sched: Remove USER_PRIO, TASK_USER_PRIO and MAX_USER_PRIO

The only remaining use of MAX_USER_PRIO (and USER_PRIO) is the
SCALE_PRIO() definition in the PowerPC Cell architecture's Synergistic
Processor Unit (SPU) scheduler. TASK_USER_PRIO isn't used anymore.

Commit fe443ef2ac42 ("[POWERPC] spusched: Dynamic timeslicing for
SCHED_OTHER") copied SCALE_PRIO() from the task scheduler in v2.6.23.

Commit a4ec24b48dde ("sched: tidy up SCHED_RR") removed it from the task
scheduler in v2.6.24.

Commit 3ee237dddcd8 ("sched/prio: Add 3 macros of MAX_NICE, MIN_NICE and
NICE_WIDTH in prio.h") introduced NICE_WIDTH much later.

With:

  MAX_USER_PRIO = USER_PRIO(MAX_PRIO)

                = MAX_PRIO - MAX_RT_PRIO

       MAX_PRIO = MAX_RT_PRIO + NICE_WIDTH

  MAX_USER_PRIO = MAX_RT_PRIO + NICE_WIDTH - MAX_RT_PRIO

  MAX_USER_PRIO = NICE_WIDTH

MAX_USER_PRIO can be replaced by NICE_WIDTH to be able to remove all the
{*_}USER_PRIO defines.

Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20210128131040.296856-3-dietmar.eggemann@arm.com

diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c
index f18d5067cd0fa96df0f2d470354491bd55a0ac02..aeb7f3922106a033e1063731bd3f8e0f1e0c262b 100644 (file)
--- a/arch/powerpc/platforms/cell/spufs/sched.c
+++ b/arch/powerpc/platforms/cell/spufs/sched.c
@@ -72,7 +72,7 @@ static struct timer_list spuloadavg_timer;
 #define DEF_SPU_TIMESLICE      (100 * HZ / (1000 * SPUSCHED_TICK))
 
 #define SCALE_PRIO(x, prio) \
-       max(x * (MAX_PRIO - prio) / (MAX_USER_PRIO / 2), MIN_SPU_TIMESLICE)
+       max(x * (MAX_PRIO - prio) / (NICE_WIDTH / 2), MIN_SPU_TIMESLICE)
 
 /*
  * scale user-nice values [ -20 ... 0 ... 19 ] to time slice values:

diff --git a/include/linux/sched/prio.h b/include/linux/sched/prio.h
index d111f2fd77ea790b058bf5f1eb54862204c68e8b..ab83d85e1183aa962e797e15e2d08fce6b976f84 100644 (file)
--- a/include/linux/sched/prio.h
+++ b/include/linux/sched/prio.h
@@ -26,15 +26,6 @@
 #define NICE_TO_PRIO(nice)     ((nice) + DEFAULT_PRIO)
 #define PRIO_TO_NICE(prio)     ((prio) - DEFAULT_PRIO)
 
-/*
- * 'User priority' is the nice value converted to something we
- * can work with better when scaling various scheduler parameters,
- * it's a [ 0 ... 39 ] range.
- */
-#define USER_PRIO(p)           ((p)-MAX_RT_PRIO)
-#define TASK_USER_PRIO(p)      USER_PRIO((p)->static_prio)
-#define MAX_USER_PRIO          (USER_PRIO(MAX_PRIO))
-
 /*
  * Convert nice value [19,-20] to rlimit style value [1,40].
  */

diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index f519aba2c542c4eb41bd198c032eee2943cf4844..2185b3b435a93496f2e2f543d5233e9f3b8ea63a 100644 (file)
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -140,7 +140,7 @@ extern void call_trace_sched_update_nr_running(struct rq *rq, int count);
  * scale_load() and scale_load_down(w) to convert between them. The
  * following must be true:
  *
- *  scale_load(sched_prio_to_weight[USER_PRIO(NICE_TO_PRIO(0))]) == NICE_0_LOAD
+ *  scale_load(sched_prio_to_weight[NICE_TO_PRIO(0)-MAX_RT_PRIO]) == NICE_0_LOAD
  *
  */
 #define NICE_0_LOAD            (1L << NICE_0_LOAD_SHIFT)