Commit 54de4427 authored by Alex Shi's avatar Alex Shi Committed by Ingo Molnar
Browse files

sched/topology: Rename SD_SHARE_PKG_RESOURCES to SD_SHARE_LLC 



SD_SHARE_PKG_RESOURCES is a bit of a misnomer: its naming suggests that
it's sharing all 'package resources' - while in reality it's specifically
for sharing the LLC only.

Rename it to SD_SHARE_LLC to reduce confusion.

[ mingo: Rewrote the confusing changelog as well. ]

Suggested-by: default avatarValentin Schneider <vschneid@redhat.com>
Signed-off-by: default avatarAlex Shi <alexs@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Reviewed-by: default avatarValentin Schneider <vschneid@redhat.com>
Reviewed-by: default avatarRicardo Neri <ricardo.neri-calderon@linux.intel.com>
Reviewed-by: default avatarBarry Song <baohua@kernel.org>
Link: https://lore.kernel.org/r/20240210113924.1130448-5-alexs@kernel.org
parent fbc44986

arch/powerpc/kernel/smp.c

+3 −3
Original line number Diff line number Diff line
@@ -984,7 +984,7 @@ static bool shared_caches __ro_after_init; 
/* cpumask of CPUs with asymmetric SMT dependency */

static int powerpc_smt_flags(void)

{

	int flags = SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;

	int flags = SD_SHARE_CPUCAPACITY | SD_SHARE_LLC;



	if (cpu_has_feature(CPU_FTR_ASYM_SMT)) {

		printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n");
@@ -1010,9 +1010,9 @@ static __ro_after_init DEFINE_STATIC_KEY_FALSE(splpar_asym_pack); 
static int powerpc_shared_cache_flags(void)

{

	if (static_branch_unlikely(&splpar_asym_pack))

		return SD_SHARE_PKG_RESOURCES | SD_ASYM_PACKING;

		return SD_SHARE_LLC | SD_ASYM_PACKING;



	return SD_SHARE_PKG_RESOURCES;

	return SD_SHARE_LLC;

}



static int powerpc_shared_proc_flags(void)

include/linux/sched/sd_flags.h

+2 −2
Original line number Diff line number Diff line
@@ -117,13 +117,13 @@ SD_FLAG(SD_SHARE_CPUCAPACITY, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS) 
SD_FLAG(SD_CLUSTER, SDF_NEEDS_GROUPS)



/*

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

 * Domain members share CPU Last Level Caches

 *

 * SHARED_CHILD: Set from the base domain up until spanned CPUs no longer share

 *               the same cache(s).

 * NEEDS_GROUPS: Caches are shared between groups.

 */

SD_FLAG(SD_SHARE_PKG_RESOURCES, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS)

SD_FLAG(SD_SHARE_LLC, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS)



/*

 * Only a single load balancing instance

include/linux/sched/topology.h

+3 −3
Original line number Diff line number Diff line
@@ -38,21 +38,21 @@ extern const struct sd_flag_debug sd_flag_debug[]; 
#ifdef CONFIG_SCHED_SMT

static inline int cpu_smt_flags(void)

{

	return SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;

	return SD_SHARE_CPUCAPACITY | SD_SHARE_LLC;

}

#endif



#ifdef CONFIG_SCHED_CLUSTER

static inline int cpu_cluster_flags(void)

{

	return SD_CLUSTER | SD_SHARE_PKG_RESOURCES;

	return SD_CLUSTER | SD_SHARE_LLC;

}

#endif



#ifdef CONFIG_SCHED_MC

static inline int cpu_core_flags(void)

{

	return SD_SHARE_PKG_RESOURCES;

	return SD_SHARE_LLC;

}

#endif

kernel/sched/fair.c

+1 −1
Original line number Diff line number Diff line
@@ -10678,7 +10678,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s 
	 */

	if (local->group_type == group_has_spare) {

		if ((busiest->group_type > group_fully_busy) &&

		    !(env->sd->flags & SD_SHARE_PKG_RESOURCES)) {

		    !(env->sd->flags & SD_SHARE_LLC)) {

			/*

			 * If busiest is overloaded, try to fill spare

			 * capacity. This might end up creating spare capacity

kernel/sched/topology.c

+14 −14
Original line number Diff line number Diff line
@@ -657,13 +657,13 @@ static void destroy_sched_domains(struct sched_domain *sd) 
}



/*

 * Keep a special pointer to the highest sched_domain that has

 * SD_SHARE_PKG_RESOURCE set (Last Level Cache Domain) for this

 * allows us to avoid some pointer chasing select_idle_sibling().

