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From: Waiman Long <longman@redhat.com>
To: "Ridong Chen" <ridong.chen@linux.dev>,
	"Tejun Heo" <tj@kernel.org>,
	"Johannes Weiner" <hannes@cmpxchg.org>,
	"Michal Koutný" <mkoutny@suse.com>,
	"Shuah Khan" <shuah@kernel.org>
Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-kselftest@vger.kernel.org,
	Guopeng Zhang <guopeng.zhang@linux.dev>,
	Waiman Long <longman@redhat.com>
Subject: [PATCH-next v2 10/10] cgroup/cpuset: Integrate compute_partition_effective_cpumask() into compute_effective_cpumask()
Date: Fri, 23 Oct 2026 16:00:36 -0400	[thread overview]
Message-ID: <20261023200036.60560-11-longman@redhat.com> (raw)
In-Reply-To: <20261023200036.60560-1-longman@redhat.com>

Update compute_effective_cpumask() to call
compute_partition_effective_cpumask() directly if the given cpuset is
a valid remote or local partition root. This simplifies the call sites
where they are being involved. No functional change is expected.

Suggested-by: Ridong Chen <ridong.chen@linux.dev>
Signed-off-by: Waiman Long <longman@redhat.com>
---
 kernel/cgroup/cpuset.c | 37 ++++++++++---------------------------
 1 file changed, 10 insertions(+), 27 deletions(-)

diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index f9ba711e1e1a..9190dc8e4c49 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -1567,8 +1567,6 @@ static void compute_partition_effective_cpumask(struct cpuset *cs,
 	struct cpuset *child;
 	bool populated = partition_is_populated(cs, NULL);
 
-	WARN_ON_ONCE(!is_partition_valid(cs));
-
 	/*
 	 * Check child partition roots to see if they should be invalidated
 	 * when all the effective_cpus will be used up and cs is populated.
@@ -1629,6 +1627,10 @@ static void compute_effective_cpumask(struct cpumask *new_cpus,
 {
 	bool has_cpus;
 
+	if (is_remote_partition(cs) ||
+	    (is_partition_valid(cs) && is_partition_valid(parent)))
+		return compute_partition_effective_cpumask(cs, new_cpus);
+
 	has_cpus = cpumask_and(new_cpus, cs->cpus_allowed, parent->effective_cpus);
 	if (!has_cpus && is_in_v2_mode())
 		cpumask_copy(new_cpus, parent->effective_cpus);
@@ -2224,10 +2226,7 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp,
 			remote = (new_prs == old_prs);
 		}
 
-		if (remote || (is_partition_valid(parent) && is_partition_valid(cp)))
-			compute_partition_effective_cpumask(cp, tmp->new_cpus);
-		else
-			compute_effective_cpumask(tmp->new_cpus, cp, parent);
+		compute_effective_cpumask(tmp->new_cpus, cp, parent);
 
 		if (remote)
 			goto get_css;	/* Ready to update cpuset data */
@@ -2326,10 +2325,7 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp,
 			 */
 			new_prs = cp->partition_root_state;
 			if (new_prs != old_prs) {
-				if (new_prs > 0)
-					compute_partition_effective_cpumask(cp, tmp->new_cpus);
-				else
-					compute_effective_cpumask(tmp->new_cpus, cp, parent);
+				compute_effective_cpumask(tmp->new_cpus, cp, parent);
 			}
 		}
 
@@ -3961,7 +3957,6 @@ static void cpuset_hotplug_update_tasks(struct cpuset *cs, struct tmpmasks *tmp)
 	static nodemask_t new_mems;
 	bool cpus_updated;
 	bool mems_updated;
-	bool remote;
 	int partcmd = -1;
 	struct cpuset *parent;
 
@@ -3973,21 +3968,12 @@ static void cpuset_hotplug_update_tasks(struct cpuset *cs, struct tmpmasks *tmp)
 	if (!tmp || !cs->partition_root_state)
 		goto update_tasks;
 
-	/*
-	 * Compute effective_cpus for valid partition root, may invalidate
-	 * child partition roots if necessary.
-	 */
-	remote = is_remote_partition(cs);
-	if (remote || (is_partition_valid(cs) && is_partition_valid(parent)))
-		compute_partition_effective_cpumask(cs, &new_cpus);
-
-	if (remote && (cpumask_empty(subpartitions_cpus) ||
-			(cpumask_empty(&new_cpus) &&
-			 partition_is_populated(cs, NULL)))) {
+	if (is_remote_partition(cs) && (cpumask_empty(subpartitions_cpus) ||
+				       (cpumask_empty(&new_cpus) &&
+					partition_is_populated(cs, NULL)))) {
 		WRITE_ONCE(cs->prs_err, PERR_HOTPLUG);
 		remote_partition_disable(cs, tmp);
 		compute_effective_cpumask(&new_cpus, cs, parent);
-		remote = false;
 	}
 
 	/*
@@ -4013,10 +3999,7 @@ static void cpuset_hotplug_update_tasks(struct cpuset *cs, struct tmpmasks *tmp)
 
 	if (partcmd >= 0) {
 		update_parent_effective_cpumask(cs, partcmd, NULL, tmp);
-		if (is_partition_valid(cs)) {
-			compute_partition_effective_cpumask(cs, &new_cpus);
-			cpuset_force_rebuild();
-		} else if (partcmd == partcmd_invalidate) {
+		if (is_partition_valid(cs) || (partcmd == partcmd_invalidate)) {
 			compute_effective_cpumask(&new_cpus, cs, parent);
 			cpuset_force_rebuild();
 		}
-- 
2.56.0


      parent reply	other threads:[~2026-10-23 20:01 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-10-23 20:00 [PATCH-next v2 00/10] cgroup/cpuset: Miscellaneous bug fixes & cleanup Waiman Long
2026-10-23 20:00 ` [PATCH-next v2 01/10] cgroup/cpuset: Find furthest isolated ancestor for invalidated isolated partition Waiman Long
2026-10-23 20:00 ` [PATCH-next v2 02/10] cgroup/cpuset: Properly compute effective xcpus in update_parent_effective_cpumask() Waiman Long
2026-10-23 20:00 ` [PATCH-next v2 03/10] cgroup/cpuset: Fix incorrect effective_cpus bug in update_cpumasks_hier() Waiman Long
2026-10-23 20:00 ` [PATCH-next v2 04/10] cgroup/cpuset: Minor fixes to prstate_housekeeping_conflict() Waiman Long
2026-10-23 20:00 ` [PATCH-next v2 05/10] selftests/cgroup: Check for a single range nohz_full CPUs before running test matrix Waiman Long
2026-10-23 20:00 ` [PATCH-next v2 06/10] cgroup/cpuset: Prevent recursive call of remote_cpus_update() via update_cpumasks_hier() Waiman Long
2026-10-23 20:00 ` [PATCH-next v2 07/10] cgroup/cpuset: Make sure compute_partition_effective_cpumask() is only called for valid partition Waiman Long
2026-10-23 20:00 ` [PATCH-next v2 08/10] cgroup/cpuset: Update isolated_cpus if necessary in compute_partition_effective_cpumask() Waiman Long
2026-10-23 20:00 ` [PATCH-next v2 09/10] cgroup/cpuset: Relocate compute_*effective_cpumask() and compute_effective_nodemask() Waiman Long
2026-10-23 20:00 ` Waiman Long [this message]

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