sched/balancing: Rename find_busiest_group() => sched_balance_find_src_group()

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@kernel.org>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://lore.kernel.org/r/20240308111819.1101550-9-mingo@kernel.org

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 1cd9a18b35e09c103ed696662df219f316d653ae..96a81b2fa281f1bbc12f8fdbaa9fdec699c14190 100644 (file)
--- 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 @@ redo:
                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 @@ redo:
        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.