diff mbox series

[29/34] sched_ext: Implement sched_ext_ops.cpu_online/offline()

Message ID 20230711011412.100319-30-tj@kernel.org (mailing list archive)
State Not Applicable
Headers show
Series [01/34] cgroup: Implement cgroup_show_cftypes() | expand

Checks

Context Check Description
netdev/tree_selection success Not a local patch, async
bpf/vmtest-bpf-PR success PR summary
bpf/vmtest-bpf-VM_Test-1 success Logs for ShellCheck
bpf/vmtest-bpf-VM_Test-2 success Logs for build for aarch64 with gcc
bpf/vmtest-bpf-VM_Test-3 success Logs for build for s390x with gcc
bpf/vmtest-bpf-VM_Test-4 success Logs for build for x86_64 with gcc
bpf/vmtest-bpf-VM_Test-5 success Logs for build for x86_64 with llvm-16
bpf/vmtest-bpf-VM_Test-6 success Logs for set-matrix
bpf/vmtest-bpf-VM_Test-7 success Logs for test_maps on aarch64 with gcc
bpf/vmtest-bpf-VM_Test-8 pending Logs for test_maps on s390x with gcc
bpf/vmtest-bpf-VM_Test-9 success Logs for test_maps on x86_64 with gcc
bpf/vmtest-bpf-VM_Test-10 success Logs for test_maps on x86_64 with llvm-16
bpf/vmtest-bpf-VM_Test-11 success Logs for test_progs on aarch64 with gcc
bpf/vmtest-bpf-VM_Test-12 pending Logs for test_progs on s390x with gcc
bpf/vmtest-bpf-VM_Test-13 success Logs for test_progs on x86_64 with gcc
bpf/vmtest-bpf-VM_Test-14 success Logs for test_progs on x86_64 with llvm-16
bpf/vmtest-bpf-VM_Test-15 success Logs for test_progs_no_alu32 on aarch64 with gcc
bpf/vmtest-bpf-VM_Test-16 pending Logs for test_progs_no_alu32 on s390x with gcc
bpf/vmtest-bpf-VM_Test-17 fail Logs for test_progs_no_alu32 on x86_64 with gcc
bpf/vmtest-bpf-VM_Test-18 success Logs for test_progs_no_alu32 on x86_64 with llvm-16
bpf/vmtest-bpf-VM_Test-19 success Logs for test_progs_no_alu32_parallel on aarch64 with gcc
bpf/vmtest-bpf-VM_Test-20 success Logs for test_progs_no_alu32_parallel on x86_64 with gcc
bpf/vmtest-bpf-VM_Test-21 success Logs for test_progs_no_alu32_parallel on x86_64 with llvm-16
bpf/vmtest-bpf-VM_Test-22 success Logs for test_progs_parallel on aarch64 with gcc
bpf/vmtest-bpf-VM_Test-23 success Logs for test_progs_parallel on x86_64 with gcc
bpf/vmtest-bpf-VM_Test-24 success Logs for test_progs_parallel on x86_64 with llvm-16
bpf/vmtest-bpf-VM_Test-25 success Logs for test_verifier on aarch64 with gcc
bpf/vmtest-bpf-VM_Test-26 pending Logs for test_verifier on s390x with gcc
bpf/vmtest-bpf-VM_Test-27 success Logs for test_verifier on x86_64 with gcc
bpf/vmtest-bpf-VM_Test-28 success Logs for test_verifier on x86_64 with llvm-16
bpf/vmtest-bpf-VM_Test-29 success Logs for veristat

Commit Message

Tejun Heo July 11, 2023, 1:13 a.m. UTC 
Add ops.cpu_online/offline() which are invoked when CPUs come online and
offline respectively. As the enqueue path already automatically bypasses
tasks to the local dsq on a deactivated CPU, BPF schedulers are guaranteed
to see tasks only on CPUs which are between online() and offline().

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: David Vernet <dvernet@meta.com>
Acked-by: Josh Don <joshdon@google.com>
Acked-by: Hao Luo <haoluo@google.com>
Acked-by: Barret Rhoden <brho@google.com>
---
 include/linux/sched/ext.h | 18 ++++++++++++++++++
 kernel/sched/ext.c        | 18 +++++++++++++++++-
 2 files changed, 35 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/include/linux/sched/ext.h b/include/linux/sched/ext.h
index 8a275ec05ee1..c17957bd75df 100644
--- a/include/linux/sched/ext.h
+++ b/include/linux/sched/ext.h
@@ -377,6 +377,24 @@  struct sched_ext_ops {
 	 */
 	void (*cpu_release)(s32 cpu, struct scx_cpu_release_args *args);
 
+	/**
+	 * cpu_online - A CPU became online
+	 * @cpu: CPU which just came up
+	 *
+	 * @cpu just came online. @cpu doesn't call ops.enqueue() or run tasks
+	 * associated with other CPUs beforehand.
+	 */
+	void (*cpu_online)(s32 cpu);
+
+	/**
+	 * cpu_offline - A CPU is going offline
+	 * @cpu: CPU which is going offline
+	 *
+	 * @cpu is going offline. @cpu doesn't call ops.enqueue() or run tasks
+	 * associated with other CPUs afterwards.
+	 */
+	void (*cpu_offline)(s32 cpu);
+
 	/**
 	 * prep_enable - Prepare to enable BPF scheduling for a task
 	 * @p: task to prepare BPF scheduling for
diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index 1b83dddbdf10..e54d8c7d19a9 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -1392,7 +1392,8 @@  static int balance_scx(struct rq *rq, struct task_struct *prev,
 		 * emitted in scx_notify_pick_next_task().
 		 */
 		if (SCX_HAS_OP(cpu_acquire))
-			SCX_CALL_OP(0, cpu_acquire, cpu_of(rq), NULL);
+			SCX_CALL_OP(SCX_KF_UNLOCKED, cpu_acquire, cpu_of(rq),
+				    NULL);
 		rq->scx.cpu_released = false;
 	}
 
@@ -1852,6 +1853,18 @@  void __scx_update_idle(struct rq *rq, bool idle)
 #endif
 }
 
+static void rq_online_scx(struct rq *rq, enum rq_onoff_reason reason)
+{
+	if (SCX_HAS_OP(cpu_online) && reason == RQ_ONOFF_HOTPLUG)
+		SCX_CALL_OP(SCX_KF_REST, cpu_online, cpu_of(rq));
+}
+
+static void rq_offline_scx(struct rq *rq, enum rq_onoff_reason reason)
+{
+	if (SCX_HAS_OP(cpu_offline) && reason == RQ_ONOFF_HOTPLUG)
+		SCX_CALL_OP(SCX_KF_REST, cpu_offline, cpu_of(rq));
+}
+
 #else /* !CONFIG_SMP */
 
 static bool test_and_clear_cpu_idle(int cpu) { return false; }
@@ -2370,6 +2383,9 @@  DEFINE_SCHED_CLASS(ext) = {
 	.balance		= balance_scx,
 	.select_task_rq		= select_task_rq_scx,
 	.set_cpus_allowed	= set_cpus_allowed_scx,
+
+	.rq_online		= rq_online_scx,
+	.rq_offline		= rq_offline_scx,
 #endif
 
 	.task_tick		= task_tick_scx,