[PATCH 08/13] sched/balancing: Rename find_busiest_group() => sched_balance_find_src_group()

From: Ingo Molnar
Date: Fri Mar 08 2024 - 06:20:31 EST


Make two naming changes:

1)
Standardize scheduler load-balancing function names on the
sched_balance_() prefix.

2)

Similar to find_busiest_queue(), the find_busiest_group() naming
has become a bit of a misnomer: the 'busiest' qualifier to this
function was historically correct but in the current code
in quite a few cases we will not pick the 'busiest' group - but the best
(possible) group we can balance from based on a complex set of
constraints.

So name it a bit more neutrally, similar to the 'src/dst' nomenclature
we are already using when moving tasks between runqueues, and also
use the sched_balance_ prefix: sched_balance_find_src_group().

Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Shrikanth Hegde <sshegde@xxxxxxxxxxxxx>
Cc: Valentin Schneider <vschneid@xxxxxxxxxx>
Cc: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
---
kernel/sched/fair.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 1cd9a18b35e0..96a81b2fa281 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -9430,7 +9430,7 @@ static void update_blocked_averages(int cpu)
rq_unlock_irqrestore(rq, &rf);
}

-/********** Helpers for find_busiest_group ************************/
+/********** Helpers for sched_balance_find_src_group ************************/

/*
* sg_lb_stats - stats of a sched_group required for load-balancing:
@@ -9637,7 +9637,7 @@ static inline int check_misfit_status(struct rq *rq, struct sched_domain *sd)
*
* When this is so detected; this group becomes a candidate for busiest; see
* update_sd_pick_busiest(). And calculate_imbalance() and
- * find_busiest_group() avoid some of the usual balance conditions to allow it
+ * sched_balance_find_src_group() avoid some of the usual balance conditions to allow it
* to create an effective group imbalance.
*
* This is a somewhat tricky proposition since the next run might not find the
@@ -10788,7 +10788,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
) / SCHED_CAPACITY_SCALE;
}

-/******* find_busiest_group() helpers end here *********************/
+/******* sched_balance_find_src_group() helpers end here *********************/

/*
* Decision matrix according to the local and busiest group type:
@@ -10811,7 +10811,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
*/

/**
- * find_busiest_group - Returns the busiest group within the sched_domain
+ * sched_balance_find_src_group - Returns the busiest group within the sched_domain
* if there is an imbalance.
* @env: The load balancing environment.
*
@@ -10820,7 +10820,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
*
* Return: - The busiest group if imbalance exists.
*/
-static struct sched_group *find_busiest_group(struct lb_env *env)
+static struct sched_group *sched_balance_find_src_group(struct lb_env *env)
{
struct sg_lb_stats *local, *busiest;
struct sd_lb_stats sds;
@@ -11274,7 +11274,7 @@ static int sched_balance_rq(int this_cpu, struct rq *this_rq,
goto out_balanced;
}

- group = find_busiest_group(&env);
+ group = sched_balance_find_src_group(&env);
if (!group) {
schedstat_inc(sd->lb_nobusyg[idle]);
goto out_balanced;
@@ -11298,7 +11298,7 @@ static int sched_balance_rq(int this_cpu, struct rq *this_rq,
env.flags |= LBF_ALL_PINNED;
if (busiest->nr_running > 1) {
/*
- * Attempt to move tasks. If find_busiest_group has found
+ * Attempt to move tasks. If sched_balance_find_src_group has found
* an imbalance but busiest->nr_running <= 1, the group is
* still unbalanced. ld_moved simply stays zero, so it is
* correctly treated as an imbalance.
--
2.40.1