sched/balancing: Rename load_balance() => sched_balance_rq()

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

Also load_balance() has become somewhat of a misnomer: historically
it was the first and primary load-balancing function that was called,
but with the introduction of sched domains, it's become a lower
layer function that balances runqueues.

Rename it to sched_balance_rq() accordingly.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://lore.kernel.org/r/20240308111819.1101550-6-mingo@kernel.org

Documentation/scheduler/sched-domains.rst

@@ -41,11 +41,11 @@ The latter function takes two arguments: the runqueue of current CPU and whether
 the CPU was idle at the time the sched_tick() happened and iterates over all
 sched domains our CPU is on, starting from its base domain and going up the ->parent
 chain. While doing that, it checks to see if the current domain has exhausted its
-rebalance interval. If so, it runs load_balance() on that domain. It then checks
+rebalance interval. If so, it runs sched_balance_rq() on that domain. It then checks
 the parent sched_domain (if it exists), and the parent of the parent and so
 forth.
 
-Initially, load_balance() finds the busiest group in the current sched domain.
+Initially, sched_balance_rq() finds the busiest group in the current sched domain.
 If it succeeds, it looks for the busiest runqueue of all the CPUs' runqueues in
 that group. If it manages to find such a runqueue, it locks both our initial
 CPU's runqueue and the newly found busiest one and starts moving tasks from it

Documentation/scheduler/sched-stats.rst

@@ -77,53 +77,53 @@ domain<N> <cpumask> 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
 
 The first field is a bit mask indicating what cpus this domain operates over.
 
-The next 24 are a variety of load_balance() statistics in grouped into types
+The next 24 are a variety of sched_balance_rq() statistics in grouped into types
 of idleness (idle, busy, and newly idle):
 
-    1)  # of times in this domain load_balance() was called when the
+    1)  # of times in this domain sched_balance_rq() was called when the
         cpu was idle
-    2)  # of times in this domain load_balance() checked but found
+    2)  # of times in this domain sched_balance_rq() checked but found
         the load did not require balancing when the cpu was idle
-    3)  # of times in this domain load_balance() tried to move one or
+    3)  # of times in this domain sched_balance_rq() tried to move one or
         more tasks and failed, when the cpu was idle
     4)  sum of imbalances discovered (if any) with each call to
-        load_balance() in this domain when the cpu was idle
+        sched_balance_rq() in this domain when the cpu was idle
     5)  # of times in this domain pull_task() was called when the cpu
         was idle
     6)  # of times in this domain pull_task() was called even though
         the target task was cache-hot when idle
-    7)  # of times in this domain load_balance() was called but did
+    7)  # of times in this domain sched_balance_rq() was called but did
         not find a busier queue while the cpu was idle
     8)  # of times in this domain a busier queue was found while the
         cpu was idle but no busier group was found
-    9)  # of times in this domain load_balance() was called when the
+    9)  # of times in this domain sched_balance_rq() was called when the
         cpu was busy
-    10) # of times in this domain load_balance() checked but found the
+    10) # of times in this domain sched_balance_rq() checked but found the
         load did not require balancing when busy
-    11) # of times in this domain load_balance() tried to move one or
+    11) # of times in this domain sched_balance_rq() tried to move one or
         more tasks and failed, when the cpu was busy
     12) sum of imbalances discovered (if any) with each call to
-        load_balance() in this domain when the cpu was busy
+        sched_balance_rq() in this domain when the cpu was busy
     13) # of times in this domain pull_task() was called when busy
     14) # of times in this domain pull_task() was called even though the
         target task was cache-hot when busy
-    15) # of times in this domain load_balance() was called but did not
+    15) # of times in this domain sched_balance_rq() was called but did not
         find a busier queue while the cpu was busy
     16) # of times in this domain a busier queue was found while the cpu
         was busy but no busier group was found
 
-    17) # of times in this domain load_balance() was called when the
+    17) # of times in this domain sched_balance_rq() was called when the
         cpu was just becoming idle
-    18) # of times in this domain load_balance() checked but found the
+    18) # of times in this domain sched_balance_rq() checked but found the
         load did not require balancing when the cpu was just becoming idle
-    19) # of times in this domain load_balance() tried to move one or more
+    19) # of times in this domain sched_balance_rq() tried to move one or more
         tasks and failed, when the cpu was just becoming idle
     20) sum of imbalances discovered (if any) with each call to
-        load_balance() in this domain when the cpu was just becoming idle
+        sched_balance_rq() in this domain when the cpu was just becoming idle
     21) # of times in this domain pull_task() was called when newly idle
     22) # of times in this domain pull_task() was called even though the
         target task was cache-hot when just becoming idle
-    23) # of times in this domain load_balance() was called but did not
+    23) # of times in this domain sched_balance_rq() was called but did not
         find a busier queue while the cpu was just becoming idle
     24) # of times in this domain a busier queue was found while the cpu
         was just becoming idle but no busier group was found