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[72.235.129.167]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-7106ecdff69sm3344210b3a.118.2024.08.03.19.40.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 03 Aug 2024 19:40:54 -0700 (PDT) Sender: Tejun Heo From: Tejun Heo To: void@manifault.com, peterz@infradead.org Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, mingo@redhat.com, Tejun Heo Subject: [PATCH 2/6] sched_ext: Add scx_enabled() test to @start_class promotion in put_prev_task_balance() Date: Sat, 3 Aug 2024 16:40:09 -1000 Message-ID: <20240804024047.100355-3-tj@kernel.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240804024047.100355-1-tj@kernel.org> References: <20240804024047.100355-1-tj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit SCX needs its balance() invoked even when waking up from a lower priority sched class (idle) and put_prev_task_balance() thus has the logic to promote @start_class if it's lower than ext_sched_class. This is only needed when SCX is enabled. Add scx_enabled() test to avoid unnecessary overhead when SCX is disabled. Signed-off-by: Tejun Heo Suggested-by: Peter Zijlstra --- kernel/sched/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 7994118eee53..0532b27fd9af 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5836,7 +5836,7 @@ static void put_prev_task_balance(struct rq *rq, struct task_struct *prev, * when waking up from SCHED_IDLE. If @start_class is below SCX, start * from SCX instead. */ - if (sched_class_above(&ext_sched_class, start_class)) + if (scx_enabled() && sched_class_above(&ext_sched_class, start_class)) start_class = &ext_sched_class; #endif -- 2.46.0