[PATCH 00/15] sched/headers: Optimize scheduler build time

[PATCH 00/15] sched/headers: Optimize scheduler build time

[Ingo Molnar]

Optimize the kernel scheduler build time by organizing the code into
larger build units. This cuts CPU usage by 60%.

These patches originate from the fast-headers tree.

The numbers:

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.

Ingo Molnar (15):
  sched/headers: Fix header to build standalone: <linux/sched_clock.h>
  sched/headers: Add header guard to kernel/sched/sched.h
  sched/headers: Add header guard to kernel/sched/stats.h and kernel/sched/autogroup.h
  sched/headers: sched/clock: Mark all functions 'notrace', remove CC_FLAGS_FTRACE build asymmetry
  sched/headers: Add initial new headers as identity mappings
  sched/headers: Fix comment typo in kernel/sched/cpudeadline.c
  sched/headers: Make the <linux/sched/deadline.h> header build standalone
  sched/headers: Introduce kernel/sched/build_utility.c and build multiple .c files there
  sched/headers: Introduce kernel/sched/build_policy.c and build multiple .c files there
  sched/headers: Standardize kernel/sched/sched.h header dependencies
  sched/headers: Reorganize, clean up and optimize kernel/sched/core.c dependencies
  sched/headers: Reorganize, clean up and optimize kernel/sched/fair.c dependencies
  sched/headers: Reorganize, clean up and optimize kernel/sched/build_policy.c dependencies
  sched/headers: Reorganize, clean up and optimize kernel/sched/build_utility.c dependencies
  sched/headers: Reorganize, clean up and optimize kernel/sched/sched.h dependencies

 arch/arm64/include/asm/paravirt_api_clock.h |   1 +
 arch/x86/include/asm/paravirt_api_clock.h   |   1 +
 include/linux/cgroup_api.h                  |   1 +
 include/linux/cpumask_api.h                 |   1 +
 include/linux/fs_api.h                      |   1 +
 include/linux/gfp_api.h                     |   1 +
 include/linux/hashtable_api.h               |   1 +
 include/linux/hrtimer_api.h                 |   1 +
 include/linux/kobject_api.h                 |   1 +
 include/linux/kref_api.h                    |   1 +
 include/linux/ktime_api.h                   |   1 +
 include/linux/llist_api.h                   |   1 +
 include/linux/lockdep_api.h                 |   1 +
 include/linux/mm_api.h                      |   1 +
 include/linux/mutex_api.h                   |   1 +
 include/linux/perf_event_api.h              |   1 +
 include/linux/pgtable_api.h                 |   1 +
 include/linux/ptrace_api.h                  |   1 +
 include/linux/rcuwait_api.h                 |   1 +
 include/linux/refcount_api.h                |   1 +
 include/linux/sched/affinity.h              |   1 +
 include/linux/sched/cond_resched.h          |   1 +
 include/linux/sched/deadline.h              |   2 +
 include/linux/sched/posix-timers.h          |   1 +
 include/linux/sched/rseq_api.h              |   1 +
 include/linux/sched/task_flags.h            |   1 +
 include/linux/sched/thread_info_api.h       |   1 +
 include/linux/sched_clock.h                 |   2 +
 include/linux/seqlock_api.h                 |   1 +
 include/linux/softirq.h                     |   1 +
 include/linux/spinlock_api.h                |   1 +
 include/linux/swait_api.h                   |   1 +
 include/linux/syscalls_api.h                |   1 +
 include/linux/u64_stats_sync_api.h          |   1 +
 include/linux/wait_api.h                    |   1 +
 include/linux/workqueue_api.h               |   1 +
 kernel/sched/Makefile                       |  28 +++++-------
 kernel/sched/autogroup.c                    |   3 +-
 kernel/sched/autogroup.h                    |   5 +++
 kernel/sched/build_policy.c                 |  52 ++++++++++++++++++++++
 kernel/sched/build_utility.c                | 109 +++++++++++++++++++++++++++++++++++++++++++++
 kernel/sched/clock.c                        |  44 +++++++++----------
 kernel/sched/completion.c                   |   2 +-
 kernel/sched/core.c                         |  81 +++++++++++++++++++++++++++++-----
 kernel/sched/core_sched.c                   |   3 --
 kernel/sched/cpuacct.c                      |   3 +-
 kernel/sched/cpudeadline.c                  |   3 +-
 kernel/sched/cpufreq.c                      |   3 --
 kernel/sched/cpufreq_schedutil.c            |   7 ---
 kernel/sched/cpupri.c                       |   1 -
 kernel/sched/cputime.c                      |   1 -
 kernel/sched/deadline.c                     |   2 -
 kernel/sched/debug.c                        |   1 -
 kernel/sched/fair.c                         |  31 +++++++++++++
 kernel/sched/idle.c                         |   3 --
 kernel/sched/isolation.c                    |   1 -
 kernel/sched/loadavg.c                      |   1 -
 kernel/sched/membarrier.c                   |   1 -
 kernel/sched/pelt.c                         |   4 --
 kernel/sched/psi.c                          |  15 -------
 kernel/sched/rt.c                           |   3 --
 kernel/sched/sched.h                        | 114 ++++++++++++++++++++++++++----------------------
 kernel/sched/stats.c                        |   1 -
 kernel/sched/stats.h                        |   4 ++
 kernel/sched/stop_task.c                    |   1 -
 kernel/sched/swait.c                        |   1 -
 kernel/sched/topology.c                     |   1 -
 kernel/sched/wait.c                         |   1 -
 kernel/sched/wait_bit.c                     |   2 +-
 69 files changed, 407 insertions(+), 163 deletions(-)
 create mode 100644 arch/arm64/include/asm/paravirt_api_clock.h
 create mode 100644 arch/x86/include/asm/paravirt_api_clock.h
 create mode 100644 include/linux/cgroup_api.h
 create mode 100644 include/linux/cpumask_api.h
 create mode 100644 include/linux/fs_api.h
 create mode 100644 include/linux/gfp_api.h
 create mode 100644 include/linux/hashtable_api.h
 create mode 100644 include/linux/hrtimer_api.h
 create mode 100644 include/linux/kobject_api.h
 create mode 100644 include/linux/kref_api.h
 create mode 100644 include/linux/ktime_api.h
 create mode 100644 include/linux/llist_api.h
 create mode 100644 include/linux/lockdep_api.h
 create mode 100644 include/linux/mm_api.h
 create mode 100644 include/linux/mutex_api.h
 create mode 100644 include/linux/perf_event_api.h
 create mode 100644 include/linux/pgtable_api.h
 create mode 100644 include/linux/ptrace_api.h
 create mode 100644 include/linux/rcuwait_api.h
 create mode 100644 include/linux/refcount_api.h
 create mode 100644 include/linux/sched/affinity.h
 create mode 100644 include/linux/sched/cond_resched.h
 create mode 100644 include/linux/sched/posix-timers.h
 create mode 100644 include/linux/sched/rseq_api.h
 create mode 100644 include/linux/sched/task_flags.h
 create mode 100644 include/linux/sched/thread_info_api.h
 create mode 100644 include/linux/seqlock_api.h
 create mode 100644 include/linux/softirq.h
 create mode 100644 include/linux/spinlock_api.h
 create mode 100644 include/linux/swait_api.h
 create mode 100644 include/linux/syscalls_api.h
 create mode 100644 include/linux/u64_stats_sync_api.h
 create mode 100644 include/linux/wait_api.h
 create mode 100644 include/linux/workqueue_api.h
 create mode 100644 kernel/sched/build_policy.c
 create mode 100644 kernel/sched/build_utility.c

-- 
2.32.0

[PATCH 01/15] sched/headers: Fix header to build standalone: <linux/sched_clock.h>

[Ingo Molnar]

Uses various kernel types that don't build standalone.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
---
 include/linux/sched_clock.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/sched_clock.h b/include/linux/sched_clock.h
index 835ee87ed792..cb41c5edb4d4 100644
--- a/include/linux/sched_clock.h
+++ b/include/linux/sched_clock.h
@@ -5,6 +5,8 @@
 #ifndef LINUX_SCHED_CLOCK
 #define LINUX_SCHED_CLOCK
 
+#include <linux/types.h>
+
 #ifdef CONFIG_GENERIC_SCHED_CLOCK
 /**
  * struct clock_read_data - data required to read from sched_clock()
-- 
2.32.0

[PATCH 02/15] sched/headers: Add header guard to kernel/sched/sched.h

[Ingo Molnar]

Use the canonical header guard naming of the full path to the header.

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

diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 3da5718cd641..eab4a18f71c2 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -2,6 +2,9 @@
 /*
  * Scheduler internal types and methods:
  */
+#ifndef _KERNEL_SCHED_SCHED_H
+#define _KERNEL_SCHED_SCHED_H
+
 #include <linux/sched.h>
 
 #include <linux/sched/autogroup.h>
@@ -3137,3 +3140,4 @@ extern int sched_dynamic_mode(const char *str);
 extern void sched_dynamic_update(int mode);
 #endif
 
+#endif /* _KERNEL_SCHED_SCHED_H */
-- 
2.32.0

[PATCH 03/15] sched/headers: Add header guard to kernel/sched/stats.h and kernel/sched/autogroup.h

[Ingo Molnar]

Protect against multiple inclusion.

