Commit 79bec4c6 authored by Steve Sistare's avatar Steve Sistare Committed by Zheng Zengkai
Browse files

sched/topology: Provide hooks to allocate data shared per LLC 

hulk inclusion
category: feature
bugzilla: 38261, https://gitee.com/openeuler/kernel/issues/I49XPZ


CVE: NA

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

Add functions sd_llc_alloc_all() and sd_llc_free_all() to allocate and
free data pointed to by struct sched_domain_shared at the last-level-cache
domain.  sd_llc_alloc_all() is called after the SD hierarchy is known, to
eliminate the unnecessary allocations that would occur if we instead
allocated in __sdt_alloc() and then figured out which shared nodes are
redundant.

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>
Reviewed-by: default avatarChen Hui <judy.chenhui@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent bf693f72

kernel/sched/topology.c

+74 −1
Original line number Diff line number Diff line
@@ -10,6 +10,12 @@ DEFINE_MUTEX(sched_domains_mutex); 
static cpumask_var_t sched_domains_tmpmask;

static cpumask_var_t sched_domains_tmpmask2;



struct s_data;

static int sd_llc_alloc(struct sched_domain *sd);

static void sd_llc_free(struct sched_domain *sd);

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

static void sd_llc_free_all(const struct cpumask *cpu_map);



#ifdef CONFIG_SCHED_DEBUG



static int __init sched_debug_setup(char *str)
@@ -596,8 +602,10 @@ static void destroy_sched_domain(struct sched_domain *sd) 
	 */

	free_sched_groups(sd->groups, 1);



	if (sd->shared && atomic_dec_and_test(&sd->shared->ref))

	if (sd->shared && atomic_dec_and_test(&sd->shared->ref)) {

		sd_llc_free(sd);

		kfree(sd->shared);

	}

	kfree(sd);

}
@@ -1238,6 +1246,7 @@ static void __free_domain_allocs(struct s_data *d, enum s_alloc what, 
		free_percpu(d->sd);

		fallthrough;

	case sa_sd_storage:

		sd_llc_free_all(cpu_map);

		__sdt_free(cpu_map);

		fallthrough;

	case sa_none:
@@ -1849,6 +1858,62 @@ 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. */



	return 0;

}



static void sd_llc_free(struct sched_domain *sd)

{

	struct sched_domain_shared *sds = sd->shared;



	if (!sds)

		return;



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

}



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

{

	struct sched_domain *sd, *hsd;

	int i;



	for_each_cpu(i, cpu_map) {

		/* Find highest domain that shares resources */

		hsd = NULL;

		for (sd = *per_cpu_ptr(d->sd, i); sd; sd = sd->parent) {

			if (!(sd->flags & SD_SHARE_PKG_RESOURCES))

				break;

			hsd = sd;

		}

		if (hsd && sd_llc_alloc(hsd))

			return 1;

	}



	return 0;

}



static void sd_llc_free_all(const struct cpumask *cpu_map)

{

	struct sched_domain_topology_level *tl;

	struct sched_domain *sd;

	struct sd_data *sdd;

	int j;



	for_each_sd_topology(tl) {

		sdd = &tl->data;

		if (!sdd)

			continue;

		for_each_cpu(j, cpu_map) {

			sd = *per_cpu_ptr(sdd->sd, j);

			if (sd)

				sd_llc_free(sd);

		}

	}

}



static struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl,

		const struct cpumask *cpu_map, struct sched_domain_attr *attr,

		struct sched_domain *child, int dflags, int cpu)
@@ -2049,6 +2114,14 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att 
		}

	}



	/*

	 * Allocate shared sd data at last level cache.  Must be done after

	 * domains are built above, but before the data is used in

	 * cpu_attach_domain and descendants below.

	 */

	if (sd_llc_alloc_all(cpu_map, &d))

		goto error;



	/* Attach the domains */

	rcu_read_lock();

	for_each_cpu(i, cpu_map) {