58:54 EST
Hi Hillf,
On Wed, 2023-03-29 at 15:51 +0800, Hillf Danton wrote:
> On 28 Mar 2023 10:35:30 -0500 Tom Zanussi
> <tom.zanussi@xxxxxxxxxxxxxxx>
> > +/*
> > + * Given a cpu, find the closest IAA instance. The idea is to try
> > to
> > + * choose the most appropriate IAA instance for a caller and
> > spread
> > + * available workqueues around to clients.
> > + */
> > +static inline int cpu_to_iaa(int cpu)
> > +{
> > + int node, n_cpus = 0, test_cpu, iaa = 0;
> > + int nr_iaa_per_node, nr_cores_per_iaa;
> > + const struct cpumask *node_cpus;
> > +
> > + if (!nr_nodes)
> > + return 0;
> > +
> > + nr_iaa_per_node = nr_iaa / nr_nodes;
> > + if (!nr_iaa_per_node)
> > + return 0;
> > +
> > + nr_cores_per_iaa = nr_cpus_per_node / nr_iaa_per_node;
> > +
> > + for_each_online_node(node) {
> > + node_cpus = cpumask_of_node(node);
> > + if (!cpumask_test_cpu(cpu, node_cpus))
> > + continue;
>
> cpu_to_node(cpu) works for you.
Yes, thanks for pointing that out.
> > +
> > + for_each_cpu(test_cpu, node_cpus) {
> > + if ((n_cpus % nr_cpus_per_node) == 0)
> > + iaa = node * nr_iaa_per_node;
> > +
> > + if (test_cpu == cpu)
> > + return iaa;
>
> Given nr_iaa_per_node, why round robin-ing every iaa in the node not
> work?
True, we should be able to simplify this, will do for the next version.
Thanks,
Tom
> > +
> > + n_cpus++;
> > +
> > + if ((n_cpus % cpus_per_iaa) == 0)
> > + iaa++;
> > + }
> > + }
> > +
> > + return -1;
> > +}