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[73.105.0.191]) by smtp.gmail.com with ESMTPSA id 00721157ae682-87149600f48sm114821757b3.13.2026.09.09.11.17.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Sep 2026 11:17:14 -0700 (PDT) From: Yury Norov X-Google-Original-From: Yury Norov To: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , K Prateek Nayak , linux-kernel@vger.kernel.org Cc: Yury Norov , Yury Norov Subject: [PATCH] sched/fair: Rework pick_task_fair() control flow Date: Wed, 9 Sep 2026 14:17:12 -0400 Message-ID: <20260909181712.1050224-1-ynorov@nvidia.com> X-Mailer: git-send-email 2.53.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Split out the logic picking a task from rq to a separate helper, and get rid of the gotos. With GCC 15.2.0 and x86_64_defconfig, the new version saves 96 bytes, and with defconfig + CONFIG_SCHED_CORE + CONFIG_CFS_BANDWIDTH it saves 124 bytes. No functional changes intended. Signed-off-by: Yury Norov --- kernel/sched/fair.c | 51 ++++++++++++++++++++++++--------------------- 1 file changed, 27 insertions(+), 24 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index ade1eceb39b8..ad0c477e58a8 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -10043,39 +10043,42 @@ static void wakeup_preempt_fair(struct rq *rq, struct task_struct *p, int wake_f resched_curr_lazy(rq); } -struct task_struct *pick_task_fair(struct rq *rq, struct rq_flags *rf) - __must_hold(__rq_lockp(rq)) +static struct task_struct *pick_task_fair_rq(struct rq *rq) { struct cfs_rq *cfs_rq = &rq->cfs; struct sched_entity *se; - struct task_struct *p; - int new_tasks; -again: - if (!cfs_rq->h_nr_queued) - goto idle; + while (cfs_rq->h_nr_queued) { + /* Might not have done put_prev_entity() */ + if (cfs_rq->curr && cfs_rq->curr->on_rq) + update_curr_eevdf(cfs_rq); - /* Might not have done put_prev_entity() */ - if (cfs_rq->curr && cfs_rq->curr->on_rq) - update_curr_eevdf(cfs_rq); + se = pick_next_entity(rq, true); + if (se) + return task_of(se); + } - se = pick_next_entity(rq, true); - if (!se) - goto again; + return NULL; +} - p = task_of(se); - return p; +struct task_struct *pick_task_fair(struct rq *rq, struct rq_flags *rf) + __must_hold(__rq_lockp(rq)) +{ + struct task_struct *p; + int new_tasks; -idle: - if (sched_core_enabled(rq)) - return NULL; + do { + p = pick_task_fair_rq(rq); + if (p) + return p; - new_tasks = sched_balance_newidle(rq, rf); - if (new_tasks < 0) - return RETRY_TASK; - if (new_tasks > 0) - goto again; - return NULL; + if (sched_core_enabled(rq)) + return NULL; + + new_tasks = sched_balance_newidle(rq, rf); + } while (new_tasks > 0); + + return new_tasks ? RETRY_TASK : NULL; } static struct task_struct * -- 2.53.0