Also include "sched.h" in "stat.h", as it relies on it.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
---
 kernel/sched/autogroup.h | 5 +++++
 kernel/sched/stats.h     | 6 ++++++
 2 files changed, 11 insertions(+)

diff --git a/kernel/sched/autogroup.h b/kernel/sched/autogroup.h
index 90fcbfdd70c3..90d69f2c5eaf 100644
--- a/kernel/sched/autogroup.h
+++ b/kernel/sched/autogroup.h
@@ -1,4 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _KERNEL_SCHED_AUTOGROUP_H
+#define _KERNEL_SCHED_AUTOGROUP_H
+
 #ifdef CONFIG_SCHED_AUTOGROUP
 
 struct autogroup {
@@ -59,3 +62,5 @@ static inline int autogroup_path(struct task_group *tg, char *buf, int buflen)
 }
 
 #endif /* CONFIG_SCHED_AUTOGROUP */
+
+#endif /* _KERNEL_SCHED_AUTOGROUP_H */
diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h
index 3a3c826dd83a..edc0d13fc61b 100644
--- a/kernel/sched/stats.h
+++ b/kernel/sched/stats.h
@@ -1,7 +1,11 @@
 /* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _KERNEL_STATS_H
+#define _KERNEL_STATS_H
 
 #ifdef CONFIG_SCHEDSTATS
 
+#include "sched.h"
+
 extern struct static_key_false sched_schedstats;
 
 /*
@@ -298,3 +302,5 @@ sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *n
 # define sched_info_dequeue(rq, t)	do { } while (0)
 # define sched_info_switch(rq, t, next)	do { } while (0)
 #endif /* CONFIG_SCHED_INFO */
+
+#endif /* _KERNEL_STATS_H */
-- 
2.32.0

[PATCH 04/15] sched/headers: sched/clock: Mark all functions 'notrace', remove CC_FLAGS_FTRACE build asymmetry

[Ingo Molnar]

Mark all non-init functions in kernel/sched.c as 'notrace', instead of
turning them all off via CC_FLAGS_FTRACE.

This is going to allow the treatment of this file as any other scheduler
file, and it can be #include-ed in compound compilation units as well.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
---
 kernel/sched/Makefile |  3 ---
 kernel/sched/clock.c  | 42 +++++++++++++++++++++---------------------
 2 files changed, 21 insertions(+), 24 deletions(-)

diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
index c83b37af155b..c0c52026ad0d 100644
--- a/kernel/sched/Makefile
+++ b/kernel/sched/Makefile
@@ -1,7 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
-ifdef CONFIG_FUNCTION_TRACER
-CFLAGS_REMOVE_clock.o = $(CC_FLAGS_FTRACE)
-endif
 
 # The compilers are complaining about unused variables inside an if(0) scope
 # block. This is daft, shut them up.
diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c
index c2b2859ddd82..540d0e50e31c 100644
--- a/kernel/sched/clock.c
+++ b/kernel/sched/clock.c
@@ -61,7 +61,7 @@
  * This is default implementation.
  * Architectures and sub-architectures can override this.
  */
-unsigned long long __weak sched_clock(void)
+notrace unsigned long long __weak sched_clock(void)
 {
 	return (unsigned long long)(jiffies - INITIAL_JIFFIES)
 					* (NSEC_PER_SEC / HZ);
@@ -95,28 +95,28 @@ struct sched_clock_data {
 
 static DEFINE_PER_CPU_SHARED_ALIGNED(struct sched_clock_data, sched_clock_data);
 
-static inline struct sched_clock_data *this_scd(void)
+notrace static inline struct sched_clock_data *this_scd(void)
 {
 	return this_cpu_ptr(&sched_clock_data);
 }
 
-static inline struct sched_clock_data *cpu_sdc(int cpu)
+notrace static inline struct sched_clock_data *cpu_sdc(int cpu)
 {
 	return &per_cpu(sched_clock_data, cpu);
 }
 
-int sched_clock_stable(void)
+notrace int sched_clock_stable(void)
 {
 	return static_branch_likely(&__sched_clock_stable);
 }
 
-static void __scd_stamp(struct sched_clock_data *scd)
+notrace static void __scd_stamp(struct sched_clock_data *scd)
 {
 	scd->tick_gtod = ktime_get_ns();
 	scd->tick_raw = sched_clock();
 }
 
-static void __set_sched_clock_stable(void)
+notrace static void __set_sched_clock_stable(void)
 {
 	struct sched_clock_data *scd;
 
@@ -151,7 +151,7 @@ static void __set_sched_clock_stable(void)
  * The only way to fully avoid random clock jumps is to boot with:
  * "tsc=unstable".
  */
-static void __sched_clock_work(struct work_struct *work)
+notrace static void __sched_clock_work(struct work_struct *work)
 {
 	struct sched_clock_data *scd;
 	int cpu;
@@ -177,7 +177,7 @@ static void __sched_clock_work(struct work_struct *work)
 
 static DECLARE_WORK(sched_clock_work, __sched_clock_work);
 
-static void __clear_sched_clock_stable(void)
+notrace static void __clear_sched_clock_stable(void)
 {
 	if (!sched_clock_stable())
 		return;
@@ -186,7 +186,7 @@ static void __clear_sched_clock_stable(void)
 	schedule_work(&sched_clock_work);
 }
 
-void clear_sched_clock_stable(void)
+notrace void clear_sched_clock_stable(void)
 {
 	__sched_clock_stable_early = 0;
 
@@ -196,7 +196,7 @@ void clear_sched_clock_stable(void)
 		__clear_sched_clock_stable();
 }
 
-static void __sched_clock_gtod_offset(void)
+notrace static void __sched_clock_gtod_offset(void)
 {
 	struct sched_clock_data *scd = this_scd();
 
@@ -246,12 +246,12 @@ late_initcall(sched_clock_init_late);
  * min, max except they take wrapping into account
  */
 
-static inline u64 wrap_min(u64 x, u64 y)
+notrace static inline u64 wrap_min(u64 x, u64 y)
 {
 	return (s64)(x - y) < 0 ? x : y;
 }
 
-static inline u64 wrap_max(u64 x, u64 y)
+notrace static inline u64 wrap_max(u64 x, u64 y)
 {
 	return (s64)(x - y) > 0 ? x : y;
 }
@@ -262,7 +262,7 @@ static inline u64 wrap_max(u64 x, u64 y)
  *  - filter out backward motion
  *  - use the GTOD tick value to create a window to filter crazy TSC values
  */
-static u64 sched_clock_local(struct sched_clock_data *scd)
+notrace static u64 sched_clock_local(struct sched_clock_data *scd)
 {
 	u64 now, clock, old_clock, min_clock, max_clock, gtod;
 	s64 delta;
@@ -295,7 +295,7 @@ static u64 sched_clock_local(struct sched_clock_data *scd)
 	return clock;
 }
 
-static u64 sched_clock_remote(struct sched_clock_data *scd)
+notrace static u64 sched_clock_remote(struct sched_clock_data *scd)
 {
 	struct sched_clock_data *my_scd = this_scd();
 	u64 this_clock, remote_clock;
@@ -362,7 +362,7 @@ static u64 sched_clock_remote(struct sched_clock_data *scd)
  *
  * See cpu_clock().
  */
-u64 sched_clock_cpu(int cpu)
+notrace u64 sched_clock_cpu(int cpu)
 {
 	struct sched_clock_data *scd;
 	u64 clock;
@@ -386,7 +386,7 @@ u64 sched_clock_cpu(int cpu)
 }
 EXPORT_SYMBOL_GPL(sched_clock_cpu);
 
-void sched_clock_tick(void)
+notrace void sched_clock_tick(void)
 {
 	struct sched_clock_data *scd;
 
@@ -403,7 +403,7 @@ void sched_clock_tick(void)
 	sched_clock_local(scd);
 }
 
-void sched_clock_tick_stable(void)
+notrace void sched_clock_tick_stable(void)
 {
 	if (!sched_clock_stable())
 		return;
@@ -423,7 +423,7 @@ void sched_clock_tick_stable(void)
 /*
  * We are going deep-idle (irqs are disabled):
  */
-void sched_clock_idle_sleep_event(void)
+notrace void sched_clock_idle_sleep_event(void)
 {
 	sched_clock_cpu(smp_processor_id());
 }
@@ -432,7 +432,7 @@ EXPORT_SYMBOL_GPL(sched_clock_idle_sleep_event);
 /*
  * We just idled; resync with ktime.
  */
-void sched_clock_idle_wakeup_event(void)
+notrace void sched_clock_idle_wakeup_event(void)
 {
 	unsigned long flags;
 
@@ -458,7 +458,7 @@ void __init sched_clock_init(void)
 	local_irq_enable();
 }
 
-u64 sched_clock_cpu(int cpu)
+notrace u64 sched_clock_cpu(int cpu)
 {
 	if (!static_branch_likely(&sched_clock_running))
 		return 0;
@@ -476,7 +476,7 @@ u64 sched_clock_cpu(int cpu)
  * On bare metal this function should return the same as local_clock.
  * Architectures and sub-architectures can override this.
  */
-u64 __weak running_clock(void)
+notrace u64 __weak running_clock(void)
 {
 	return local_clock();
 }
-- 
2.32.0

[PATCH 05/15] sched/headers: Add initial new headers as identity mappings

[Ingo Molnar]

This allows code sharing between fast-headers tree and the vanilla
scheduler tree.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
---
 arch/arm64/include/asm/paravirt_api_clock.h | 1 +
 arch/x86/include/asm/paravirt_api_clock.h   | 1 +
 include/linux/cgroup_api.h                  | 1 +
 include/linux/cpumask_api.h                 | 1 +
 include/linux/fs_api.h                      | 1 +
 include/linux/gfp_api.h                     | 1 +
 include/linux/hashtable_api.h               | 1 +
 include/linux/hrtimer_api.h                 | 1 +
 include/linux/kobject_api.h                 | 1 +
 include/linux/kref_api.h                    | 1 +
 include/linux/ktime_api.h                   | 1 +
 include/linux/llist_api.h                   | 1 +
 include/linux/lockdep_api.h                 | 1 +
 include/linux/mm_api.h                      | 1 +
 include/linux/mutex_api.h                   | 1 +
 include/linux/perf_event_api.h              | 1 +
 include/linux/pgtable_api.h                 | 1 +
 include/linux/ptrace_api.h                  | 1 +
 include/linux/rcuwait_api.h                 | 1 +
 include/linux/refcount_api.h                | 1 +
 include/linux/sched/affinity.h              | 1 +
 include/linux/sched/cond_resched.h          | 1 +
 include/linux/sched/posix-timers.h          | 1 +
 include/linux/sched/rseq_api.h              | 1 +
 include/linux/sched/task_flags.h            | 1 +
 include/linux/sched/thread_info_api.h       | 1 +
 include/linux/seqlock_api.h                 | 1 +
 include/linux/softirq.h                     | 1 +
 include/linux/spinlock_api.h                | 1 +
 include/linux/swait_api.h                   | 1 +
 include/linux/syscalls_api.h                | 1 +
 include/linux/u64_stats_sync_api.h          | 1 +
 include/linux/wait_api.h                    | 1 +
 include/linux/workqueue_api.h               | 1 +
 34 files changed, 34 insertions(+)

