Re: [PATCH v2 6/6] cpu/idle.c: move to sched/idle.c

Nicolas Pitre
2014-01-30T16:03:36Z

On Thu, 30 Jan 2014, Peter Zijlstra wrote:

> On Wed, Jan 29, 2014 at 12:45:13PM -0500, Nicolas Pitre wrote:
> > Integration of cpuidle with the scheduler requires that the idle loop be
> > closely integrated with the scheduler proper. Moving cpu/idle.c into the
> > sched directory will allow for a smoother integration, and eliminate a
> > subdirectory which contained only one source file.
> >
> > Signed-off-by: Nicolas Pitre <nico@linaro.org>
> > ---
> > kernel/Makefile | 1 -
> > kernel/cpu/Makefile | 1 -
> > kernel/sched/Makefile | 2 +-
> > kernel/{cpu => sched}/idle.c | 0
> > 4 files changed, 1 insertion(+), 3 deletions(-)
> > delete mode 100644 kernel/cpu/Makefile
> > rename kernel/{cpu => sched}/idle.c (100%)
>
> > --- a/kernel/sched/Makefile
> > +++ b/kernel/sched/Makefile
> > @@ -11,7 +11,7 @@ ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y)
> > CFLAGS_core.o := $(PROFILING) -fno-omit-frame-pointer
> > endif
> >
> > -obj-y += core.o proc.o clock.o cputime.o idle_task.o fair.o rt.o stop_task.o
> > +obj-y += core.o proc.o clock.o cputime.o idle_task.o idle.o fair.o rt.o stop_task.o
> > obj-y += wait.o completion.o
> > obj-$(CONFIG_SMP) += cpupri.o
> > obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o
> > diff --git a/kernel/cpu/idle.c b/kernel/sched/idle.c
> > similarity index 100%
> > rename from kernel/cpu/idle.c
> > rename to kernel/sched/idle.c
>
> This is not a valid patch for PATCH(1). Please try again.

Don't you use git? ;-)

Here's a plain patch:

----- >8

>From 1bf40eb80a44633094e94986a74bd5ffa222f9d4 Mon Sep 17 00:00:00 2001
From: Nicolas Pitre <nicolas.pitre@linaro.org>
Date: Sun, 26 Jan 2014 23:42:01 -0500
Subject: [PATCH] cpu/idle.c: move to sched/idle.c

Integration of cpuidle with the scheduler requires that the idle loop be
closely integrated with the scheduler proper. Moving cpu/idle.c into the
sched directory will allow for a smoother integration, and eliminate a
subdirectory which contained only one source file.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
kernel/Makefile | 1 -
kernel/cpu/Makefile | 1 -
kernel/cpu/idle.c | 144 --------------------------------------------------
kernel/sched/Makefile | 2 +-
kernel/sched/idle.c | 144 ++++++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 145 insertions(+), 147 deletions(-)
delete mode 100644 kernel/cpu/Makefile
delete mode 100644 kernel/cpu/idle.c
create mode 100644 kernel/sched/idle.c

diff --git a/kernel/Makefile b/kernel/Makefile
index bc010ee272..6f1c7e5cfc 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -22,7 +22,6 @@ obj-y += sched/
obj-y += locking/
obj-y += power/
obj-y += printk/
-obj-y += cpu/
obj-y += irq/
obj-y += rcu/

