linux-kernel - [PATCH 1/4] net: mellanox: drop mlx5_cpumask_default

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Message-Id: <20230925020528.777578-2-yury.norov@gmail.com>
Date:   Sun, 24 Sep 2023 19:05:25 -0700
From:   Yury Norov <yury.norov@...il.com>
To:     linux-kernel@...r.kernel.org, netdev@...r.kernel.org,
        linux-rdma@...r.kernel.org
Cc:     Yury Norov <yury.norov@...il.com>,
        Tariq Toukan <ttoukan.linux@...il.com>,
        Valentin Schneider <vschneid@...hat.com>,
        Maher Sanalla <msanalla@...dia.com>,
        Ingo Molnar <mingo@...nel.org>, Mel Gorman <mgorman@...e.de>,
        Saeed Mahameed <saeedm@...dia.com>,
        Leon Romanovsky <leon@...nel.org>,
        "David S. Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Juri Lelli <juri.lelli@...hat.com>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Ben Segall <bsegall@...gle.com>,
        Daniel Bristot de Oliveira <bristot@...hat.com>,
        Pawel Chmielewski <pawel.chmielewski@...el.com>,
        Jacob Keller <jacob.e.keller@...el.com>,
        Yury Norov <ynorov@...dia.com>
Subject: [PATCH 1/4] net: mellanox: drop mlx5_cpumask_default_spread()

The function duplicates existing cpumask_local_spread(), and it's O(N),
while cpumask_local_spread() implementation is based on bsearch, and
thus is O(log n), so drop mlx5_cpumask_default_spread() and use generic
cpumask_local_spread().

Signed-off-by: Yury Norov <yury.norov@...il.com>
Signed-off-by: Yury Norov <ynorov@...dia.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/eq.c | 28 ++------------------
 1 file changed, 2 insertions(+), 26 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eq.c b/drivers/net/ethernet/mellanox/mlx5/core/eq.c
index ea0405e0a43f..bd9f857cc52d 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/eq.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eq.c
@@ -828,30 +828,6 @@ static void comp_irq_release_pci(struct mlx5_core_dev *dev, u16 vecidx)
 	mlx5_irq_release_vector(irq);
 }
 
-static int mlx5_cpumask_default_spread(int numa_node, int index)
-{
-	const struct cpumask *prev = cpu_none_mask;
-	const struct cpumask *mask;
-	int found_cpu = 0;
-	int i = 0;
-	int cpu;
-
-	rcu_read_lock();
-	for_each_numa_hop_mask(mask, numa_node) {
-		for_each_cpu_andnot(cpu, mask, prev) {
-			if (i++ == index) {
-				found_cpu = cpu;
-				goto spread_done;
-			}
-		}
-		prev = mask;
-	}
-
-spread_done:
-	rcu_read_unlock();
-	return found_cpu;
-}
-
 static struct cpu_rmap *mlx5_eq_table_get_pci_rmap(struct mlx5_core_dev *dev)
 {
 #ifdef CONFIG_RFS_ACCEL
@@ -873,7 +849,7 @@ static int comp_irq_request_pci(struct mlx5_core_dev *dev, u16 vecidx)
 	int cpu;
 
 	rmap = mlx5_eq_table_get_pci_rmap(dev);
-	cpu = mlx5_cpumask_default_spread(dev->priv.numa_node, vecidx);
+	cpu = cpumask_local_spread(vecidx, dev->priv.numa_node);
 	irq = mlx5_irq_request_vector(dev, cpu, vecidx, &rmap);
 	if (IS_ERR(irq))
 		return PTR_ERR(irq);
@@ -1125,7 +1101,7 @@ int mlx5_comp_vector_get_cpu(struct mlx5_core_dev *dev, int vector)
 	if (mask)
 		cpu = cpumask_first(mask);
 	else
-		cpu = mlx5_cpumask_default_spread(dev->priv.numa_node, vector);
+		cpu = cpumask_local_spread(vector, dev->priv.numa_node);
 
 	return cpu;
 }
-- 
2.39.2