diff --git a/arch/arm64/include/asm/paravirt_api_clock.h b/arch/arm64/include/asm/paravirt_api_clock.h
new file mode 100644
index 000000000000..65ac7cee0dad
--- /dev/null
+++ b/arch/arm64/include/asm/paravirt_api_clock.h
@@ -0,0 +1 @@
+#include <asm/paravirt.h>
diff --git a/arch/x86/include/asm/paravirt_api_clock.h b/arch/x86/include/asm/paravirt_api_clock.h
new file mode 100644
index 000000000000..65ac7cee0dad
--- /dev/null
+++ b/arch/x86/include/asm/paravirt_api_clock.h
@@ -0,0 +1 @@
+#include <asm/paravirt.h>
diff --git a/include/linux/cgroup_api.h b/include/linux/cgroup_api.h
new file mode 100644
index 000000000000..d0cfe8025111
--- /dev/null
+++ b/include/linux/cgroup_api.h
@@ -0,0 +1 @@
+#include <linux/cgroup.h>
diff --git a/include/linux/cpumask_api.h b/include/linux/cpumask_api.h
new file mode 100644
index 000000000000..83bd3ebe82b0
--- /dev/null
+++ b/include/linux/cpumask_api.h
@@ -0,0 +1 @@
+#include <linux/cpumask.h>
diff --git a/include/linux/fs_api.h b/include/linux/fs_api.h
new file mode 100644
index 000000000000..83be38d6d413
--- /dev/null
+++ b/include/linux/fs_api.h
@@ -0,0 +1 @@
+#include <linux/fs.h>
diff --git a/include/linux/gfp_api.h b/include/linux/gfp_api.h
new file mode 100644
index 000000000000..5a05a2764a86
--- /dev/null
+++ b/include/linux/gfp_api.h
@@ -0,0 +1 @@
+#include <linux/gfp.h>
diff --git a/include/linux/hashtable_api.h b/include/linux/hashtable_api.h
new file mode 100644
index 000000000000..c268ac2c5c0e
--- /dev/null
+++ b/include/linux/hashtable_api.h
@@ -0,0 +1 @@
+#include <linux/hashtable.h>
diff --git a/include/linux/hrtimer_api.h b/include/linux/hrtimer_api.h
new file mode 100644
index 000000000000..8d9700894468
--- /dev/null
+++ b/include/linux/hrtimer_api.h
@@ -0,0 +1 @@
+#include <linux/hrtimer.h>
diff --git a/include/linux/kobject_api.h b/include/linux/kobject_api.h
new file mode 100644
index 000000000000..6e36a054c2d6
--- /dev/null
+++ b/include/linux/kobject_api.h
@@ -0,0 +1 @@
+#include <linux/kobject.h>
diff --git a/include/linux/kref_api.h b/include/linux/kref_api.h
new file mode 100644
index 000000000000..d67e554721d2
--- /dev/null
+++ b/include/linux/kref_api.h
@@ -0,0 +1 @@
+#include <linux/kref.h>
diff --git a/include/linux/ktime_api.h b/include/linux/ktime_api.h
new file mode 100644
index 000000000000..f697d493960f
--- /dev/null
+++ b/include/linux/ktime_api.h
@@ -0,0 +1 @@
+#include <linux/ktime.h>
diff --git a/include/linux/llist_api.h b/include/linux/llist_api.h
new file mode 100644
index 000000000000..625bec0393a1
--- /dev/null
+++ b/include/linux/llist_api.h
@@ -0,0 +1 @@
+#include <linux/llist.h>
diff --git a/include/linux/lockdep_api.h b/include/linux/lockdep_api.h
new file mode 100644
index 000000000000..907e66979ab2
--- /dev/null
+++ b/include/linux/lockdep_api.h
@@ -0,0 +1 @@
+#include <linux/lockdep.h>
diff --git a/include/linux/mm_api.h b/include/linux/mm_api.h
new file mode 100644
index 000000000000..a5ace2b198b8
--- /dev/null
+++ b/include/linux/mm_api.h
@@ -0,0 +1 @@
+#include <linux/mm.h>
diff --git a/include/linux/mutex_api.h b/include/linux/mutex_api.h
new file mode 100644
index 000000000000..85ab9491e13e
--- /dev/null
+++ b/include/linux/mutex_api.h
@@ -0,0 +1 @@
+#include <linux/mutex.h>
diff --git a/include/linux/perf_event_api.h b/include/linux/perf_event_api.h
new file mode 100644
index 000000000000..c2fd6048b790
--- /dev/null
+++ b/include/linux/perf_event_api.h
@@ -0,0 +1 @@
+#include <linux/perf_event.h>
diff --git a/include/linux/pgtable_api.h b/include/linux/pgtable_api.h
new file mode 100644
index 000000000000..ff367a4ba8c4
--- /dev/null
+++ b/include/linux/pgtable_api.h
@@ -0,0 +1 @@
+#include <linux/pgtable.h>
diff --git a/include/linux/ptrace_api.h b/include/linux/ptrace_api.h
new file mode 100644
index 000000000000..26e7d275ad8d
--- /dev/null
+++ b/include/linux/ptrace_api.h
@@ -0,0 +1 @@
+#include <linux/ptrace.h>
diff --git a/include/linux/rcuwait_api.h b/include/linux/rcuwait_api.h
new file mode 100644
index 000000000000..f962e28544dd
--- /dev/null
+++ b/include/linux/rcuwait_api.h
@@ -0,0 +1 @@
+#include <linux/rcuwait.h>
diff --git a/include/linux/refcount_api.h b/include/linux/refcount_api.h
new file mode 100644
index 000000000000..5f032589f568
--- /dev/null
+++ b/include/linux/refcount_api.h
@@ -0,0 +1 @@
+#include <linux/refcount.h>
diff --git a/include/linux/sched/affinity.h b/include/linux/sched/affinity.h
new file mode 100644
index 000000000000..227f5be81bcd
--- /dev/null
+++ b/include/linux/sched/affinity.h
@@ -0,0 +1 @@
+#include <linux/sched.h>
diff --git a/include/linux/sched/cond_resched.h b/include/linux/sched/cond_resched.h
new file mode 100644
index 000000000000..227f5be81bcd
--- /dev/null
+++ b/include/linux/sched/cond_resched.h
@@ -0,0 +1 @@
+#include <linux/sched.h>
diff --git a/include/linux/sched/posix-timers.h b/include/linux/sched/posix-timers.h
new file mode 100644
index 000000000000..523a381d6c88
--- /dev/null
+++ b/include/linux/sched/posix-timers.h
@@ -0,0 +1 @@
+#include <linux/posix-timers.h>
diff --git a/include/linux/sched/rseq_api.h b/include/linux/sched/rseq_api.h
new file mode 100644
index 000000000000..cf2af72693e1
--- /dev/null
+++ b/include/linux/sched/rseq_api.h
@@ -0,0 +1 @@
+#include <linux/rseq.h>
diff --git a/include/linux/sched/task_flags.h b/include/linux/sched/task_flags.h
new file mode 100644
index 000000000000..227f5be81bcd
--- /dev/null
+++ b/include/linux/sched/task_flags.h
@@ -0,0 +1 @@
+#include <linux/sched.h>
diff --git a/include/linux/sched/thread_info_api.h b/include/linux/sched/thread_info_api.h
new file mode 100644
index 000000000000..2c60fbc16c08
--- /dev/null
+++ b/include/linux/sched/thread_info_api.h
@@ -0,0 +1 @@
+#include <linux/thread_info.h>
diff --git a/include/linux/seqlock_api.h b/include/linux/seqlock_api.h
new file mode 100644
index 000000000000..be91e7d3b826
--- /dev/null
+++ b/include/linux/seqlock_api.h
@@ -0,0 +1 @@
+#include <linux/seqlock.h>
diff --git a/include/linux/softirq.h b/include/linux/softirq.h
new file mode 100644
index 000000000000..c73d7dcb4cb5
--- /dev/null
+++ b/include/linux/softirq.h
@@ -0,0 +1 @@
+#include <linux/interrupt.h>
diff --git a/include/linux/spinlock_api.h b/include/linux/spinlock_api.h
new file mode 100644
index 000000000000..6338b27f98df
--- /dev/null
+++ b/include/linux/spinlock_api.h
@@ -0,0 +1 @@
+#include <linux/spinlock.h>
diff --git a/include/linux/swait_api.h b/include/linux/swait_api.h
new file mode 100644
index 000000000000..1eeaaaaa5ea7
--- /dev/null
+++ b/include/linux/swait_api.h
@@ -0,0 +1 @@
+#include <linux/swait.h>
diff --git a/include/linux/syscalls_api.h b/include/linux/syscalls_api.h
new file mode 100644
index 000000000000..23e012b04db4
--- /dev/null
+++ b/include/linux/syscalls_api.h
@@ -0,0 +1 @@
+#include <linux/syscalls.h>
diff --git a/include/linux/u64_stats_sync_api.h b/include/linux/u64_stats_sync_api.h
new file mode 100644
index 000000000000..c72ca63da44b
--- /dev/null
+++ b/include/linux/u64_stats_sync_api.h
@@ -0,0 +1 @@
+#include <linux/u64_stats_sync.h>
diff --git a/include/linux/wait_api.h b/include/linux/wait_api.h
new file mode 100644
index 000000000000..4e930548935a
--- /dev/null
+++ b/include/linux/wait_api.h
@@ -0,0 +1 @@
+#include <linux/wait.h>
diff --git a/include/linux/workqueue_api.h b/include/linux/workqueue_api.h
new file mode 100644
index 000000000000..77debb5d2760
--- /dev/null
+++ b/include/linux/workqueue_api.h
@@ -0,0 +1 @@
+#include <linux/workqueue.h>
-- 
2.32.0

