[RFC PATCH 1/3] sched: Rename cpus_share_cache to cpus_share_llc

From: Mathieu Desnoyers
Date: Fri Aug 18 2023 - 11:30:23 EST


In preparation for introducing cpus_share_l2c, rename cpus_share_cache
to cpus_share_llc, to make it clear that it specifically groups CPUs by
LLC.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Valentin Schneider <vschneid@xxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Ben Segall <bsegall@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>
Cc: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
Cc: Juri Lelli <juri.lelli@xxxxxxxxxx>
Cc: Swapnil Sapkal <Swapnil.Sapkal@xxxxxxx>
Cc: Aaron Lu <aaron.lu@xxxxxxxxx>
Cc: Julien Desfossez <jdesfossez@xxxxxxxxxxxxxxxx>
Cc: x86@xxxxxxxxxx
---
block/blk-mq.c | 2 +-
include/linux/sched/topology.h | 4 ++--
kernel/sched/core.c | 4 ++--
kernel/sched/fair.c | 8 ++++----
kernel/sched/topology.c | 2 +-
5 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index b9f454613989..ed1457ca2c6d 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1136,7 +1136,7 @@ static inline bool blk_mq_complete_need_ipi(struct request *rq)
/* same CPU or cache domain? Complete locally */
if (cpu == rq->mq_ctx->cpu ||
(!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags) &&
- cpus_share_cache(cpu, rq->mq_ctx->cpu)))
+ cpus_share_llc(cpu, rq->mq_ctx->cpu)))
return false;

/* don't try to IPI to an offline CPU */
diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h
index 816df6cc444e..7f9331f71260 100644
--- a/include/linux/sched/topology.h
+++ b/include/linux/sched/topology.h
@@ -178,7 +178,7 @@ extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
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_llc(int this_cpu, int that_cpu);

typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
typedef int (*sched_domain_flags_f)(void);
@@ -227,7 +227,7 @@ partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
{
}

-static inline bool cpus_share_cache(int this_cpu, int that_cpu)
+static inline bool cpus_share_llc(int this_cpu, int that_cpu)
{
return true;
}
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index a68d1276bab0..d096ce815099 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3904,7 +3904,7 @@ void wake_up_if_idle(int cpu)
rcu_read_unlock();
}

-bool cpus_share_cache(int this_cpu, int that_cpu)
+bool cpus_share_llc(int this_cpu, int that_cpu)
{
if (this_cpu == that_cpu)
return true;
@@ -3929,7 +3929,7 @@ static inline bool ttwu_queue_cond(struct task_struct *p, int cpu)
* If the CPU does not share cache, then queue the task on the
* remote rqs wakelist to avoid accessing remote data.
*/
- if (!cpus_share_cache(smp_processor_id(), cpu))
+ if (!cpus_share_llc(smp_processor_id(), cpu))
return true;

if (cpu == smp_processor_id())
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 4da5f3541762..680bbe0c7d7a 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6626,7 +6626,7 @@ wake_affine_idle(int this_cpu, int prev_cpu, int sync)
* a cpufreq perspective, it's better to have higher utilisation
* on one CPU.
*/
- if (available_idle_cpu(this_cpu) && cpus_share_cache(this_cpu, prev_cpu))
+ if (available_idle_cpu(this_cpu) && cpus_share_llc(this_cpu, prev_cpu))
return available_idle_cpu(prev_cpu) ? prev_cpu : this_cpu;

if (sync && cpu_rq(this_cpu)->nr_running == 1)
@@ -7146,7 +7146,7 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target)
/*
* If the previous CPU is cache affine and idle, don't be stupid:
*/
- if (prev != target && cpus_share_cache(prev, target) &&
+ if (prev != target && cpus_share_llc(prev, target) &&
(available_idle_cpu(prev) || sched_idle_cpu(prev)) &&
asym_fits_cpu(task_util, util_min, util_max, prev))
return prev;
@@ -7172,7 +7172,7 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target)
p->recent_used_cpu = prev;
if (recent_used_cpu != prev &&
recent_used_cpu != target &&
- cpus_share_cache(recent_used_cpu, target) &&
+ cpus_share_llc(recent_used_cpu, target) &&
(available_idle_cpu(recent_used_cpu) || sched_idle_cpu(recent_used_cpu)) &&
cpumask_test_cpu(p->recent_used_cpu, p->cpus_ptr) &&
asym_fits_cpu(task_util, util_min, util_max, recent_used_cpu)) {
@@ -7206,7 +7206,7 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target)
if (sched_smt_active()) {
has_idle_core = test_idle_cores(target);

- if (!has_idle_core && cpus_share_cache(prev, target)) {
+ if (!has_idle_core && cpus_share_llc(prev, target)) {
i = select_idle_smt(p, prev);
if ((unsigned int)i < nr_cpumask_bits)
return i;
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 6682535e37c8..1ae2a0a1115a 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -661,7 +661,7 @@ static void destroy_sched_domains(struct sched_domain *sd)
*
* 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().
+ * two CPUs are in the same cache domain, see cpus_share_llc().
*/
DEFINE_PER_CPU(struct sched_domain __rcu *, sd_llc);
DEFINE_PER_CPU(int, sd_llc_size);
--
2.39.2