linux-kernel - [PATCH] sched_ext: Fix incorrect use of bitwise AND

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Message-ID: <20241108195144.55747-1-arighi@nvidia.com>
Date: Fri,  8 Nov 2024 20:51:44 +0100
From: Andrea Righi <arighi@...dia.com>
To: Tejun Heo <tj@...nel.org>,
	David Vernet <void@...ifault.com>
Cc: Nathan Chancellor <nathan@...nel.org>,
	linux-kernel@...r.kernel.org
Subject: [PATCH] sched_ext: Fix incorrect use of bitwise AND

There is no reason to use a bitwise AND when checking the conditions to
enable NUMA optimization for the built-in CPU idle selection policy, so
use a logical AND instead.

Fixes: f6ce6b949304 ("sched_ext: Do not enable LLC/NUMA optimizations when domains overlap")
Reported-by: Nathan Chancellor <nathan@...nel.org>
Closes: https://lore.kernel.org/lkml/20241108181753.GA2681424@thelio-3990X/
Signed-off-by: Andrea Righi <arighi@...dia.com>
---
 kernel/sched/ext.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index f154aaeb69e4..012a7fc77263 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -3221,7 +3221,7 @@ static void update_selcpu_topology(void)
 	 * for an idle CPU in the same domain twice is redundant.
 	 */
 	cpus = cpumask_of_node(cpu_to_node(cpu));
-	if ((cpumask_weight(cpus) < num_online_cpus()) & llc_numa_mismatch())
+	if ((cpumask_weight(cpus) < num_online_cpus()) && llc_numa_mismatch())
 		enable_numa = true;
 	rcu_read_unlock();
 
-- 
2.47.0