[PATCH 06/15] sched/headers: Fix comment typo in kernel/sched/cpudeadline.c

[Ingo Molnar]

File name changed.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
---
 kernel/sched/cpudeadline.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
index ceb03d76c0cc..0e196f0de492 100644
--- a/kernel/sched/cpudeadline.c
+++ b/kernel/sched/cpudeadline.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- *  kernel/sched/cpudl.c
+ *  kernel/sched/cpudeadline.c
  *
  *  Global CPU deadline management
  *
-- 
2.32.0

[PATCH 07/15] sched/headers: Make the <linux/sched/deadline.h> header build standalone

[Ingo Molnar]

This header depends on various scheduler definitions.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
---
 include/linux/sched/deadline.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/sched/deadline.h b/include/linux/sched/deadline.h
index 1aff00b65f3c..7c83d4d5a971 100644
--- a/include/linux/sched/deadline.h
+++ b/include/linux/sched/deadline.h
@@ -6,6 +6,8 @@
  * NORMAL/BATCH tasks.
  */
 
+#include <linux/sched.h>
+
 #define MAX_DL_PRIO		0
 
 static inline int dl_prio(int prio)
-- 
2.32.0

[PATCH 08/15] sched/headers: Introduce kernel/sched/build_utility.c and build multiple .c files there

[Ingo Molnar]

Collect all utility functionality source code files into a single kernel/sched/build_utility.c file,
via #include-ing the .c files:

    kernel/sched/clock.c
    kernel/sched/completion.c
    kernel/sched/loadavg.c
    kernel/sched/swait.c
    kernel/sched/wait_bit.c
    kernel/sched/wait.c

CONFIG_CPU_FREQ:
    kernel/sched/cpufreq.c

CONFIG_CPU_FREQ_GOV_SCHEDUTIL:
    kernel/sched/cpufreq_schedutil.c

CONFIG_CGROUP_CPUACCT:
    kernel/sched/cpuacct.c

CONFIG_SCHED_DEBUG:
    kernel/sched/debug.c

CONFIG_SCHEDSTATS:
    kernel/sched/stats.c

CONFIG_SMP:
   kernel/sched/cpupri.c
   kernel/sched/stop_task.c
   kernel/sched/topology.c

CONFIG_SCHED_CORE:
   kernel/sched/core_sched.c

CONFIG_PSI:
   kernel/sched/psi.c

CONFIG_MEMBARRIER:
   kernel/sched/membarrier.c

CONFIG_CPU_ISOLATION:
   kernel/sched/isolation.c

CONFIG_SCHED_AUTOGROUP:
   kernel/sched/autogroup.c

The goal is to amortize the 60+ KLOC header bloat from over a dozen build units into
a single build unit.

The build time of build_utility.c also roughly matches the build time of core.c and
fair.c - allowing better load-balancing of scheduler-only rebuilds.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
---
 kernel/sched/Makefile            | 25 +++++++++-------------
 kernel/sched/autogroup.c         |  3 +--
 kernel/sched/build_utility.c     | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 kernel/sched/clock.c             |  2 --
 kernel/sched/completion.c        |  2 +-
 kernel/sched/core_sched.c        |  3 ---
 kernel/sched/cpuacct.c           |  3 +--
 kernel/sched/cpufreq.c           |  3 ---
 kernel/sched/cpufreq_schedutil.c |  7 ------
 kernel/sched/cpupri.c            |  1 -
 kernel/sched/debug.c             |  1 -
 kernel/sched/isolation.c         |  1 -
 kernel/sched/loadavg.c           |  1 -
 kernel/sched/membarrier.c        |  1 -
 kernel/sched/psi.c               | 15 -------------
 kernel/sched/sched.h             | 57 +++++++++++++++++++++++++++++++++++++++++++++++--
 kernel/sched/stats.c             |  1 -
 kernel/sched/stop_task.c         |  1 -
 kernel/sched/swait.c             |  1 -
 kernel/sched/topology.c          |  1 -
 kernel/sched/wait.c              |  1 -
 kernel/sched/wait_bit.c          |  2 +-
 22 files changed, 139 insertions(+), 63 deletions(-)

diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
index c0c52026ad0d..4a4785cb3cd2 100644
--- a/kernel/sched/Makefile
+++ b/kernel/sched/Makefile
@@ -22,18 +22,13 @@ ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y)
 CFLAGS_core.o := $(PROFILING) -fno-omit-frame-pointer
 endif
 
-obj-y += core.o loadavg.o clock.o cputime.o
-obj-y += idle.o fair.o rt.o deadline.o
-obj-y += wait.o wait_bit.o swait.o completion.o
-
-obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o topology.o stop_task.o pelt.o
-obj-$(CONFIG_SCHED_AUTOGROUP) += autogroup.o
-obj-$(CONFIG_SCHEDSTATS) += stats.o
-obj-$(CONFIG_SCHED_DEBUG) += debug.o
-obj-$(CONFIG_CGROUP_CPUACCT) += cpuacct.o
-obj-$(CONFIG_CPU_FREQ) += cpufreq.o
-obj-$(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) += cpufreq_schedutil.o
-obj-$(CONFIG_MEMBARRIER) += membarrier.o
-obj-$(CONFIG_CPU_ISOLATION) += isolation.o
-obj-$(CONFIG_PSI) += psi.o
-obj-$(CONFIG_SCHED_CORE) += core_sched.o
+#
+# Build efficiency:
+#
+# These compilation units have roughly the same size and complexity - so their
+# build parallelizes well and finishes roughly at once:
+#
+obj-y += core.o
+obj-y += fair.o
+obj-y += build_utility.o
+obj-y += idle.o rt.o deadline.o cputime.o cpudeadline.o pelt.o
diff --git a/kernel/sched/autogroup.c b/kernel/sched/autogroup.c
index 31dd2593145e..16092b49ff6a 100644
--- a/kernel/sched/autogroup.c
+++ b/kernel/sched/autogroup.c
@@ -1,9 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0
+
 /*
  * Auto-group scheduling implementation:
  */
-#include <linux/nospec.h>
-#include "sched.h"
 
 unsigned int __read_mostly sysctl_sched_autogroup_enabled = 1;
 static struct autogroup autogroup_default;
diff --git a/kernel/sched/build_utility.c b/kernel/sched/build_utility.c
new file mode 100644
index 000000000000..31216ce0b4b3
--- /dev/null
+++ b/kernel/sched/build_utility.c
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * These are various utility functions of the scheduler,
+ * built in a single compilation unit for build efficiency reasons.
+ *
+ * ( Incidentally, the size of the compilation unit is roughly
+ *   comparable to core.c, fair.c, smp.c and policy.c, the other
+ *   big compilation units. This helps balance build time, while
+ *   coalescing source files to amortize header inclusion
+ *   cost. )
+ */
+
+#include "sched.h"
+#include "sched-pelt.h"
+
+#include <linux/sched_clock.h>
+
+#include "clock.c"
+
+#ifdef CONFIG_CGROUP_CPUACCT
+# include "cpuacct.c"
+#endif
+
+#ifdef CONFIG_CPU_FREQ
+# include "cpufreq.c"
+#endif
+
+#ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL
+# include "cpufreq_schedutil.c"
+#endif
+
+#ifdef CONFIG_SCHED_DEBUG
+# include "debug.c"
+#endif
+
+#ifdef CONFIG_SCHEDSTATS
+# include "stats.c"
+#endif
+
+#include "loadavg.c"
+#include "completion.c"
+#include "swait.c"
+#include "wait_bit.c"
+#include "wait.c"
+
+#ifdef CONFIG_SMP
+# include "cpupri.c"
+# include "stop_task.c"
+# include "topology.c"
+#endif
+
+#ifdef CONFIG_SCHED_CORE
+# include "core_sched.c"
+#endif
+
+#ifdef CONFIG_PSI
+# include "psi.c"
+#endif
+
+#ifdef CONFIG_MEMBARRIER
+# include "membarrier.c"
+#endif
+
+#ifdef CONFIG_CPU_ISOLATION
+# include "isolation.c"
+#endif
+
+#ifdef CONFIG_SCHED_AUTOGROUP
+# include "autogroup.c"
+#endif
diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c
index 540d0e50e31c..d9272d9061a3 100644
--- a/kernel/sched/clock.c
+++ b/kernel/sched/clock.c
@@ -53,8 +53,6 @@
  * that is otherwise invisible (TSC gets stopped).
  *
  */
-#include "sched.h"
-#include <linux/sched_clock.h>
 
 /*
  * Scheduler clock - returns current time in nanosec units.
diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c
index a778554f9dad..35f15c26ed54 100644
--- a/kernel/sched/completion.c
+++ b/kernel/sched/completion.c
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
+
 /*
  * Generic wait-for-completion handler;
  *
@@ -11,7 +12,6 @@
  * typically be used for exclusion which gives rise to priority inversion.
  * Waiting for completion is a typically sync point, but not an exclusion point.
  */
-#include "sched.h"
 
 /**
  * complete: - signals a single thread waiting on this completion
diff --git a/kernel/sched/core_sched.c b/kernel/sched/core_sched.c
index c8746a9a7ada..38a2cec21014 100644
--- a/kernel/sched/core_sched.c
+++ b/kernel/sched/core_sched.c
@@ -1,8 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-only
 
-#include <linux/prctl.h>
-#include "sched.h"
-
 /*
  * A simple wrapper around refcount. An allocated sched_core_cookie's
  * address is used to compute the cookie of the task.
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index 3d06c5e4220d..2c505cf800aa 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -1,12 +1,11 @@
 // SPDX-License-Identifier: GPL-2.0
+
 /*
  * CPU accounting code for task groups.
  *
  * Based on the work by Paul Menage (menage@google.com) and Balbir Singh
  * (balbir@in.ibm.com).
  */
-#include <asm/irq_regs.h>
-#include "sched.h"
 