 * Keep a special pointer to the highest sched_domain that has SD_SHARE_LLC set

 * (Last Level Cache Domain) for this allows us to avoid some pointer chasing

 * select_idle_sibling().

 *

 * Also keep a unique ID per domain (we use the first CPU number in

 * the cpumask of the domain), this allows us to quickly tell if

 * two CPUs are in the same cache domain, see cpus_share_cache().

 * Also keep a unique ID per domain (we use the first CPU number in the cpumask

 * of the domain), this allows us to quickly tell if two CPUs are in the same

 * cache domain, see cpus_share_cache().

 */

DEFINE_PER_CPU(struct sched_domain __rcu *, sd_llc);

DEFINE_PER_CPU(int, sd_llc_size);
@@ -684,7 +684,7 @@ static void update_top_cache_domain(int cpu) 
	int id = cpu;

	int size = 1;



	sd = highest_flag_domain(cpu, SD_SHARE_PKG_RESOURCES);

	sd = highest_flag_domain(cpu, SD_SHARE_LLC);

	if (sd) {

		id = cpumask_first(sched_domain_span(sd));

		size = cpumask_weight(sched_domain_span(sd));
@@ -1554,7 +1554,7 @@ static struct cpumask ***sched_domains_numa_masks; 
 * function. For details, see include/linux/sched/sd_flags.h.

 *

 *   SD_SHARE_CPUCAPACITY

 *   SD_SHARE_PKG_RESOURCES

 *   SD_SHARE_LLC

 *   SD_CLUSTER

 *   SD_NUMA

 *
@@ -1566,7 +1566,7 @@ static struct cpumask ***sched_domains_numa_masks; 
#define TOPOLOGY_SD_FLAGS		\

	(SD_SHARE_CPUCAPACITY	|	\

	 SD_CLUSTER		|	\

	 SD_SHARE_PKG_RESOURCES |	\

	 SD_SHARE_LLC		|	\

	 SD_NUMA		|	\

	 SD_ASYM_PACKING)
@@ -1609,7 +1609,7 @@ sd_init(struct sched_domain_topology_level *tl, 
					| 0*SD_BALANCE_WAKE

					| 1*SD_WAKE_AFFINE

					| 0*SD_SHARE_CPUCAPACITY

					| 0*SD_SHARE_PKG_RESOURCES

					| 0*SD_SHARE_LLC

					| 0*SD_SERIALIZE

					| 1*SD_PREFER_SIBLING

					| 0*SD_NUMA
@@ -1646,7 +1646,7 @@ sd_init(struct sched_domain_topology_level *tl, 
	if (sd->flags & SD_SHARE_CPUCAPACITY) {

		sd->imbalance_pct = 110;



	} else if (sd->flags & SD_SHARE_PKG_RESOURCES) {

	} else if (sd->flags & SD_SHARE_LLC) {

		sd->imbalance_pct = 117;

		sd->cache_nice_tries = 1;
@@ -1671,7 +1671,7 @@ sd_init(struct sched_domain_topology_level *tl, 
	 * For all levels sharing cache; connect a sched_domain_shared

	 * instance.

	 */

	if (sd->flags & SD_SHARE_PKG_RESOURCES) {

	if (sd->flags & SD_SHARE_LLC) {

		sd->shared = *per_cpu_ptr(sdd->sds, sd_id);

		atomic_inc(&sd->shared->ref);

		atomic_set(&sd->shared->nr_busy_cpus, sd_weight);
@@ -2446,8 +2446,8 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att 
		for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) {

			struct sched_domain *child = sd->child;



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

			    (child->flags & SD_SHARE_PKG_RESOURCES)) {

			if (!(sd->flags & SD_SHARE_LLC) && child &&

			    (child->flags & SD_SHARE_LLC)) {

				struct sched_domain __rcu *top_p;

				unsigned int nr_llcs;