From: Tejun Heo <tj@kernel.org>
Date: Mon, 22 Sep 2025 01:32:40 +0000 (-1000)
Subject: sched_ext: Use rhashtable_lookup() instead of rhashtable_lookup_fast()
X-Git-Tag: v6.19-rc1~177^2~31
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e67708823d7362cfbb557008563cce7e7c9c5128;p=thirdparty%2Fkernel%2Flinux.git

sched_ext: Use rhashtable_lookup() instead of rhashtable_lookup_fast()

The find_user_dsq() function is called from contexts that are already
under RCU read lock protection. Switch from rhashtable_lookup_fast() to
rhashtable_lookup() to avoid redundant RCU locking.

Requires: bee8a520eb84 ("rhashtable: Use rcu_dereference_all and rcu_dereference_all_check")
Acked-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---

diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index 04079ae4246e3..bde49e47f1e4b 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -200,7 +200,7 @@ static struct scx_dispatch_q *find_global_dsq(struct scx_sched *sch,
 
 static struct scx_dispatch_q *find_user_dsq(struct scx_sched *sch, u64 dsq_id)
 {
-	return rhashtable_lookup_fast(&sch->dsq_hash, &dsq_id, dsq_hash_params);
+	return rhashtable_lookup(&sch->dsq_hash, &dsq_id, dsq_hash_params);
 }
 
 /*