 /* Time spent by the tasks of the CPU accounting group executing in ... */
 enum cpuacct_stat_index {
diff --git a/kernel/sched/cpufreq.c b/kernel/sched/cpufreq.c
index 7c2fe50fd76d..5252fb191fae 100644
--- a/kernel/sched/cpufreq.c
+++ b/kernel/sched/cpufreq.c
@@ -5,9 +5,6 @@
  * Copyright (C) 2016, Intel Corporation
  * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  */
-#include <linux/cpufreq.h>
-
-#include "sched.h"
 
 DEFINE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data);
 
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index 6d65ab6e484e..f68885d049f2 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -6,13 +6,6 @@
  * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  */
 
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include "sched.h"
-
-#include <linux/sched/cpufreq.h>
-#include <trace/events/power.h>
-
 #define IOWAIT_BOOST_MIN	(SCHED_CAPACITY_SCALE / 8)
 
 struct sugov_tunables {
diff --git a/kernel/sched/cpupri.c b/kernel/sched/cpupri.c
index d583f2aa744e..fa9ce9d83683 100644
--- a/kernel/sched/cpupri.c
+++ b/kernel/sched/cpupri.c
@@ -22,7 +22,6 @@
  *  worst case complexity of O(min(101, nr_domcpus)), though the scenario that
  *  yields the worst case search is fairly contrived.
  */
-#include "sched.h"
 
 /*
  * p->rt_priority   p->prio   newpri   cpupri
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 102d6f70e84d..bb3d63bdf4ae 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -6,7 +6,6 @@
  *
  * Copyright(C) 2007, Red Hat, Inc., Ingo Molnar
  */
-#include "sched.h"
 
 /*
  * This allows printing both to /proc/sched_debug and
diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c
index b4d10815c45a..373d42c707bc 100644
--- a/kernel/sched/isolation.c
+++ b/kernel/sched/isolation.c
@@ -7,7 +7,6 @@
  * Copyright (C) 2017-2018 SUSE, Frederic Weisbecker
  *
  */
-#include "sched.h"
 
 enum hk_flags {
 	HK_FLAG_TIMER		= BIT(HK_TYPE_TIMER),
diff --git a/kernel/sched/loadavg.c b/kernel/sched/loadavg.c
index 954b229868d9..52c8f8226b0d 100644
--- a/kernel/sched/loadavg.c
+++ b/kernel/sched/loadavg.c
@@ -6,7 +6,6 @@
  * figure. Its a silly number but people think its important. We go through
  * great pains to make it work on big machines and tickless kernels.
  */
-#include "sched.h"
 
 /*
  * Global load-average calculations
diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c
index 3d2825408e3a..0c5be7ebb1dc 100644
--- a/kernel/sched/membarrier.c
+++ b/kernel/sched/membarrier.c
@@ -4,7 +4,6 @@
  *
  * membarrier system call
  */
-#include "sched.h"
 
 /*
  * For documentation purposes, here are some membarrier ordering
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index 8fb08a12f602..a4fa3aadfcba 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -137,21 +137,6 @@
  * sampling of the aggregate task states would be.
  */
 
-#include "../workqueue_internal.h"
-#include <linux/sched/loadavg.h>
-#include <linux/seq_file.h>
-#include <linux/proc_fs.h>
-#include <linux/seqlock.h>
-#include <linux/uaccess.h>
-#include <linux/cgroup.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/ctype.h>
-#include <linux/file.h>
-#include <linux/poll.h>
-#include <linux/psi.h>
-#include "sched.h"
-
 static int psi_bug __read_mostly;
 
 DEFINE_STATIC_KEY_FALSE(psi_disabled);
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index eab4a18f71c2..79c7a8a2be65 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -6,7 +6,25 @@
 #define _KERNEL_SCHED_SCHED_H
 
 #include <linux/sched.h>
+#include <linux/cpumask.h>
+#include <linux/ktime_api.h>
+#include <linux/cgroup_api.h>
+#include <linux/topology.h>
+#include <linux/prctl.h>
+#include <linux/ptrace_api.h>
+#include <linux/gfp_api.h>
+#include <linux/sched/clock.h>
+#include <linux/workqueue_api.h>
+#include <linux/tick.h>
+#include <linux/ktime_api.h>
+#include <linux/swait_api.h>
+#include <linux/hashtable_api.h>
+#include <linux/cpufreq.h>
+#include <linux/utsname.h>
 
+#include <asm/irq_regs.h>
+
+#include <linux/sched/affinity.h>
 #include <linux/sched/autogroup.h>
 #include <linux/sched/clock.h>
 #include <linux/sched/coredump.h>
@@ -24,6 +42,7 @@
 #include <linux/sched/nohz.h>
 #include <linux/sched/numa_balancing.h>
 #include <linux/sched/prio.h>
+#include <linux/sched/rseq_api.h>
 #include <linux/sched/rt.h>
 #include <linux/sched/signal.h>
 #include <linux/sched/smt.h>
@@ -31,6 +50,7 @@
 #include <linux/sched/sysctl.h>
 #include <linux/sched/task.h>
 #include <linux/sched/task_stack.h>
+#include <linux/sched/thread_info_api.h>
 #include <linux/sched/topology.h>
 #include <linux/sched/user.h>
 #include <linux/sched/wake_q.h>
@@ -69,8 +89,7 @@
 #include <linux/syscalls.h>
 #include <linux/task_work.h>
 #include <linux/tsacct_kern.h>
-
-#include <asm/tlb.h>
+#include <linux/hrtimer_api.h>
 
 #ifdef CONFIG_PARAVIRT
 # include <asm/paravirt.h>
@@ -87,6 +106,40 @@
 # define SCHED_WARN_ON(x)	({ (void)(x), 0; })
 #endif
 
+#include <linux/bitmap.h>
+#include <linux/capability.h>
+#include <linux/cgroup.h>
+#include <linux/cpufreq.h>
+#include <linux/cpumask_api.h>
+#include <linux/ctype.h>
+#include <linux/file.h>
+#include <linux/jiffies.h>
+#include <linux/kref_api.h>
+#include <linux/lockdep_api.h>
+#include <linux/module.h>
+#include <linux/mutex_api.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+#include <linux/psi.h>
+#include <linux/sched/affinity.h>
+#include <linux/sched.h>
+#include <linux/sched/loadavg.h>
+#include <linux/sched/mm.h>
+#include <linux/sched/rseq_api.h>
+#include <linux/seq_file.h>
+#include <linux/seqlock.h>
+#include <linux/syscalls_api.h>
+#include <linux/syscalls.h>
+#include <linux/topology.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/wait_api.h>
+#include <linux/workqueue_api.h>
+
+#include <trace/events/power.h>
+
+#include "../workqueue_internal.h"
+
 struct rq;
 struct cpuidle_state;
 
diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c
index 07dde2928c79..857f837f52cb 100644
--- a/kernel/sched/stats.c
+++ b/kernel/sched/stats.c
@@ -2,7 +2,6 @@
 /*
  * /proc/schedstat implementation
  */
-#include "sched.h"
 
 void __update_stats_wait_start(struct rq *rq, struct task_struct *p,
 			       struct sched_statistics *stats)
diff --git a/kernel/sched/stop_task.c b/kernel/sched/stop_task.c
index 0b165a25f22f..d04073a93eb4 100644
--- a/kernel/sched/stop_task.c
+++ b/kernel/sched/stop_task.c
@@ -7,7 +7,6 @@
  *
  * See kernel/stop_machine.c
  */
-#include "sched.h"
 
 #ifdef CONFIG_SMP
 static int
diff --git a/kernel/sched/swait.c b/kernel/sched/swait.c
index e1c655f928c7..76b9b796e695 100644
--- a/kernel/sched/swait.c
+++ b/kernel/sched/swait.c
@@ -2,7 +2,6 @@
 /*
  * <linux/swait.h> (simple wait queues ) implementation:
  */
-#include "sched.h"
 
 void __init_swait_queue_head(struct swait_queue_head *q, const char *name,
 			     struct lock_class_key *key)
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 32841c6741d1..e8af72fd70bd 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -2,7 +2,6 @@
 /*
  * Scheduler topology setup/handling methods
  */
-#include "sched.h"
 
 DEFINE_MUTEX(sched_domains_mutex);
 
diff --git a/kernel/sched/wait.c b/kernel/sched/wait.c
index eca38107b32f..9860bb9a847c 100644
--- a/kernel/sched/wait.c
+++ b/kernel/sched/wait.c
@@ -4,7 +4,6 @@
  *
  * (C) 2004 Nadia Yvette Chambers, Oracle
  */
-#include "sched.h"
 
 void __init_waitqueue_head(struct wait_queue_head *wq_head, const char *name, struct lock_class_key *key)
 {
diff --git a/kernel/sched/wait_bit.c b/kernel/sched/wait_bit.c
index 02ce292b9bc0..d4788f810b55 100644
--- a/kernel/sched/wait_bit.c
+++ b/kernel/sched/wait_bit.c
@@ -1,8 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0-only
+
 /*
  * The implementation of the wait_bit*() and related waiting APIs:
  */
-#include "sched.h"
 
 #define WAIT_TABLE_BITS 8
 #define WAIT_TABLE_SIZE (1 << WAIT_TABLE_BITS)
-- 
2.32.0

[PATCH 09/15] sched/headers: Introduce kernel/sched/build_policy.c and build multiple .c files there

[Ingo Molnar]

