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From:   Aaron Lu <aaron.lu@intel.com>
To:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Juri Lelli <juri.lelli@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Daniel Jordan <daniel.m.jordan@oracle.com>
Cc:     Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
        Daniel Bristot de Oliveira <bristot@redhat.com>,
        Valentin Schneider <vschneid@redhat.com>,
        Tim Chen <tim.c.chen@intel.com>,
        Nitin Tekchandani <nitin.tekchandani@intel.com>,
        Yu Chen <yu.c.chen@intel.com>,
        Waiman Long <longman@redhat.com>, linux-kernel@vger.kernel.org
Subject: [PATCH 1/4] sched/fair: free allocated memory on error in alloc_fair_sched_group()
Date:   Tue, 18 Jul 2023 21:41:17 +0800
Message-ID: <20230718134120.81199-2-aaron.lu@intel.com>
In-Reply-To: <20230718134120.81199-1-aaron.lu@intel.com>
References: <20230718134120.81199-1-aaron.lu@intel.com>
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There is one struct cfs_rq and one struct se on each cpu for a taskgroup
and when allocation for tg->cfs_rq[X] failed, the already allocated
tg->cfs_rq[0]..tg->cfs_rq[X-1] should be freed. The same for tg->se.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
---
 kernel/sched/fair.c | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index a80a73909dc2..0f913487928d 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -12443,10 +12443,10 @@ int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
 
 	tg->cfs_rq = kcalloc(nr_cpu_ids, sizeof(cfs_rq), GFP_KERNEL);
 	if (!tg->cfs_rq)
-		goto err;
+		return 0;
 	tg->se = kcalloc(nr_cpu_ids, sizeof(se), GFP_KERNEL);
 	if (!tg->se)
-		goto err;
+		goto err_free_rq_pointer;
 
 	tg->shares = NICE_0_LOAD;
 
@@ -12456,12 +12456,12 @@ int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
 		cfs_rq = kzalloc_node(sizeof(struct cfs_rq),
 				      GFP_KERNEL, cpu_to_node(i));
 		if (!cfs_rq)
-			goto err;
+			goto err_free;
 
 		se = kzalloc_node(sizeof(struct sched_entity_stats),
 				  GFP_KERNEL, cpu_to_node(i));
 		if (!se)
-			goto err_free_rq;
+			goto err_free;
 
 		init_cfs_rq(cfs_rq);
 		init_tg_cfs_entry(tg, cfs_rq, se, i, parent->se[i]);
@@ -12470,9 +12470,18 @@ int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
 
 	return 1;
 
-err_free_rq:
-	kfree(cfs_rq);
-err:
+err_free:
+	for_each_possible_cpu(i) {
+		kfree(tg->cfs_rq[i]);
+		kfree(tg->se[i]);
+
+		if (!tg->cfs_rq[i] && !tg->se[i])
+			break;
+	}
+	kfree(tg->se);
+err_free_rq_pointer:
+	kfree(tg->cfs_rq);
+
 	return 0;
 }
 
-- 
2.41.0