Re: [PATCH 2/2] net/mlx5e: Leverage sched_numa_hop_mask()
From: Tariq Toukan <hidden>
Date: 2022-08-10 12:58:32
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On 8/10/2022 1:51 PM, Valentin Schneider wrote:
Signed-off-by: Valentin Schneider <vschneid@redhat.com> --- drivers/net/ethernet/mellanox/mlx5/core/eq.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)
Missing description. I had a very detailed description with performance numbers and an affinity hints example with before/after tables. I don't want to get them lost.
quoted hunk ↗ jump to hunk
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eq.c b/drivers/net/ethernet/mellanox/mlx5/core/eq.c index 229728c80233..2eb4ffd96a95 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/eq.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/eq.c@@ -809,9 +809,12 @@ static void comp_irqs_release(struct mlx5_core_dev *dev) static int comp_irqs_request(struct mlx5_core_dev *dev) { struct mlx5_eq_table *table = dev->priv.eq_table; + const struct cpumask *mask; int ncomp_eqs = table->num_comp_eqs; + int hops = 0; u16 *cpus; int ret; + int cpu; int i; ncomp_eqs = table->num_comp_eqs;@@ -830,8 +833,17 @@ static int comp_irqs_request(struct mlx5_core_dev *dev) ret = -ENOMEM; goto free_irqs; } - for (i = 0; i < ncomp_eqs; i++) - cpus[i] = cpumask_local_spread(i, dev->priv.numa_node); + + rcu_read_lock(); + for_each_numa_hop_mask(dev->priv.numa_node, hops, mask) {
We don't really use this 'hops' iterator. We always pass 0 (not a valuable input...), and we do not care about its final value. Probably it's best to hide it from the user into the macro.
+ for_each_cpu(cpu, mask) {
+ cpus[i] = cpu;
+ if (++i == ncomp_eqs)
+ goto spread_done;
+ }
+ }
+spread_done:
+ rcu_read_unlock();
ret = mlx5_irqs_request_vectors(dev, cpus, ncomp_eqs, table->comp_irqs);
kfree(cpus);
if (ret < 0)This logic is typical. Other drivers would also want to use it. It must be introduced as a service/API function, if not by the sched topology, then at least by the networking subsystem. Jakub, WDYT?