Similarly to kernel/sched/build_utility.c, collect all 'scheduling policy' related
source code files into kernel/sched/build_policy.c:

    kernel/sched/idle.c

    kernel/sched/rt.c

    kernel/sched/cpudeadline.c
    kernel/sched/pelt.c

    kernel/sched/cputime.c
    kernel/sched/deadline.c

With the exception of fair.c, which we continue to build as a separate file
for build efficiency and parallelism reasons.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
---
 kernel/sched/Makefile       |  2 +-
 kernel/sched/build_policy.c | 29 +++++++++++++++++++++++++++++
 kernel/sched/cpudeadline.c  |  1 -
 kernel/sched/cputime.c      |  1 -
 kernel/sched/deadline.c     |  2 --
 kernel/sched/idle.c         |  3 ---
 kernel/sched/pelt.c         |  4 ----
 kernel/sched/rt.c           |  3 ---
 kernel/sched/sched.h        |  8 ++++++++
 9 files changed, 38 insertions(+), 15 deletions(-)

diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
index 4a4785cb3cd2..976092b7bd45 100644
--- a/kernel/sched/Makefile
+++ b/kernel/sched/Makefile
@@ -30,5 +30,5 @@ endif
 #
 obj-y += core.o
 obj-y += fair.o
+obj-y += build_policy.o
 obj-y += build_utility.o
-obj-y += idle.o rt.o deadline.o cputime.o cpudeadline.o pelt.o
diff --git a/kernel/sched/build_policy.c b/kernel/sched/build_policy.c
new file mode 100644
index 000000000000..6bb384ddcfab
--- /dev/null
+++ b/kernel/sched/build_policy.c
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * These are the scheduling policy related scheduler files, built
+ * in a single compilation unit for build efficiency reasons.
+ *
+ * ( Incidentally, the size of the compilation unit is roughly
+ *   comparable to core.c and fair.c, the other two big
+ *   compilation units. This helps balance build time, while
+ *   coalescing source files to amortize header inclusion
+ *   cost. )
+ *
+ * core.c and fair.c are built separately.
+ */
+
+#include "sched.h"
+#include "pelt.h"
+
+#include "idle.c"
+
+#include "rt.c"
+
+#ifdef CONFIG_SMP
+# include "cpudeadline.c"
+# include "pelt.c"
+#endif
+
+#include "cputime.c"
+#include "deadline.c"
+
diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
index 0e196f0de492..02d970a879ed 100644
--- a/kernel/sched/cpudeadline.c
+++ b/kernel/sched/cpudeadline.c
@@ -6,7 +6,6 @@
  *
  *  Author: Juri Lelli <j.lelli@sssup.it>
  */
-#include "sched.h"
 
 static inline int parent(int i)
 {
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index b7ec42732b28..78a233d43757 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -2,7 +2,6 @@
 /*
  * Simple CPU accounting cgroup controller
  */
-#include "sched.h"
 
 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
 
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index d2c072b0ef01..fca2d7de4d3d 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -15,8 +15,6 @@
  *                    Michael Trimarchi <michael@amarulasolutions.com>,
  *                    Fabio Checconi <fchecconi@gmail.com>
  */
-#include "sched.h"
-#include "pelt.h"
 
 struct dl_bandwidth def_dl_bandwidth;
 
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index d17b0a5ce6ac..8f8b5020e76a 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -6,9 +6,6 @@
  * (NOTE: these are not related to SCHED_IDLE batch scheduled
  *        tasks which are handled in sched/fair.c )
  */
-#include "sched.h"
-
-#include <trace/events/power.h>
 
 /* Linker adds these: start and end of __cpuidle functions */
 extern char __cpuidle_text_start[], __cpuidle_text_end[];
diff --git a/kernel/sched/pelt.c b/kernel/sched/pelt.c
index a554e3bbab2b..0f310768260c 100644
--- a/kernel/sched/pelt.c
+++ b/kernel/sched/pelt.c
@@ -24,10 +24,6 @@
  *  Author: Vincent Guittot <vincent.guittot@linaro.org>
  */
 
-#include <linux/sched.h>
-#include "sched.h"
-#include "pelt.h"
-
 /*
  * Approximate:
  *   val * y^n,    where y^32 ~= 0.5 (~1 scheduling period)
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 7b4f4fbbb404..ff4c044aed12 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -3,9 +3,6 @@
  * Real-Time Scheduling Class (mapped to the SCHED_FIFO and SCHED_RR
  * policies)
  */
-#include "sched.h"
-
-#include "pelt.h"
 
 int sched_rr_timeslice = RR_TIMESLICE;
 int sysctl_sched_rr_timeslice = (MSEC_PER_SEC / HZ) * RR_TIMESLICE;
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 79c7a8a2be65..f7d10b98e911 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -13,6 +13,7 @@
 #include <linux/prctl.h>
 #include <linux/ptrace_api.h>
 #include <linux/gfp_api.h>
+#include <linux/posix-timers.h>
 #include <linux/sched/clock.h>
 #include <linux/workqueue_api.h>
 #include <linux/tick.h>
@@ -113,8 +114,11 @@
 #include <linux/cpumask_api.h>
 #include <linux/ctype.h>
 #include <linux/file.h>
+#include <linux/hrtimer_api.h>
+#include <linux/interrupt.h>
 #include <linux/jiffies.h>
 #include <linux/kref_api.h>
+#include <linux/ktime_api.h>
 #include <linux/lockdep_api.h>
 #include <linux/module.h>
 #include <linux/mutex_api.h>
@@ -126,12 +130,16 @@
 #include <linux/sched/loadavg.h>
 #include <linux/sched/mm.h>
 #include <linux/sched/rseq_api.h>
+#include <linux/sched/signal.h>
 #include <linux/seq_file.h>
 #include <linux/seqlock.h>
+#include <linux/softirq.h>
+#include <linux/spinlock_api.h>
 #include <linux/syscalls_api.h>
 #include <linux/syscalls.h>
 #include <linux/topology.h>
 #include <linux/types.h>
+#include <linux/u64_stats_sync_api.h>
 #include <linux/uaccess.h>
 #include <linux/wait_api.h>
 #include <linux/workqueue_api.h>
-- 
2.32.0

[PATCH 10/15] sched/headers: Standardize kernel/sched/sched.h header dependencies

[Ingo Molnar]

kernel/sched/sched.h is a weird mix of ad-hoc headers included
in the middle of the header.

Two of them rely on being included in the middle of kernel/sched/sched.h,
due to definitions they require:

 - "stat.h" needs the rq definitions.
 - "autogroup.h" needs the task_group definition.

Move the inclusion of these two files out of kernel/sched/sched.h, and
include them in all files that require them.

Move of the rest of the header dependencies to the top of the
kernel/sched/sched.h file.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
---
 kernel/sched/build_policy.c  |  3 +++
 kernel/sched/build_utility.c |  2 ++
 kernel/sched/core.c          |  2 ++
 kernel/sched/fair.c          |  2 ++
 kernel/sched/sched.h         | 20 +++++++++++---------
 kernel/sched/stats.h         |  4 ++--
 6 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/kernel/sched/build_policy.c b/kernel/sched/build_policy.c
index 6bb384ddcfab..9a169b2f97e6 100644
--- a/kernel/sched/build_policy.c
+++ b/kernel/sched/build_policy.c
@@ -13,6 +13,9 @@
  */
 
 #include "sched.h"
+
+#include "autogroup.h"
+#include "stats.h"
 #include "pelt.h"
 
 #include "idle.c"
diff --git a/kernel/sched/build_utility.c b/kernel/sched/build_utility.c
index 31216ce0b4b3..8b2b199983bf 100644
--- a/kernel/sched/build_utility.c
+++ b/kernel/sched/build_utility.c
@@ -12,6 +12,8 @@
 
 #include "sched.h"
 #include "sched-pelt.h"
+#include "stats.h"
+#include "autogroup.h"
 
 #include <linux/sched_clock.h>
 
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index ef946123e9af..22de53710ee9 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -11,6 +11,8 @@
 #undef CREATE_TRACE_POINTS
 
 #include "sched.h"
+#include "stats.h"
+#include "autogroup.h"
 
 #include <linux/nospec.h>
 #include <linux/blkdev.h>
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 16874e112fe6..7391c9287503 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -21,6 +21,8 @@
  *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
  */
 #include "sched.h"
+#include "stats.h"
+#include "autogroup.h"
 
 /*
  * Targeted preemption latency for CPU-bound tasks:
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index f7d10b98e911..f255ec2afeca 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -96,11 +96,20 @@
 # include <asm/paravirt.h>
 #endif
 
+#include <trace/events/sched.h>
+
+#ifdef CONFIG_CGROUP_SCHED
+#include <linux/cgroup.h>
+#include <linux/psi.h>
+#endif
+
+#ifdef CONFIG_SCHED_DEBUG
+# include <linux/static_key.h>
+#endif
+
 #include "cpupri.h"
 #include "cpudeadline.h"
 
-#include <trace/events/sched.h>
-
 #ifdef CONFIG_SCHED_DEBUG
 # define SCHED_WARN_ON(x)	WARN_ONCE(x, #x)
 #else
@@ -417,9 +426,6 @@ extern bool dl_cpu_busy(unsigned int cpu);
 
 #ifdef CONFIG_CGROUP_SCHED
 
-#include <linux/cgroup.h>
-#include <linux/psi.h>
-
 struct cfs_rq;
 struct rt_rq;
 
@@ -1919,9 +1925,6 @@ extern void flush_smp_call_function_from_idle(void);
 static inline void flush_smp_call_function_from_idle(void) { }
 #endif
 
-#include "stats.h"
-#include "autogroup.h"
-
 #if defined(CONFIG_SCHED_CORE) && defined(CONFIG_SCHEDSTATS)
 
 extern void __sched_core_account_forceidle(struct rq *rq);
@@ -2016,7 +2019,6 @@ static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
  * Tunables that become constants when CONFIG_SCHED_DEBUG is off:
  */
 #ifdef CONFIG_SCHED_DEBUG
-# include <linux/static_key.h>
 # define const_debug __read_mostly
 #else
 # define const_debug const
diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h
index edc0d13fc61b..a0df79e6038c 100644
--- a/kernel/sched/stats.h
+++ b/kernel/sched/stats.h
@@ -2,10 +2,10 @@
 #ifndef _KERNEL_STATS_H
 #define _KERNEL_STATS_H
 
-#ifdef CONFIG_SCHEDSTATS
-
 #include "sched.h"
 
+#ifdef CONFIG_SCHEDSTATS
+
 extern struct static_key_false sched_schedstats;
 
 /*
-- 
2.32.0

[PATCH 11/15] sched/headers: Reorganize, clean up and optimize kernel/sched/core.c dependencies

[Ingo Molnar]

Use all generic headers from kernel/sched/sched.h that are required
for it to build.

