Commit 53ad6bf7 authored by Barry Song's avatar Barry Song Committed by Jie Liu
Browse files

sched: Add per_cpu cluster domain info and cpus_share_lowest_cache API 

kunpeng inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5W44S
CVE: NA

Reference: https://lore.kernel.org/lkml/20220915073423.25535-1-yangyicong@huawei.com/



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

Add per-cpu cluster domain info and cpus_share_lowest_cache() API.
This is the preparation for the optimization of select_idle_cpu()
on platforms with cluster scheduler level.

Tested-by: default avatarK Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: default avatarBarry Song <song.bao.hua@hisilicon.com>
Signed-off-by: default avatarYicong Yang <yangyicong@hisilicon.com>
Reviewed-by: default avatarGautham R. Shenoy <gautham.shenoy@amd.com>
Reviewed-by: default avatarTim Chen <tim.c.chen@linux.intel.com>
Reviewed-by: default avatarVincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: default avatarJie Liu <liujie375@h-partners.com>
parent 9895e9ad

include/linux/sched/sd_flags.h

+7 −0
Original line number Diff line number Diff line
@@ -99,6 +99,13 @@ SD_FLAG(SD_ASYM_CPUCAPACITY, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS) 
 */

SD_FLAG(SD_SHARE_CPUCAPACITY, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS)



/*

 * Domain members share CPU cluster (LLC tags or L2 cache)

 *

 * NEEDS_GROUPS: Clusters are shared between groups.

 */

SD_FLAG(SD_CLUSTER, SDF_NEEDS_GROUPS)



/*

 * Domain members share CPU package resources (i.e. caches)

 *

include/linux/sched/topology.h

+7 −1
Original line number Diff line number Diff line
@@ -46,7 +46,7 @@ static inline int cpu_smt_flags(void) 
#ifdef CONFIG_SCHED_CLUSTER

static inline int cpu_cluster_flags(void)

{

	return SD_SHARE_PKG_RESOURCES;

	return SD_CLUSTER | SD_SHARE_PKG_RESOURCES;

}

#endif
@@ -185,6 +185,7 @@ cpumask_var_t *alloc_sched_domains(unsigned int ndoms); 
void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);



bool cpus_share_cache(int this_cpu, int that_cpu);

bool cpus_share_lowest_cache(int this_cpu, int that_cpu);



typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);

typedef int (*sched_domain_flags_f)(void);
@@ -238,6 +239,11 @@ static inline bool cpus_share_cache(int this_cpu, int that_cpu) 
	return true;

}



static inline bool cpus_share_lowest_cache(int this_cpu, int that_cpu)

{

	return true;

}



#endif	/* !CONFIG_SMP */



#ifndef arch_scale_cpu_capacity

kernel/sched/core.c

+12 −0
Original line number Diff line number Diff line
@@ -3014,6 +3014,18 @@ bool cpus_share_cache(int this_cpu, int that_cpu) 
	return per_cpu(sd_llc_id, this_cpu) == per_cpu(sd_llc_id, that_cpu);

}



/*

 * Whether CPUs are share lowest cache, which means LLC on non-cluster

 * machines and LLC tag or L2 on machines with clusters.

 */

bool cpus_share_lowest_cache(int this_cpu, int that_cpu)

{

	if (this_cpu == that_cpu)

		return true;



	return per_cpu(sd_lowest_cache_id, this_cpu) == per_cpu(sd_lowest_cache_id, that_cpu);

}



static inline bool ttwu_queue_cond(int cpu, int wake_flags)

{

	/*

kernel/sched/sched.h

+2 −0
Original line number Diff line number Diff line
@@ -1801,7 +1801,9 @@ static inline struct sched_domain *lowest_flag_domain(int cpu, int flag) 
DECLARE_PER_CPU(struct sched_domain __rcu *, sd_llc);

DECLARE_PER_CPU(int, sd_llc_size);

DECLARE_PER_CPU(int, sd_llc_id);

DECLARE_PER_CPU(int, sd_lowest_cache_id);

DECLARE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared);

DECLARE_PER_CPU(struct sched_domain __rcu *, sd_cluster);

DECLARE_PER_CPU(struct sched_domain __rcu *, sd_numa);

DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing);

DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity);

kernel/sched/topology.c

+15 −0
Original line number Diff line number Diff line
@@ -647,6 +647,8 @@ static void destroy_sched_domains(struct sched_domain *sd) 
DEFINE_PER_CPU(struct sched_domain __rcu *, sd_llc);

DEFINE_PER_CPU(int, sd_llc_size);

DEFINE_PER_CPU(int, sd_llc_id);

DEFINE_PER_CPU(int, sd_lowest_cache_id);

DEFINE_PER_CPU(struct sched_domain __rcu *, sd_cluster);

DEFINE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared);

DEFINE_PER_CPU(struct sched_domain __rcu *, sd_numa);

DEFINE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing);
@@ -682,6 +684,18 @@ static void update_top_cache_domain(int cpu) 
	per_cpu(sd_llc_id, cpu) = id;

	rcu_assign_pointer(per_cpu(sd_llc_shared, cpu), sds);



	sd = lowest_flag_domain(cpu, SD_CLUSTER);

	if (sd)

		id = cpumask_first(sched_domain_span(sd));

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



	/*

	 * This assignment should be placed after the sd_llc_id as

	 * we want this id equals to cluster id on cluster machines

	 * but equals to LLC id on non-Cluster machines.

	 */

	per_cpu(sd_lowest_cache_id, cpu) = id;



	sd = lowest_flag_domain(cpu, SD_NUMA);

	rcu_assign_pointer(per_cpu(sd_numa, cpu), sd);
@@ -1406,6 +1420,7 @@ int __read_mostly node_reclaim_distance = RECLAIM_DISTANCE; 
 */

#define TOPOLOGY_SD_FLAGS		\

	(SD_SHARE_CPUCAPACITY	|	\

	 SD_CLUSTER		|	\

	 SD_SHARE_PKG_RESOURCES |	\

	 SD_NUMA		|	\

	 SD_ASYM_PACKING)