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-rw-r--r--arch/x86/kernel/process.c6
-rw-r--r--drivers/acpi/processor_idle.c46
-rw-r--r--drivers/idle/intel_idle.c2
-rw-r--r--include/linux/sched.h78
-rw-r--r--include/linux/thread_info.h2
-rw-r--r--kernel/cpu/idle.c9
6 files changed, 91 insertions, 52 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index c83516be1052..3fb8d95ab8b5 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -391,9 +391,9 @@ static void amd_e400_idle(void)
* The switch back from broadcast mode needs to be
* called with interrupts disabled.
*/
- local_irq_disable();
- clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
- local_irq_enable();
+ local_irq_disable();
+ clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
+ local_irq_enable();
} else
default_idle();
}
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index f98dd00b51a9..c7414a545a4f 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -119,17 +119,10 @@ static struct dmi_system_id processor_power_dmi_table[] = {
*/
static void acpi_safe_halt(void)
{
- current_thread_info()->status &= ~TS_POLLING;
- /*
- * TS_POLLING-cleared state must be visible before we
- * test NEED_RESCHED:
- */
- smp_mb();
- if (!need_resched()) {
+ if (!tif_need_resched()) {
safe_halt();
local_irq_disable();
}
- current_thread_info()->status |= TS_POLLING;
}
#ifdef ARCH_APICTIMER_STOPS_ON_C3
@@ -737,6 +730,11 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev,
if (unlikely(!pr))
return -EINVAL;
+ if (cx->entry_method == ACPI_CSTATE_FFH) {
+ if (current_set_polling_and_test())
+ return -EINVAL;
+ }
+
lapic_timer_state_broadcast(pr, cx, 1);
acpi_idle_do_entry(cx);
@@ -790,18 +788,9 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
if (unlikely(!pr))
return -EINVAL;
- if (cx->entry_method != ACPI_CSTATE_FFH) {
- current_thread_info()->status &= ~TS_POLLING;
- /*
- * TS_POLLING-cleared state must be visible before we test
- * NEED_RESCHED:
- */
- smp_mb();
-
- if (unlikely(need_resched())) {
- current_thread_info()->status |= TS_POLLING;
+ if (cx->entry_method == ACPI_CSTATE_FFH) {
+ if (current_set_polling_and_test())
return -EINVAL;
- }
}
/*
@@ -819,9 +808,6 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
sched_clock_idle_wakeup_event(0);
- if (cx->entry_method != ACPI_CSTATE_FFH)
- current_thread_info()->status |= TS_POLLING;
-
lapic_timer_state_broadcast(pr, cx, 0);
return index;
}
@@ -858,18 +844,9 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
}
}
- if (cx->entry_method != ACPI_CSTATE_FFH) {
- current_thread_info()->status &= ~TS_POLLING;
- /*
- * TS_POLLING-cleared state must be visible before we test
- * NEED_RESCHED:
- */
- smp_mb();
-
- if (unlikely(need_resched())) {
- current_thread_info()->status |= TS_POLLING;
+ if (cx->entry_method == ACPI_CSTATE_FFH) {
+ if (current_set_polling_and_test())
return -EINVAL;
- }
}
acpi_unlazy_tlb(smp_processor_id());
@@ -915,9 +892,6 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
sched_clock_idle_wakeup_event(0);
- if (cx->entry_method != ACPI_CSTATE_FFH)
- current_thread_info()->status |= TS_POLLING;
-
lapic_timer_state_broadcast(pr, cx, 0);
return index;
}
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index fa6964d8681a..f116d664b473 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -359,7 +359,7 @@ static int intel_idle(struct cpuidle_device *dev,
if (!(lapic_timer_reliable_states & (1 << (cstate))))
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu);
- if (!need_resched()) {
+ if (!current_set_polling_and_test()) {
__monitor((void *)&current_thread_info()->flags, 0, 0);
smp_mb();
diff --git a/include/linux/sched.h b/include/linux/sched.h
index b5344de1658b..e783ec52295a 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2479,34 +2479,98 @@ static inline int tsk_is_polling(struct task_struct *p)
{
return task_thread_info(p)->status & TS_POLLING;
}
-static inline void current_set_polling(void)
