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[141.239.159.203]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-1fa37e4b5b9sm27308625ad.260.2024.06.24.13.51.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Jun 2024 13:51:51 -0700 (PDT) Sender: Tejun Heo Date: Mon, 24 Jun 2024 10:51:49 -1000 From: Tejun Heo To: Peter Zijlstra Cc: Thomas Gleixner , Linus Torvalds , mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@kernel.org, joshdon@google.com, brho@google.com, pjt@google.com, derkling@google.com, haoluo@google.com, dvernet@meta.com, dschatzberg@meta.com, dskarlat@cs.cmu.edu, riel@surriel.com, changwoo@igalia.com, himadrics@inria.fr, memxor@gmail.com, andrea.righi@canonical.com, joel@joelfernandes.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kernel-team@meta.com Subject: [PATCH sched_ext/for-6.11] sched, sched_ext: Simplify dl_prio() case handling in sched_fork() Message-ID: References: <871q4rpi2s.ffs@tglx> <20240624093426.GH31592@noisy.programming.kicks-ass.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Tejun Heo sched_fork() returns with -EAGAIN if dl_prio(@p). a7a9fc549293 ("sched_ext: Add boilerplate for extensible scheduler class") added scx_pre_fork() call before it and then scx_cancel_fork() on the exit path. This is silly as the dl_prio() block can just be moved above the scx_pre_fork() call. Move the dl_prio() block above the scx_pre_fork() call and remove the now unnecessary scx_cancel_fork() invocation. Signed-off-by: Tejun Heo Suggested-by: Thomas Gleixner Cc: Ingo Molnar Cc: Peter Zijlstra Cc: David Vernet --- Hello, As this is pretty trivial, if no one objects, I'll apply this to sched_ext/for-6.11 after a bit. Thanks. kernel/sched/core.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4583,8 +4583,6 @@ late_initcall(sched_core_sysctl_init); */ int sched_fork(unsigned long clone_flags, struct task_struct *p) { - int ret; - __sched_fork(clone_flags, p); /* * We mark the process as NEW here. This guarantees that @@ -4621,12 +4619,12 @@ int sched_fork(unsigned long clone_flags p->sched_reset_on_fork =3D 0; } =20 + if (dl_prio(p->prio)) + return -EAGAIN; + scx_pre_fork(p); =20 - if (dl_prio(p->prio)) { - ret =3D -EAGAIN; - goto out_cancel; - } else if (rt_prio(p->prio)) { + if (rt_prio(p->prio)) { p->sched_class =3D &rt_sched_class; #ifdef CONFIG_SCHED_CLASS_EXT } else if (task_should_scx(p)) { @@ -4652,10 +4650,6 @@ int sched_fork(unsigned long clone_flags RB_CLEAR_NODE(&p->pushable_dl_tasks); #endif return 0; - -out_cancel: - scx_cancel_fork(p); - return ret; } =20 int sched_cgroup_fork(struct task_struct *p, struct kernel_clone_args *kar= gs)