Commit 78399324 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'sched_ext-for-6.19-rc3-fixes' of... 

Merge tag 'sched_ext-for-6.19-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext

Pull sched_ext fixes from Tejun Heo:

 - Fix uninitialized @ret on alloc_percpu() failure leading to
   ERR_PTR(0)

 - Fix PREEMPT_RT warning when bypass load balancer sends IPI to offline
   CPU by using resched_cpu() instead of resched_curr()

 - Fix comment referring to renamed function

 - Update scx_show_state.py for scx_root and scx_aborting changes

* tag 'sched_ext-for-6.19-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
  tools/sched_ext: update scx_show_state.py for scx_aborting change
  tools/sched_ext: fix scx_show_state.py for scx_root change
  sched_ext: Use the resched_cpu() to replace resched_curr() in the bypass_lb_node()
  sched_ext: Fix some comments in ext.c
  sched_ext: fix uninitialized ret on alloc_percpu() failure
parents bba0b6a1 c9894e6f

kernel/sched/ext.c

+10 −13
Original line number Diff line number Diff line
@@ -1577,7 +1577,7 @@ static bool dequeue_task_scx(struct rq *rq, struct task_struct *p, int deq_flags 
	 *

	 * @p may go through multiple stopping <-> running transitions between

	 * here and put_prev_task_scx() if task attribute changes occur while

	 * balance_scx() leaves @rq unlocked. However, they don't contain any

	 * balance_one() leaves @rq unlocked. However, they don't contain any

	 * information meaningful to the BPF scheduler and can be suppressed by

	 * skipping the callbacks if the task is !QUEUED.

	 */
@@ -2372,7 +2372,7 @@ static void switch_class(struct rq *rq, struct task_struct *next) 
	 * preempted, and it regaining control of the CPU.

	 *

	 * ->cpu_release() complements ->cpu_acquire(), which is emitted the

	 *  next time that balance_scx() is invoked.

	 *  next time that balance_one() is invoked.

	 */

	if (!rq->scx.cpu_released) {

		if (SCX_HAS_OP(sch, cpu_release)) {
@@ -2478,7 +2478,7 @@ do_pick_task_scx(struct rq *rq, struct rq_flags *rf, bool force_scx) 
	}



	/*

	 * If balance_scx() is telling us to keep running @prev, replenish slice

	 * If balance_one() is telling us to keep running @prev, replenish slice

	 * if necessary and keep running @prev. Otherwise, pop the first one

	 * from the local DSQ.

	 */
@@ -3956,13 +3956,8 @@ static void bypass_lb_node(struct scx_sched *sch, int node) 
					     nr_donor_target, nr_target);

	}



	for_each_cpu(cpu, resched_mask) {

		struct rq *rq = cpu_rq(cpu);



		raw_spin_rq_lock_irq(rq);

		resched_curr(rq);

		raw_spin_rq_unlock_irq(rq);

	}

	for_each_cpu(cpu, resched_mask)

		resched_cpu(cpu);



	for_each_cpu_and(cpu, cpu_online_mask, node_mask) {

		u32 nr = READ_ONCE(cpu_rq(cpu)->scx.bypass_dsq.nr);
@@ -4025,7 +4020,7 @@ static DEFINE_TIMER(scx_bypass_lb_timer, scx_bypass_lb_timerfn); 
 *

 * - ops.dispatch() is ignored.

 *

 * - balance_scx() does not set %SCX_RQ_BAL_KEEP on non-zero slice as slice

 * - balance_one() does not set %SCX_RQ_BAL_KEEP on non-zero slice as slice

 *   can't be trusted. Whenever a tick triggers, the running task is rotated to

 *   the tail of the queue with core_sched_at touched.

 *
@@ -4783,8 +4778,10 @@ static struct scx_sched *scx_alloc_and_add_sched(struct sched_ext_ops *ops) 
	}



	sch->pcpu = alloc_percpu(struct scx_sched_pcpu);

	if (!sch->pcpu)

	if (!sch->pcpu) {

		ret = -ENOMEM;

		goto err_free_gdsqs;

	}



	sch->helper = kthread_run_worker(0, "sched_ext_helper");

	if (IS_ERR(sch->helper)) {
@@ -6067,7 +6064,7 @@ __bpf_kfunc bool scx_bpf_dsq_move_to_local(u64 dsq_id) 
		/*

		 * A successfully consumed task can be dequeued before it starts

		 * running while the CPU is trying to migrate other dispatched

		 * tasks. Bump nr_tasks to tell balance_scx() to retry on empty

		 * tasks. Bump nr_tasks to tell balance_one() to retry on empty

		 * local DSQ.

		 */

		dspc->nr_tasks++;

tools/sched_ext/scx_show_state.py

+6 −4
Original line number Diff line number Diff line
@@ -27,16 +27,18 @@ def read_static_key(name): 
def state_str(state):

    return prog['scx_enable_state_str'][state].string_().decode()



ops = prog['scx_ops']

root = prog['scx_root']

enable_state = read_atomic("scx_enable_state_var")



print(f'ops           : {ops.name.string_().decode()}')

if root:

    print(f'ops           : {root.ops.name.string_().decode()}')

else:

    print('ops           : ')

print(f'enabled       : {read_static_key("__scx_enabled")}')

print(f'switching_all : {read_int("scx_switching_all")}')

print(f'switched_all  : {read_static_key("__scx_switched_all")}')

print(f'enable_state  : {state_str(enable_state)} ({enable_state})')

print(f'in_softlockup : {prog["scx_in_softlockup"].value_()}')

print(f'breather_depth: {read_atomic("scx_breather_depth")}')

print(f'aborting      : {prog["scx_aborting"].value_()}')

print(f'bypass_depth  : {prog["scx_bypass_depth"].value_()}')

print(f'nr_rejected   : {read_atomic("scx_nr_rejected")}')

print(f'enable_seq    : {read_atomic("scx_enable_seq")}')