diff --git a/kernel/cpu/Makefile b/kernel/cpu/Makefile
deleted file mode 100644
index 59ab052ef7..0000000000
--- a/kernel/cpu/Makefile
+++ /dev/null
@@ -1 +0,0 @@
-obj-y = idle.o
diff --git a/kernel/cpu/idle.c b/kernel/cpu/idle.c
deleted file mode 100644
index 14ca43430a..0000000000
--- a/kernel/cpu/idle.c
+++ /dev/null
@@ -1,144 +0,0 @@
-/*
- * Generic entry point for the idle threads
- */
-#include <linux/sched.h>
-#include <linux/cpu.h>
-#include <linux/cpuidle.h>
-#include <linux/tick.h>
-#include <linux/mm.h>
-#include <linux/stackprotector.h>
-
-#include <asm/tlb.h>
-
-#include <trace/events/power.h>
-
-static int __read_mostly cpu_idle_force_poll;
-
-void cpu_idle_poll_ctrl(bool enable)
-{
- if (enable) {
- cpu_idle_force_poll++;
- } else {
- cpu_idle_force_poll--;
- WARN_ON_ONCE(cpu_idle_force_poll < 0);
- }
-}
-
-#ifdef CONFIG_GENERIC_IDLE_POLL_SETUP
-static int __init cpu_idle_poll_setup(char *__unused)
-{
- cpu_idle_force_poll = 1;
- return 1;
-}
-__setup("nohlt", cpu_idle_poll_setup);
-
-static int __init cpu_idle_nopoll_setup(char *__unused)
-{
- cpu_idle_force_poll = 0;
- return 1;
-}
-__setup("hlt", cpu_idle_nopoll_setup);
-#endif
-
-static inline int cpu_idle_poll(void)
-{
- rcu_idle_enter();
- trace_cpu_idle_rcuidle(0, smp_processor_id());
- local_irq_enable();
- while (!tif_need_resched())
- cpu_relax();
- trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
- rcu_idle_exit();
- return 1;
-}
-
-/* Weak implementations for optional arch specific functions */
-void __weak arch_cpu_idle_prepare(void) { }
-void __weak arch_cpu_idle_enter(void) { }
-void __weak arch_cpu_idle_exit(void) { }
-void __weak arch_cpu_idle_dead(void) { }
-void __weak arch_cpu_idle(void)
-{
- cpu_idle_force_poll = 1;
- local_irq_enable();
-}
-
-/*
- * Generic idle loop implementation
- */
-static void cpu_idle_loop(void)
-{
- while (1) {
- tick_nohz_idle_enter();
-
- while (!need_resched()) {
- check_pgt_cache();
- rmb();
-
- if (cpu_is_offline(smp_processor_id()))
- arch_cpu_idle_dead();
-
- local_irq_disable();
- arch_cpu_idle_enter();
-
- /*
- * In poll mode we reenable interrupts and spin.
- *
- * Also if we detected in the wakeup from idle
- * path that the tick broadcast device expired
- * for us, we don't want to go deep idle as we
- * know that the IPI is going to arrive right
- * away
- */
- if (cpu_idle_force_poll || tick_check_broadcast_expired()) {
- cpu_idle_poll();
- } else {
- if (!current_clr_polling_and_test()) {
- stop_critical_timings();
- rcu_idle_enter();
- if (cpuidle_idle_call())
- arch_cpu_idle();
- if (WARN_ON_ONCE(irqs_disabled()))
- local_irq_enable();
- rcu_idle_exit();
- start_critical_timings();
- } else {
- local_irq_enable();
- }
- __current_set_polling();
- }
- arch_cpu_idle_exit();
- /*
- * We need to test and propagate the TIF_NEED_RESCHED
- * bit here because we might not have send the
- * reschedule IPI to idle tasks.
- */
- if (tif_need_resched())
- set_preempt_need_resched();
- }
- tick_nohz_idle_exit();
- schedule_preempt_disabled();
- }
-}
-
-void cpu_startup_entry(enum cpuhp_state state)
-{
- /*
- * This #ifdef needs to die, but it's too late in the cycle to
- * make this generic (arm and sh have never invoked the canary
- * init for the non boot cpus!). Will be fixed in 3.11
- */
-#ifdef CONFIG_X86
- /*
- * If we're the non-boot CPU, nothing set the stack canary up
- * for us. The boot CPU already has it initialized but no harm
- * in doing it again. This is a good place for updating it, as
- * we wont ever return from this function (so the invalid
- * canaries already on the stack wont ever trigger).
- */
- boot_init_stack_canary();
-#endif
- __current_set_polling();
- arch_cpu_idle_prepare();
- cpu_idle_loop();
-}
diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
index 7b621409cf..ac3e0ea68f 100644
--- a/kernel/sched/Makefile
+++ b/kernel/sched/Makefile
@@ -11,7 +11,7 @@ ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y)
CFLAGS_core.o := $(PROFILING) -fno-omit-frame-pointer
endif

