Commit b3cf6ed8 authored by Steve Sistare's avatar Steve Sistare Committed by Cheng Jian
Browse files

sched/topology: Provide cfs_overload_cpus bitmap 

hulk inclusion
category: feature
bugzilla: 38261, https://bugzilla.openeuler.org/show_bug.cgi?id=23


CVE: NA

---------------------------

Define and initialize a sparse bitmap of overloaded CPUs, per
last-level-cache scheduling domain, for use by the CFS scheduling class.
Save a pointer to cfs_overload_cpus in the rq for efficient access.

Signed-off-by: default avatarSteve Sistare <steven.sistare@oracle.com>
Signed-off-by: default avatarCheng Jian <cj.chengjian@huawei.com>
Reviewed-by: default avatarHanjun Guo <guohanjun@huawei.com>
Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
Reviewed-by: default avatarXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
parent ef175d23

include/linux/sched/topology.h

+1 −0
Original line number Diff line number Diff line
@@ -72,6 +72,7 @@ struct sched_domain_shared { 
	atomic_t	ref;

	atomic_t	nr_busy_cpus;

	int		has_idle_cores;

	struct sparsemask *cfs_overload_cpus;

};



struct sched_domain {

kernel/sched/sched.h

+2 −0
Original line number Diff line number Diff line
@@ -83,6 +83,7 @@ 


struct rq;

struct cpuidle_state;

struct sparsemask;



/* task_struct::on_rq states: */

#define TASK_ON_RQ_QUEUED	1
@@ -829,6 +830,7 @@ struct rq { 
	struct cfs_rq		cfs;

	struct rt_rq		rt;

	struct dl_rq		dl;

	struct sparsemask	*cfs_overload_cpus;



#ifdef CONFIG_FAIR_GROUP_SCHED

	/* list of leaf cfs_rq on this CPU: */

kernel/sched/topology.c

+23 −2
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
 * Scheduler topology setup/handling methods

 */

#include "sched.h"

#include "sparsemask.h"



DEFINE_MUTEX(sched_domains_mutex);
@@ -409,7 +410,9 @@ DEFINE_PER_CPU(struct sched_domain *, sd_asym); 


static void update_top_cache_domain(int cpu)

{

	struct sparsemask *cfs_overload_cpus = NULL;

	struct sched_domain_shared *sds = NULL;

	struct rq *rq = cpu_rq(cpu);

	struct sched_domain *sd;

	int id = cpu;

	int size = 1;
@@ -419,8 +422,10 @@ static void update_top_cache_domain(int cpu) 
		id = cpumask_first(sched_domain_span(sd));

		size = cpumask_weight(sched_domain_span(sd));

		sds = sd->shared;

		cfs_overload_cpus = sds->cfs_overload_cpus;

	}



	rcu_assign_pointer(rq->cfs_overload_cpus, cfs_overload_cpus);

	rcu_assign_pointer(per_cpu(sd_llc, cpu), sd);

	per_cpu(sd_llc_size, cpu) = size;

	per_cpu(sd_llc_id, cpu) = id;
@@ -1613,7 +1618,22 @@ static void __sdt_free(const struct cpumask *cpu_map) 


static int sd_llc_alloc(struct sched_domain *sd)

{

	/* Allocate sd->shared data here. Empty for now. */

	struct sched_domain_shared *sds = sd->shared;

	struct cpumask *span = sched_domain_span(sd);

	int nid = cpu_to_node(cpumask_first(span));

	int flags = __GFP_ZERO | GFP_KERNEL;

	struct sparsemask *mask;



	/*

	 * Allocate the bitmap if not already allocated.  This is called for

	 * every CPU in the LLC but only allocates once per sd_llc_shared.

	 */

	if (!sds->cfs_overload_cpus) {

		mask = sparsemask_alloc_node(nr_cpu_ids, 3, flags, nid);

		if (!mask)

			return 1;

		sds->cfs_overload_cpus = mask;

	}



	return 0;

}
@@ -1625,7 +1645,8 @@ static void sd_llc_free(struct sched_domain *sd) 
	if (!sds)

		return;



	/* Free data here. Empty for now. */

	sparsemask_free(sds->cfs_overload_cpus);

	sds->cfs_overload_cpus = NULL;

}



static int sd_llc_alloc_all(const struct cpumask *cpu_map, struct s_data *d)