+static inline void __current_set_polling(void)
{
current_thread_info()->status |= TS_POLLING;
}
-static inline void current_clr_polling(void)
+static inline bool __must_check current_set_polling_and_test(void)
+{
+ __current_set_polling();
+
+ /*
+ * Polling state must be visible before we test NEED_RESCHED,
+ * paired by resched_task()
+ */
+ smp_mb();
+
+ return unlikely(tif_need_resched());
+}
+
+static inline void __current_clr_polling(void)
{
current_thread_info()->status &= ~TS_POLLING;
- smp_mb__after_clear_bit();
+}
+
+static inline bool __must_check current_clr_polling_and_test(void)
+{
+ __current_clr_polling();
+
+ /*
+ * Polling state must be visible before we test NEED_RESCHED,
+ * paired by resched_task()
+ */
+ smp_mb();
+
+ return unlikely(tif_need_resched());
}
#elif defined(TIF_POLLING_NRFLAG)
static inline int tsk_is_polling(struct task_struct *p)
{
return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
}
-static inline void current_set_polling(void)
+
+static inline void __current_set_polling(void)
{
set_thread_flag(TIF_POLLING_NRFLAG);
}
-static inline void current_clr_polling(void)
+static inline bool __must_check current_set_polling_and_test(void)
+{
+ __current_set_polling();
+
+ /*
+ * Polling state must be visible before we test NEED_RESCHED,
+ * paired by resched_task()
+ *
+ * XXX: assumes set/clear bit are identical barrier wise.
+ */
+ smp_mb__after_clear_bit();
+
+ return unlikely(tif_need_resched());
+}
+
+static inline void __current_clr_polling(void)
{
clear_thread_flag(TIF_POLLING_NRFLAG);
}
+
+static inline bool __must_check current_clr_polling_and_test(void)
+{
+ __current_clr_polling();
+
+ /*
+ * Polling state must be visible before we test NEED_RESCHED,
+ * paired by resched_task()
+ */
+ smp_mb__after_clear_bit();
+
+ return unlikely(tif_need_resched());
+}
+
#else
static inline int tsk_is_polling(struct task_struct *p) { return 0; }
-static inline void current_set_polling(void) { }
-static inline void current_clr_polling(void) { }
+static inline void __current_set_polling(void) { }
+static inline void __current_clr_polling(void) { }
+
+static inline bool __must_check current_set_polling_and_test(void)
+{
+ return unlikely(tif_need_resched());
+}
+static inline bool __must_check current_clr_polling_and_test(void)
+{
+ return unlikely(tif_need_resched());
+}
#endif
/*
diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index a629e4b23217..fddbe2023a5d 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -118,6 +118,8 @@ static inline __deprecated void set_need_resched(void)
*/
}
+#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
+
#if defined TIF_RESTORE_SIGMASK && !defined HAVE_SET_RESTORE_SIGMASK
/*
* An arch can define its own version of set_restore_sigmask() to get the
diff --git a/kernel/cpu/idle.c b/kernel/cpu/idle.c
index e695c0a0bcb5..c261409500e4 100644
--- a/kernel/cpu/idle.c
+++ b/kernel/cpu/idle.c
@@ -44,7 +44,7 @@ static inline int cpu_idle_poll(void)
rcu_idle_enter();
trace_cpu_idle_rcuidle(0, smp_processor_id());
local_irq_enable();
- while (!need_resched())
+ while (!tif_need_resched())
cpu_relax();
trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
rcu_idle_exit();
@@ -92,8 +92,7 @@ static void cpu_idle_loop(void)
if (cpu_idle_force_poll || tick_check_broadcast_expired()) {
cpu_idle_poll();
} else {
- current_clr_polling();
- if (!need_resched()) {
+ if (!current_clr_polling_and_test()) {
stop_critical_timings();
rcu_idle_enter();
arch_cpu_idle();
@@ -103,7 +102,7 @@ static void cpu_idle_loop(void)
} else {
local_irq_enable();
}
- current_set_polling();
+ __current_set_polling();
}
arch_cpu_idle_exit();
}
@@ -129,7 +128,7 @@ void cpu_startup_entry(enum cpuhp_state state)
*/
boot_init_stack_canary();
#endif
- current_set_polling();
+ __current_set_polling();
arch_cpu_idle_prepare();
cpu_idle_loop();
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-20 03:59:38 +0000