-obj-y += core.o proc.o clock.o cputime.o idle_task.o fair.o rt.o stop_task.o
+obj-y += core.o proc.o clock.o cputime.o idle_task.o idle.o fair.o rt.o stop_task.o
obj-y += wait.o completion.o
obj-$(CONFIG_SMP) += cpupri.o
obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
new file mode 100644
index 0000000000..14ca43430a
--- /dev/null
+++ b/kernel/sched/idle.c
@@ -0,0 +1,144 @@
+/*
+ * Generic entry point for the idle threads
+ */
+#include <linux/sched.h>
+#include <linux/cpu.h>
+#include <linux/cpuidle.h>
+#include <linux/tick.h>
+#include <linux/mm.h>
+#include <linux/stackprotector.h>
+
+#include <asm/tlb.h>
+
+#include <trace/events/power.h>
+
+static int __read_mostly cpu_idle_force_poll;
+
+void cpu_idle_poll_ctrl(bool enable)
+{
+ if (enable) {
+ cpu_idle_force_poll++;
+ } else {
+ cpu_idle_force_poll--;
+ WARN_ON_ONCE(cpu_idle_force_poll < 0);
+ }
+}
+
+#ifdef CONFIG_GENERIC_IDLE_POLL_SETUP
+static int __init cpu_idle_poll_setup(char *__unused)
+{
+ cpu_idle_force_poll = 1;
+ return 1;
+}
+__setup("nohlt", cpu_idle_poll_setup);
+
+static int __init cpu_idle_nopoll_setup(char *__unused)
+{
+ cpu_idle_force_poll = 0;
+ return 1;
+}
+__setup("hlt", cpu_idle_nopoll_setup);
+#endif
+
+static inline int cpu_idle_poll(void)
+{
+ rcu_idle_enter();
+ trace_cpu_idle_rcuidle(0, smp_processor_id());
+ local_irq_enable();
+ while (!tif_need_resched())
+ cpu_relax();
+ trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
+ rcu_idle_exit();
+ return 1;
+}
+
+/* Weak implementations for optional arch specific functions */
+void __weak arch_cpu_idle_prepare(void) { }
+void __weak arch_cpu_idle_enter(void) { }
+void __weak arch_cpu_idle_exit(void) { }
+void __weak arch_cpu_idle_dead(void) { }
+void __weak arch_cpu_idle(void)
+{
+ cpu_idle_force_poll = 1;
+ local_irq_enable();
+}
+
+/*
+ * Generic idle loop implementation
+ */
+static void cpu_idle_loop(void)
+{
+ while (1) {
+ tick_nohz_idle_enter();
+
+ while (!need_resched()) {
+ check_pgt_cache();
+ rmb();
+
+ if (cpu_is_offline(smp_processor_id()))
+ arch_cpu_idle_dead();
+
+ local_irq_disable();
+ arch_cpu_idle_enter();
+
+ /*
+ * In poll mode we reenable interrupts and spin.
+ *
+ * Also if we detected in the wakeup from idle
+ * path that the tick broadcast device expired
+ * for us, we don't want to go deep idle as we
+ * know that the IPI is going to arrive right
+ * away
+ */
+ if (cpu_idle_force_poll || tick_check_broadcast_expired()) {
+ cpu_idle_poll();
+ } else {
+ if (!current_clr_polling_and_test()) {
+ stop_critical_timings();
+ rcu_idle_enter();
+ if (cpuidle_idle_call())
+ arch_cpu_idle();
+ if (WARN_ON_ONCE(irqs_disabled()))
+ local_irq_enable();
+ rcu_idle_exit();
+ start_critical_timings();
+ } else {
+ local_irq_enable();
+ }
+ __current_set_polling();
+ }
+ arch_cpu_idle_exit();
+ /*
+ * We need to test and propagate the TIF_NEED_RESCHED
+ * bit here because we might not have send the
+ * reschedule IPI to idle tasks.
+ */
+ if (tif_need_resched())
+ set_preempt_need_resched();
+ }
+ tick_nohz_idle_exit();
+ schedule_preempt_disabled();
+ }
+}
+
+void cpu_startup_entry(enum cpuhp_state state)
+{
+ /*
+ * This #ifdef needs to die, but it's too late in the cycle to
+ * make this generic (arm and sh have never invoked the canary
+ * init for the non boot cpus!). Will be fixed in 3.11
+ */
+#ifdef CONFIG_X86
+ /*
+ * If we're the non-boot CPU, nothing set the stack canary up
+ * for us. The boot CPU already has it initialized but no harm
+ * in doing it again. This is a good place for updating it, as
+ * we wont ever return from this function (so the invalid
+ * canaries already on the stack wont ever trigger).
+ */
+ boot_init_stack_canary();
+#endif
+ __current_set_polling();
+ arch_cpu_idle_prepare();
+ cpu_idle_loop();
+}
--
1.8.4.108.g55ea5f6