Commit 126b3b68 authored by Tommaso Cucinotta's avatar Tommaso Cucinotta Committed by Ingo Molnar
Browse files

sched/deadline: Refactor CPU heap code 



 1. heapify up factored out in new dedicated function heapify_up()
    (avoids repetition of same code)

 2. call to cpudl_change_key() replaced with heapify_up() when
    cpudl_set actually inserts a new node in the heap

 3. cpudl_change_key() replaced with heapify() that heapifies up
    or down as needed.

Signed-off-by: default avatarTommaso Cucinotta <tommaso.cucinotta@sssup.it>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarLuca Abeni <luca.abeni@unitn.it>
Reviewed-by: default avatarJuri Lelli <juri.lelli@arm.com>
Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-dl@retis.sssup.it
Link: http://lkml.kernel.org/r/1471184828-12644-2-git-send-email-tommaso.cucinotta@sssup.it


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 97a7142f

kernel/sched/cpudeadline.c

+23 −27
Original line number Diff line number Diff line
@@ -41,7 +41,7 @@ static void cpudl_exchange(struct cpudl *cp, int a, int b) 
	swap(cp->elements[cpu_a].idx, cp->elements[cpu_b].idx);

}



static void cpudl_heapify(struct cpudl *cp, int idx)

static void cpudl_heapify_down(struct cpudl *cp, int idx)

{

	int l, r, largest;
@@ -66,21 +66,22 @@ static void cpudl_heapify(struct cpudl *cp, int idx) 
	}

}



static void cpudl_change_key(struct cpudl *cp, int idx, u64 new_dl)

static void cpudl_heapify_up(struct cpudl *cp, int idx)

{

	WARN_ON(idx == IDX_INVALID || !cpu_present(idx));



	if (dl_time_before(new_dl, cp->elements[idx].dl)) {

		cp->elements[idx].dl = new_dl;

		cpudl_heapify(cp, idx);

	} else {

		cp->elements[idx].dl = new_dl;

	while (idx > 0 && dl_time_before(cp->elements[parent(idx)].dl,

			cp->elements[idx].dl)) {

		cpudl_exchange(cp, idx, parent(idx));

		idx = parent(idx);

	}

}



static void cpudl_heapify(struct cpudl *cp, int idx)

{

	if (idx > 0 && dl_time_before(cp->elements[parent(idx)].dl,

				cp->elements[idx].dl))

		cpudl_heapify_up(cp, idx);

	else

		cpudl_heapify_down(cp, idx);

}



static inline int cpudl_maximum(struct cpudl *cp)
@@ -154,27 +155,22 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid) 
		cp->size--;

		cp->elements[new_cpu].idx = old_idx;

		cp->elements[cpu].idx = IDX_INVALID;

		while (old_idx > 0 && dl_time_before(

				cp->elements[parent(old_idx)].dl,

				cp->elements[old_idx].dl)) {

			cpudl_exchange(cp, old_idx, parent(old_idx));

			old_idx = parent(old_idx);

		}

		cpumask_set_cpu(cpu, cp->free_cpus);

		cpudl_heapify(cp, old_idx);

		cpumask_set_cpu(cpu, cp->free_cpus);



		goto out;

	}



	if (old_idx == IDX_INVALID) {

		cp->size++;

		cp->elements[cp->size - 1].dl = dl;

		cp->elements[cp->size - 1].cpu = cpu;

		cp->elements[cpu].idx = cp->size - 1;

		cpudl_change_key(cp, cp->size - 1, dl);

		int new_idx = cp->size++;

		cp->elements[new_idx].dl = dl;

		cp->elements[new_idx].cpu = cpu;

		cp->elements[cpu].idx = new_idx;

		cpudl_heapify_up(cp, new_idx);

		cpumask_clear_cpu(cpu, cp->free_cpus);

	} else {

		cpudl_change_key(cp, old_idx, dl);

		cp->elements[old_idx].dl = dl;

		cpudl_heapify(cp, old_idx);

	}



out:

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