Sort the sections alphabetically.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
---
 kernel/sched/core.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 70 insertions(+), 11 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 22de53710ee9..5eaa4211d93c 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6,7 +6,73 @@
  *
  *  Copyright (C) 1991-2002  Linus Torvalds
  */
+#include <linux/highmem.h>
+#include <linux/hrtimer_api.h>
+#include <linux/ktime_api.h>
+#include <linux/sched/signal.h>
+#include <linux/syscalls_api.h>
+#include <linux/debug_locks.h>
+#include <linux/prefetch.h>
+#include <linux/capability.h>
+#include <linux/pgtable_api.h>
+#include <linux/wait_bit.h>
+#include <linux/jiffies.h>
+#include <linux/spinlock_api.h>
+#include <linux/cpumask_api.h>
+#include <linux/lockdep_api.h>
+#include <linux/hardirq.h>
+#include <linux/softirq.h>
+#include <linux/refcount_api.h>
+#include <linux/topology.h>
+#include <linux/sched/clock.h>
+#include <linux/sched/cond_resched.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/isolation.h>
+#include <linux/sched/loadavg.h>
+#include <linux/sched/mm.h>
+#include <linux/sched/nohz.h>
+#include <linux/sched/rseq_api.h>
+#include <linux/sched/rt.h>
+
+#include <linux/blkdev.h>
+#include <linux/context_tracking.h>
+#include <linux/cpuset.h>
+#include <linux/delayacct.h>
+#include <linux/init_task.h>
+#include <linux/interrupt.h>
+#include <linux/ioprio.h>
+#include <linux/kallsyms.h>
+#include <linux/kcov.h>
+#include <linux/kprobes.h>
+#include <linux/llist_api.h>
+#include <linux/mmu_context.h>
+#include <linux/mmzone.h>
+#include <linux/mutex_api.h>
+#include <linux/nmi.h>
+#include <linux/nospec.h>
+#include <linux/perf_event_api.h>
+#include <linux/profile.h>
+#include <linux/psi.h>
+#include <linux/rcuwait_api.h>
+#include <linux/sched/wake_q.h>
+#include <linux/scs.h>
+#include <linux/slab.h>
+#include <linux/syscalls.h>
+#include <linux/vtime.h>
+#include <linux/wait_api.h>
+#include <linux/workqueue_api.h>
+
+#ifdef CONFIG_PREEMPT_DYNAMIC
+# include <linux/entry-common.h>
+#endif
+
+#include <uapi/linux/sched/types.h>
+
+#include <asm/switch_to.h>
+#include <asm/tlb.h>
+
 #define CREATE_TRACE_POINTS
+#include <linux/sched/rseq_api.h>
 #include <trace/events/sched.h>
 #undef CREATE_TRACE_POINTS
 
@@ -14,22 +80,15 @@
 #include "stats.h"
 #include "autogroup.h"
 
-#include <linux/nospec.h>
-#include <linux/blkdev.h>
-#include <linux/jump_label.h>
-#include <linux/kcov.h>
-#include <linux/scs.h>
-
-#include <asm/switch_to.h>
-#include <asm/tlb.h>
+#include "autogroup.h"
+#include "pelt.h"
+#include "smp.h"
+#include "stats.h"
 
 #include "../workqueue_internal.h"
 #include "../../fs/io-wq.h"
 #include "../smpboot.h"
 
-#include "pelt.h"
-#include "smp.h"
-
 /*
  * Export tracepoints that act as a bare tracehook (ie: have no trace event
  * associated with them) to allow external modules to probe them.
-- 
2.32.0

[PATCH 12/15] sched/headers: Reorganize, clean up and optimize kernel/sched/fair.c dependencies

[Ingo Molnar]

Use all generic headers from kernel/sched/sched.h that are required
for it to build.

Sort the sections alphabetically.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
---
 kernel/sched/fair.c | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 7391c9287503..89d21fda106c 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -20,6 +20,35 @@
  *  Adaptive scheduling granularity, math enhancements by Peter Zijlstra
  *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
  */
+#include <linux/energy_model.h>
+#include <linux/mmap_lock.h>
+#include <linux/hugetlb_inline.h>
+#include <linux/jiffies.h>
+#include <linux/mm_api.h>
+#include <linux/highmem.h>
+#include <linux/spinlock_api.h>
+#include <linux/cpumask_api.h>
+#include <linux/lockdep_api.h>
+#include <linux/softirq.h>
+#include <linux/refcount_api.h>
+#include <linux/topology.h>
+#include <linux/sched/clock.h>
+#include <linux/sched/cond_resched.h>
+#include <linux/sched/cputime.h>
+#include <linux/sched/isolation.h>
+
+#include <linux/cpuidle.h>
+#include <linux/interrupt.h>
+#include <linux/mempolicy.h>
+#include <linux/mutex_api.h>
+#include <linux/profile.h>
+#include <linux/psi.h>
+#include <linux/ratelimit.h>
+
+#include <asm/switch_to.h>
+
+#include <linux/sched/cond_resched.h>
+
 #include "sched.h"
 #include "stats.h"
 #include "autogroup.h"
-- 
2.32.0

[PATCH 13/15] sched/headers: Reorganize, clean up and optimize kernel/sched/build_policy.c dependencies

[Ingo Molnar]

Use all generic headers from kernel/sched/sched.h that are required
for it to build.

Sort the sections alphabetically.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
---
 kernel/sched/build_policy.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/kernel/sched/build_policy.c b/kernel/sched/build_policy.c
index 9a169b2f97e6..a2e4023771a0 100644
--- a/kernel/sched/build_policy.c
+++ b/kernel/sched/build_policy.c
@@ -12,12 +12,36 @@
  * core.c and fair.c are built separately.
  */
 
+/* Headers: */
+#include <linux/sched/clock.h>
+#include <linux/sched/cputime.h>
+#include <linux/sched/posix-timers.h>
+#include <linux/sched/rt.h>
+
+#include <linux/cpuidle.h>
+#include <linux/jiffies.h>
+#include <linux/livepatch.h>
+#include <linux/psi.h>
+#include <linux/seqlock_api.h>
+#include <linux/slab.h>
+#include <linux/suspend.h>
+#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"
 
 #include "autogroup.h"
 #include "stats.h"
 #include "pelt.h"
 
+/* Source code modules: */
+
 #include "idle.c"
 
 #include "rt.c"
-- 
2.32.0

[PATCH 14/15] sched/headers: Reorganize, clean up and optimize kernel/sched/build_utility.c dependencies

[Ingo Molnar]

Use all generic headers from kernel/sched/sched.h that are required
for it to build.

Sort the sections alphabetically.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
---
 kernel/sched/build_utility.c | 43 +++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 41 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/build_utility.c b/kernel/sched/build_utility.c
index 8b2b199983bf..bc2f4d648209 100644
--- a/kernel/sched/build_utility.c
+++ b/kernel/sched/build_utility.c
@@ -9,14 +9,53 @@
  *   coalescing source files to amortize header inclusion
  *   cost. )
  */
+#include <linux/sched/clock.h>
+#include <linux/sched/cputime.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/isolation.h>
+#include <linux/sched/loadavg.h>
+#include <linux/sched/mm.h>
+#include <linux/sched/rseq_api.h>
+#include <linux/sched/task_stack.h>
+
+#include <linux/cpufreq.h>
+#include <linux/cpumask_api.h>
+#include <linux/cpuset.h>
+#include <linux/ctype.h>
+#include <linux/debugfs.h>
+#include <linux/energy_model.h>
+#include <linux/hashtable_api.h>
+#include <linux/irq.h>
+#include <linux/kobject_api.h>
+#include <linux/membarrier.h>
+#include <linux/mempolicy.h>
+#include <linux/nmi.h>
+#include <linux/nospec.h>
+#include <linux/proc_fs.h>
+#include <linux/psi.h>
+#include <linux/psi.h>
+#include <linux/ptrace_api.h>
+#include <linux/sched_clock.h>
+#include <linux/security.h>
+#include <linux/spinlock_api.h>
+#include <linux/swait_api.h>
+#include <linux/timex.h>
+#include <linux/utsname.h>
+#include <linux/wait_api.h>
+#include <linux/workqueue_api.h>
+
+#ifdef CONFIG_PARAVIRT
+# include <asm/paravirt.h>
+#endif
+
+#include <uapi/linux/prctl.h>
+#include <uapi/linux/sched/types.h>
 
 #include "sched.h"
 #include "sched-pelt.h"
 #include "stats.h"
 #include "autogroup.h"
 
-#include <linux/sched_clock.h>
-
 #include "clock.c"
 
 #ifdef CONFIG_CGROUP_CPUACCT
-- 
2.32.0

[PATCH 15/15] sched/headers: Reorganize, clean up and optimize kernel/sched/sched.h dependencies

[Ingo Molnar]

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 --
 kernel/sched/build_utility.c |   6 +--
 kernel/sched/sched.h         | 147 +++++++++++++++++++--------------------------------------------
 kernel/sched/stats.h         |   2 -
 4 files changed, 46 insertions(+), 113 deletions(-)

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"
diff --git a/kernel/sched/build_utility.c b/kernel/sched/build_utility.c
index bc2f4d648209..eec0849b2aae 100644
--- a/kernel/sched/build_utility.c
+++ b/kernel/sched/build_utility.c
@@ -44,13 +44,11 @@
 #include <linux/wait_api.h>
 #include <linux/workqueue_api.h>
 
-#ifdef CONFIG_PARAVIRT
-# include <asm/paravirt.h>
-#endif
-
 #include <uapi/linux/prctl.h>
 #include <uapi/linux/sched/types.h>
 
+#include <asm/switch_to.h>
+
 #include "sched.h"
 #include "sched-pelt.h"
 #include "stats.h"
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index f255ec2afeca..0d4217965561 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -5,158 +5,97 @@
 #ifndef _KERNEL_SCHED_SCHED_H
 #define _KERNEL_SCHED_SCHED_H
 
