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

Ingo Molnar
2022-03-15T08:45:14Z

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