linux-kernel - [PATCH v3 5/8] sched/topology: Remove redundant dl_clear_root

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Message-ID: <Z86y_ebAmhSaND09@jlelli-thinkpadt14gen4.remote.csb>
Date: Mon, 10 Mar 2025 10:38:05 +0100
From: Juri Lelli <juri.lelli@...hat.com>
To: linux-kernel@...r.kernel.org, cgroups@...r.kernel.org
Cc: Ingo Molnar <mingo@...hat.com>, Peter Zijlstra <peterz@...radead.org>,
	Vincent Guittot <vincent.guittot@...aro.org>,
	Dietmar Eggemann <dietmar.eggemann@....com>,
	Steven Rostedt <rostedt@...dmis.org>,
	Ben Segall <bsegall@...gle.com>, Mel Gorman <mgorman@...e.de>,
	Valentin Schneider <vschneid@...hat.com>,
	Waiman Long <longman@...hat.com>, Tejun Heo <tj@...nel.org>,
	Johannes Weiner <hannes@...xchg.org>,
	Michal Koutný <mkoutny@...e.com>,
	Qais Yousef <qyousef@...alina.io>,
	Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
	Swapnil Sapkal <swapnil.sapkal@....com>,
	Shrikanth Hegde <sshegde@...ux.ibm.com>,
	Phil Auld <pauld@...hat.com>, luca.abeni@...tannapisa.it,
	tommaso.cucinotta@...tannapisa.it,
	Jon Hunter <jonathanh@...dia.com>
Subject: [PATCH v3 5/8] sched/topology: Remove redundant dl_clear_root_domain
 call

We completely clean and restore root domains bandwidth accounting after
every root domains change, so the dl_clear_root_domain() call in
partition_sched_domains_locked() is redundant.

Remove it.

Reviewed-by: Waiman Long <llong@...hat.com>
Reviewed-by: Shrikanth Hegde <sshegde@...ux.ibm.com>
Tested-by: Waiman Long <longman@...hat.com>
Tested-by: Jon Hunter <jonathanh@...dia.com>
Signed-off-by: Juri Lelli <juri.lelli@...hat.com>
---
 kernel/sched/topology.c | 15 +--------------
 1 file changed, 1 insertion(+), 14 deletions(-)

diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 363ad268a25b..df2d94a57e84 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -2720,21 +2720,8 @@ void partition_sched_domains_locked(int ndoms_new, cpumask_var_t doms_new[],
 	for (i = 0; i < ndoms_cur; i++) {
 		for (j = 0; j < n && !new_topology; j++) {
 			if (cpumask_equal(doms_cur[i], doms_new[j]) &&
-			    dattrs_equal(dattr_cur, i, dattr_new, j)) {
-				struct root_domain *rd;
-
-				/*
-				 * This domain won't be destroyed and as such
-				 * its dl_bw->total_bw needs to be cleared.
-				 * Tasks contribution will be then recomputed
-				 * in function dl_update_tasks_root_domain(),
-				 * dl_servers contribution in function
-				 * dl_restore_server_root_domain().
-				 */
-				rd = cpu_rq(cpumask_any(doms_cur[i]))->rd;
-				dl_clear_root_domain(rd);
+			    dattrs_equal(dattr_cur, i, dattr_new, j))
 				goto match1;
-			}
 		}
 		/* No match - a current sched domain not in new doms_new[] */
 		detach_destroy_domains(doms_cur[i]);
-- 
2.48.1