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Sender: Tejun Heo <htejun@gmail.com>
From: Tejun Heo <tj@kernel.org>
To: jiangshanlai@gmail.com
Cc: linux-kernel@vger.kernel.org,
	Naohiro.Aota@wdc.com,
	kernel-team@meta.com,
	Tejun Heo <tj@kernel.org>
Subject: [PATCH 06/10] workqueue: Add first_possible_node and node_nr_cpus[]
Date: Wed, 20 Dec 2023 16:24:37 +0900
Message-ID: <20231220072529.1036099-7-tj@kernel.org>
In-Reply-To: <20231220072529.1036099-1-tj@kernel.org>
References: <20231220072529.1036099-1-tj@kernel.org>
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To track the first possible NUMA node and the number of online CPUs in each
NUMA node, respectively. These will be used to implement system-wide
nr_active for unbound workqueues.

Signed-off-by: Tejun Heo <tj@kernel.org>
---
 kernel/workqueue.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 143c0b31505e..a9f63cd61454 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -53,6 +53,7 @@
 #include <linux/nmi.h>
 #include <linux/kvm_para.h>
 #include <linux/delay.h>
+#include <linux/topology.h>
 
 #include "workqueue_internal.h"
 
@@ -338,6 +339,8 @@ struct wq_pod_type {
 	int			*cpu_pod;	/* cpu -> pod */
 };
 
+static int first_possible_node __read_mostly;
+static int node_nr_cpus[MAX_NUMNODES] __read_mostly;
 static struct wq_pod_type wq_pod_types[WQ_AFFN_NR_TYPES];
 static enum wq_affn_scope wq_affn_dfl = WQ_AFFN_CACHE;
 
@@ -5610,6 +5613,8 @@ int workqueue_online_cpu(unsigned int cpu)
 	struct workqueue_struct *wq;
 	int pi;
 
+	node_nr_cpus[cpu_to_node(cpu)]++;
+
 	mutex_lock(&wq_pool_mutex);
 
 	for_each_pool(pool, pi) {
@@ -5665,6 +5670,8 @@ int workqueue_offline_cpu(unsigned int cpu)
 	}
 	mutex_unlock(&wq_pool_mutex);
 
+	node_nr_cpus[cpu_to_node(cpu)]--;
+
 	return 0;
 }
 
@@ -6601,6 +6608,9 @@ void __init workqueue_init_early(void)
 
 	BUILD_BUG_ON(__alignof__(struct pool_workqueue) < __alignof__(long long));
 
+	first_possible_node = first_node(node_states[N_POSSIBLE]);
+	node_nr_cpus[cpu_to_node(0)]++;
+
 	BUG_ON(!alloc_cpumask_var(&wq_unbound_cpumask, GFP_KERNEL));
 	cpumask_copy(wq_unbound_cpumask, cpu_possible_mask);
 	restrict_unbound_cpumask("HK_TYPE_WQ", housekeeping_cpumask(HK_TYPE_WQ));
-- 
2.43.0