Commit 23c63a96 authored by Andrea Righi's avatar Andrea Righi Committed by Tejun Heo
Browse files

sched_ext: idle: Explicitly pass allowed cpumask to scx_select_cpu_dfl() 



Modify scx_select_cpu_dfl() to take the allowed cpumask as an explicit
argument, instead of implicitly using @p->cpus_ptr.

This prepares for future changes where arbitrary cpumasks may be passed
to the built-in idle CPU selection policy.

This is a pure refactoring with no functional changes.

Signed-off-by: default avatarAndrea Righi <arighi@nvidia.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 29f512f5

kernel/sched/ext.c

+1 −1
Original line number Diff line number Diff line
@@ -3392,7 +3392,7 @@ static int select_task_rq_scx(struct task_struct *p, int prev_cpu, int wake_flag 
	} else {

		s32 cpu;



		cpu = scx_select_cpu_dfl(p, prev_cpu, wake_flags, 0);

		cpu = scx_select_cpu_dfl(p, prev_cpu, wake_flags, NULL, 0);

		if (cpu >= 0) {

			p->scx.slice = SCX_SLICE_DFL;

			p->scx.ddsp_dsq_id = SCX_DSQ_LOCAL;

kernel/sched/ext_idle.c

+11 −9
Original line number Diff line number Diff line
@@ -438,9 +438,11 @@ static inline bool task_affinity_all(const struct task_struct *p) 
 * NOTE: tasks that can only run on 1 CPU are excluded by this logic, because

 * we never call ops.select_cpu() for them, see select_task_rq().

 */

s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, u64 flags)

s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags,

		       const struct cpumask *cpus_allowed, u64 flags)

{

	const struct cpumask *llc_cpus = NULL, *numa_cpus = NULL;

	const struct cpumask *allowed = cpus_allowed ?: p->cpus_ptr;

	int node = scx_cpu_node_if_enabled(prev_cpu);

	s32 cpu;
@@ -460,9 +462,9 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, u64 
		struct cpumask *local_cpus = this_cpu_cpumask_var_ptr(local_numa_idle_cpumask);

		const struct cpumask *cpus = numa_span(prev_cpu);



		if (task_affinity_all(p))

		if (allowed == p->cpus_ptr && task_affinity_all(p))

			numa_cpus = cpus;

		else if (cpus && cpumask_and(local_cpus, p->cpus_ptr, cpus))

		else if (cpus && cpumask_and(local_cpus, allowed, cpus))

			numa_cpus = local_cpus;

	}
@@ -470,9 +472,9 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, u64 
		struct cpumask *local_cpus = this_cpu_cpumask_var_ptr(local_llc_idle_cpumask);

		const struct cpumask *cpus = llc_span(prev_cpu);



		if (task_affinity_all(p))

		if (allowed == p->cpus_ptr && task_affinity_all(p))

			llc_cpus = cpus;

		else if (cpus && cpumask_and(local_cpus, p->cpus_ptr, cpus))

		else if (cpus && cpumask_and(local_cpus, allowed, cpus))

			llc_cpus = local_cpus;

	}
@@ -511,7 +513,7 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, u64 
		    cpu_rq(cpu)->scx.local_dsq.nr == 0 &&

		    (!(flags & SCX_PICK_IDLE_IN_NODE) || (waker_node == node)) &&

		    !cpumask_empty(idle_cpumask(waker_node)->cpu)) {

			if (cpumask_test_cpu(cpu, p->cpus_ptr))

			if (cpumask_test_cpu(cpu, allowed))

				goto out_unlock;

		}

	}
@@ -556,7 +558,7 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, u64 
		 * begin in prev_cpu's node and proceed to other nodes in

		 * order of increasing distance.

		 */

		cpu = scx_pick_idle_cpu(p->cpus_ptr, node, flags | SCX_PICK_IDLE_CORE);

		cpu = scx_pick_idle_cpu(allowed, node, flags | SCX_PICK_IDLE_CORE);

		if (cpu >= 0)

			goto out_unlock;
@@ -604,7 +606,7 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, u64 
	 * in prev_cpu's node and proceed to other nodes in order of

	 * increasing distance.

	 */

	cpu = scx_pick_idle_cpu(p->cpus_ptr, node, flags);

	cpu = scx_pick_idle_cpu(allowed, node, flags);



out_unlock:

	rcu_read_unlock();
@@ -858,7 +860,7 @@ __bpf_kfunc s32 scx_bpf_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, 
		goto prev_cpu;



#ifdef CONFIG_SMP

	cpu = scx_select_cpu_dfl(p, prev_cpu, wake_flags, 0);

	cpu = scx_select_cpu_dfl(p, prev_cpu, wake_flags, NULL, 0);

	if (cpu >= 0) {

		*is_idle = true;

		return cpu;

kernel/sched/ext_idle.h

+2 −1
Original line number Diff line number Diff line
@@ -27,7 +27,8 @@ static inline s32 scx_pick_idle_cpu(const struct cpumask *cpus_allowed, int node 
}

#endif /* CONFIG_SMP */



s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, u64 flags);

s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags,

		       const struct cpumask *cpus_allowed, u64 flags);

void scx_idle_enable(struct sched_ext_ops *ops);

void scx_idle_disable(void);

int scx_idle_init(void);