-#include <linux/sched.h>
-#include <linux/cpumask.h>
-#include <linux/ktime_api.h>
-#include <linux/cgroup_api.h>
-#include <linux/topology.h>
-#include <linux/prctl.h>
-#include <linux/ptrace_api.h>
-#include <linux/gfp_api.h>
-#include <linux/posix-timers.h>
-#include <linux/sched/clock.h>
-#include <linux/workqueue_api.h>
-#include <linux/tick.h>
-#include <linux/ktime_api.h>
-#include <linux/swait_api.h>
-#include <linux/hashtable_api.h>
-#include <linux/cpufreq.h>
-#include <linux/utsname.h>
-
-#include <asm/irq_regs.h>
-
 #include <linux/sched/affinity.h>
 #include <linux/sched/autogroup.h>
-#include <linux/sched/clock.h>
-#include <linux/sched/coredump.h>
 #include <linux/sched/cpufreq.h>
-#include <linux/sched/cputime.h>
 #include <linux/sched/deadline.h>
-#include <linux/sched/debug.h>
-#include <linux/sched/hotplug.h>
-#include <linux/sched/idle.h>
-#include <linux/sched/init.h>
-#include <linux/sched/isolation.h>
-#include <linux/sched/jobctl.h>
+#include <linux/sched.h>
 #include <linux/sched/loadavg.h>
 #include <linux/sched/mm.h>
-#include <linux/sched/nohz.h>
-#include <linux/sched/numa_balancing.h>
-#include <linux/sched/prio.h>
 #include <linux/sched/rseq_api.h>
-#include <linux/sched/rt.h>
 #include <linux/sched/signal.h>
 #include <linux/sched/smt.h>
 #include <linux/sched/stat.h>
 #include <linux/sched/sysctl.h>
+#include <linux/sched/task_flags.h>
 #include <linux/sched/task.h>
-#include <linux/sched/task_stack.h>
-#include <linux/sched/thread_info_api.h>
 #include <linux/sched/topology.h>
-#include <linux/sched/user.h>
-#include <linux/sched/wake_q.h>
-#include <linux/sched/xacct.h>
-
-#include <uapi/linux/sched/types.h>
-
-#include <linux/binfmts.h>
-#include <linux/bitops.h>
-#include <linux/compat.h>
-#include <linux/context_tracking.h>
-#include <linux/cpufreq.h>
-#include <linux/cpuidle.h>
-#include <linux/cpuset.h>
-#include <linux/ctype.h>
-#include <linux/debugfs.h>
-#include <linux/delayacct.h>
-#include <linux/energy_model.h>
-#include <linux/init_task.h>
-#include <linux/kprobes.h>
-#include <linux/kthread.h>
-#include <linux/membarrier.h>
-#include <linux/migrate.h>
-#include <linux/mmu_context.h>
-#include <linux/nmi.h>
-#include <linux/proc_fs.h>
-#include <linux/prefetch.h>
-#include <linux/profile.h>
-#include <linux/psi.h>
-#include <linux/ratelimit.h>
-#include <linux/rcupdate_wait.h>
-#include <linux/security.h>
-#include <linux/stop_machine.h>
-#include <linux/suspend.h>
-#include <linux/swait.h>
-#include <linux/syscalls.h>
-#include <linux/task_work.h>
-#include <linux/tsacct_kern.h>
-#include <linux/hrtimer_api.h>
-
-#ifdef CONFIG_PARAVIRT
-# include <asm/paravirt.h>
-#endif
-
-#include <trace/events/sched.h>
-
-#ifdef CONFIG_CGROUP_SCHED
-#include <linux/cgroup.h>
-#include <linux/psi.h>
-#endif
-
-#ifdef CONFIG_SCHED_DEBUG
-# include <linux/static_key.h>
-#endif
-
-#include "cpupri.h"
-#include "cpudeadline.h"
-
-#ifdef CONFIG_SCHED_DEBUG
-# define SCHED_WARN_ON(x)	WARN_ONCE(x, #x)
-#else
-# define SCHED_WARN_ON(x)	({ (void)(x), 0; })
-#endif
 
+#include <linux/atomic.h>
 #include <linux/bitmap.h>
+#include <linux/bug.h>
 #include <linux/capability.h>
+#include <linux/cgroup_api.h>
 #include <linux/cgroup.h>
 #include <linux/cpufreq.h>
 #include <linux/cpumask_api.h>
 #include <linux/ctype.h>
 #include <linux/file.h>
+#include <linux/fs_api.h>
 #include <linux/hrtimer_api.h>
 #include <linux/interrupt.h>
+#include <linux/irq_work.h>
 #include <linux/jiffies.h>
 #include <linux/kref_api.h>
+#include <linux/kthread.h>
 #include <linux/ktime_api.h>
 #include <linux/lockdep_api.h>
+#include <linux/lockdep.h>
+#include <linux/minmax.h>
+#include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/mutex_api.h>
+#include <linux/plist.h>
 #include <linux/poll.h>
 #include <linux/proc_fs.h>
+#include <linux/profile.h>
 #include <linux/psi.h>
-#include <linux/sched/affinity.h>
-#include <linux/sched.h>
-#include <linux/sched/loadavg.h>
-#include <linux/sched/mm.h>
-#include <linux/sched/rseq_api.h>
-#include <linux/sched/signal.h>
+#include <linux/rcupdate.h>
 #include <linux/seq_file.h>
 #include <linux/seqlock.h>
 #include <linux/softirq.h>
 #include <linux/spinlock_api.h>
+#include <linux/static_key.h>
+#include <linux/stop_machine.h>
 #include <linux/syscalls_api.h>
 #include <linux/syscalls.h>
+#include <linux/tick.h>
 #include <linux/topology.h>
 #include <linux/types.h>
 #include <linux/u64_stats_sync_api.h>
 #include <linux/uaccess.h>
 #include <linux/wait_api.h>
+#include <linux/wait_bit.h>
 #include <linux/workqueue_api.h>
 
 #include <trace/events/power.h>
+#include <trace/events/sched.h>
 
 #include "../workqueue_internal.h"
 
+#ifdef CONFIG_CGROUP_SCHED
+#include <linux/cgroup.h>
+#include <linux/psi.h>
+#endif
+
+#ifdef CONFIG_SCHED_DEBUG
+# include <linux/static_key.h>
+#endif
+
+#ifdef CONFIG_PARAVIRT
+# include <asm/paravirt.h>
+# include <asm/paravirt_api_clock.h>
+#endif
+
+#include "cpupri.h"
+#include "cpudeadline.h"
+
+#ifdef CONFIG_SCHED_DEBUG
+# define SCHED_WARN_ON(x)      WARN_ONCE(x, #x)
+#else
+# define SCHED_WARN_ON(x)      ({ (void)(x), 0; })
+#endif
+
 struct rq;
 struct cpuidle_state;
 
@@ -1925,6 +1864,8 @@ extern void flush_smp_call_function_from_idle(void);
 static inline void flush_smp_call_function_from_idle(void) { }
 #endif
 
+#include "stats.h"
+
 #if defined(CONFIG_SCHED_CORE) && defined(CONFIG_SCHEDSTATS)
 
 extern void __sched_core_account_forceidle(struct rq *rq);
diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h
index a0df79e6038c..baa839c1ba96 100644
--- a/kernel/sched/stats.h
+++ b/kernel/sched/stats.h
@@ -2,8 +2,6 @@
 #ifndef _KERNEL_STATS_H
 #define _KERNEL_STATS_H
 
-#include "sched.h"
-
 #ifdef CONFIG_SCHEDSTATS
 
 extern struct static_key_false sched_schedstats;
-- 
2.32.0

Re: [PATCH 09/15] sched/headers: Introduce kernel/sched/build_policy.c and build multiple .c files there

[suhui_kernel]

Hi Ingo, Since commit f96eca432015ddc1b621632488ebc345bca06791 merged, the
scripts/clang-tools/gen_compile_commands.py can't work very well.
  In this patch the build_policy.c and build_utility.c include kernel/sched/xxx.c(
such as rt.c idle.c...), so it compile the build_utility.o build_policy.o directly,
and it won't generate kernel/sched/xxx.c(such as rt.o idle.o), so the gen_compile_commands.py
can't work.
  It will report "[8/23/2022, 3:24:06 PM] "rt.c" not found in "${workspaceFolder}/compile_commands.json".
'includePath' from c_cpp_properties.json in folder 'linux' will be used for this file instead.".
  And i test the kdump & crash tools, it can find the functions by line in kernel/sched/xxx.c(
such as rt.c idle.c), it works well.
  I can't solve this report error, so i want to get help.
  Maybe we change the gen_compile_commands.py code can solve this problem or
can we revert this change?(3.9% build wall time decrease really matter? it will
destory all tool's parse result which depends on the compiled file result).

Re: [PATCH 09/15] sched/headers: Introduce kernel/sched/build_policy.c and build multiple .c files there

[Thomas Gleixner]

On Tue, Aug 23 2022 at 15:47, suhui kernel wrote:
> Hi Ingo, Since commit f96eca432015ddc1b621632488ebc345bca06791 merged, the
> scripts/clang-tools/gen_compile_commands.py can't work very well.
>
>   In this patch the build_policy.c and build_utility.c include kernel/sched/xxx.c(
> such as rt.c idle.c...), so it compile the build_utility.o build_policy.o directly,
> and it won't generate kernel/sched/xxx.c(such as rt.o idle.o), so the gen_compile_commands.py
> can't work.

gen_compile_commands.py works perfectly fine and generates the entries
for build_policy.o and built_utility.o as expected.

gen_compile_commands.py scans the build tree for .cmd files and extracts
the command line from those files into the the json file. As there is no
.cmd file for the .c files which are included into build_*.c there wont
be entries in the json file either.

>   It will report "[8/23/2022, 3:24:06 PM] "rt.c" not found in "${workspaceFolder}/compile_commands.json".
> 'includePath' from c_cpp_properties.json in folder 'linux' will be
> used for this file instead.".

No idea where this message comes from, but certainly not from
gen_compile_commands.py because that generates the file.

The clang-tidy kernel build target generates and uses that file and that
works perfectly fine.

So what exactly broke?

Thanks,

        tglx