From: Alex Shi <[email protected]>
SD_CLUSTER shares the CPU resources like llc tags or l2 cache, that's
easy confuse with SD_SHARE_PKG_RESOURCES. So let's specifical point
what the latter shares: LLC. That would reduce some confusing.
Suggested-by: Valentin Schneider <[email protected]>
Signed-off-by: Alex Shi <[email protected]>
To: [email protected]
To: [email protected]
To: Miaohe Lin <[email protected]>
To: Barry Song <[email protected]>
To: Mark Rutland <[email protected]>
To: Frederic Weisbecker <[email protected]>
To: Daniel Bristot de Oliveira <[email protected]>
To: Ben Segall <[email protected]>
To: Steven Rostedt <[email protected]>
To: Dietmar Eggemann <[email protected]>
To: Juri Lelli <[email protected]>
To: Ingo Molnar <[email protected]>
To: "Naveen N. Rao" <[email protected]>
To: "Aneesh Kumar K.V" <[email protected]>
To: Christophe Leroy <[email protected]>
Cc: "Gautham R. Shenoy" <[email protected]>
Cc: Yicong Yang <[email protected]>
Cc: Ricardo Neri <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Srikar Dronamraju <[email protected]>
Cc: Valentin Schneider <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Michael Ellerman <[email protected]>
---
arch/powerpc/kernel/smp.c | 6 +++---
include/linux/sched/sd_flags.h | 4 ++--
include/linux/sched/topology.h | 6 +++---
kernel/sched/fair.c | 2 +-
kernel/sched/topology.c | 16 ++++++++--------
5 files changed, 17 insertions(+), 17 deletions(-)
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 693334c20d07..a60e4139214b 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -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)
diff --git a/include/linux/sched/sd_flags.h b/include/linux/sched/sd_flags.h
index a8b28647aafc..b04a5d04dee9 100644
--- a/include/linux/sched/sd_flags.h
+++ b/include/linux/sched/sd_flags.h
@@ -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
diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h
index a6e04b4a21d7..191b122158fb 100644
--- a/include/linux/sched/topology.h
+++ b/include/linux/sched/topology.h
@@ -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
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 10ae28e1c088..188597640b1f 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -10695,7 +10695,7 @@ 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
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 0b33f7b05d21..e877730219d3 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -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;
--
2.43.0
On 07/02/24 11:58, [email protected] wrote:
> From: Alex Shi <[email protected]>
>
> SD_CLUSTER shares the CPU resources like llc tags or l2 cache, that's
> easy confuse with SD_SHARE_PKG_RESOURCES. So let's specifical point
> what the latter shares: LLC. That would reduce some confusing.
>
> Suggested-by: Valentin Schneider <[email protected]>
> Signed-off-by: Alex Shi <[email protected]>
AFAICT it's just missing the below replacement (I've stretched the comments
to go up to 80 chars while at it), otherwise LGTM.
Reviewed-by: Valentin Schneider <[email protected]>
---
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index e877730219d38..99ea5986038ce 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -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);
On Wed, Feb 07, 2024 at 11:58:40AM +0800, [email protected] wrote:
> From: Alex Shi <[email protected]>
>
> SD_CLUSTER shares the CPU resources like llc tags or l2 cache, that's
> easy confuse with SD_SHARE_PKG_RESOURCES. So let's specifical point
> what the latter shares: LLC. That would reduce some confusing.
>
> Suggested-by: Valentin Schneider <[email protected]>
> Signed-off-by: Alex Shi <[email protected]>
FWIW, Reviewed-by: Ricardo Neri <[email protected]>