From 4ff8f2ca6ccd9e0cc5665d09f86d631b3ae3a14c Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Tue, 22 Feb 2022 14:51:58 +0100
Subject: sched/headers: Reorganize, clean up and optimize kernel/sched/sched.h
 dependencies

Remove all headers, except the ones required to make this header
build standalone.

Also include stats.h in sched.h explicitly - dependencies already
require this.

Summary of the build speedup gained through the last ~15 scheduler build &
header dependency patches:

Cumulative scheduler (kernel/sched/) build time speedup on a
Linux distribution's config, which enables all scheduler features,
compared to the vanilla kernel:

  _____________________________________________________________________________
 |
 |  Vanilla kernel (v5.13-rc7):
 |_____________________________________________________________________________
 |
 |  Performance counter stats for 'make -j96 kernel/sched/' (3 runs):
 |
 |   126,975,564,374      instructions              #    1.45  insn per cycle           ( +-  0.00% )
 |    87,637,847,671      cycles                    #    3.959 GHz                      ( +-  0.30% )
 |         22,136.96 msec cpu-clock                 #    7.499 CPUs utilized            ( +-  0.29% )
 |
 |            2.9520 +- 0.0169 seconds time elapsed  ( +-  0.57% )
 |_____________________________________________________________________________
 |
 |  Patched kernel:
 |_____________________________________________________________________________
 |
 | Performance counter stats for 'make -j96 kernel/sched/' (3 runs):
 |
 |    50,420,496,914      instructions              #    1.47  insn per cycle           ( +-  0.00% )
 |    34,234,322,038      cycles                    #    3.946 GHz                      ( +-  0.31% )
 |          8,675.81 msec cpu-clock                 #    3.053 CPUs utilized            ( +-  0.45% )
 |
 |            2.8420 +- 0.0181 seconds time elapsed  ( +-  0.64% )
 |_____________________________________________________________________________

Summary:

  - CPU time used to build the scheduler dropped by -60.9%, a reduction
    from 22.1 clock-seconds to 8.7 clock-seconds.

  - Wall-clock time to build the scheduler dropped by -3.9%, a reduction
    from 2.95 seconds to 2.84 seconds.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
---
 kernel/sched/build_policy.c | 4 ----
 1 file changed, 4 deletions(-)

(limited to 'kernel/sched/build_policy.c')

diff --git a/kernel/sched/build_policy.c b/kernel/sched/build_policy.c
index a2e4023771a0..e0104b45029a 100644
--- a/kernel/sched/build_policy.c
+++ b/kernel/sched/build_policy.c
@@ -28,10 +28,6 @@
 #include <linux/tsacct_kern.h>
 #include <linux/vtime.h>
 
-#ifdef CONFIG_PARAVIRT
-# include <asm/paravirt.h>
-#endif
-
 #include <uapi/linux/sched/types.h>
 
 #include "sched.h"
-- 
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