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authorLinus Torvalds <torvalds@linux-foundation.org>2013-04-30 07:50:17 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-04-30 07:50:17 -0700
commit8700c95adb033843fc163d112b9d21d4fda78018 (patch)
tree7bb9a37b8fe6328f63a61d88063c556346001098 /arch/x86
parent16fa94b532b1958f508e07eca1a9256351241fbc (diff)
parentd190e8195b90bc1e65c494fe08e54e9e581bfd16 (diff)
downloadlinux-8700c95adb033843fc163d112b9d21d4fda78018.tar.gz
Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull SMP/hotplug changes from Ingo Molnar: "This is a pretty large, multi-arch series unifying and generalizing the various disjunct pieces of idle routines that architectures have historically copied from each other and have grown in random, wildly inconsistent and sometimes buggy directions: 101 files changed, 455 insertions(+), 1328 deletions(-) this went through a number of review and test iterations before it was committed, it was tested on various architectures, was exposed to linux-next for quite some time - nevertheless it might cause problems on architectures that don't read the mailing lists and don't regularly test linux-next. This cat herding excercise was motivated by the -rt kernel, and was brought to you by Thomas "the Whip" Gleixner." * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits) idle: Remove GENERIC_IDLE_LOOP config switch um: Use generic idle loop ia64: Make sure interrupts enabled when we "safe_halt()" sparc: Use generic idle loop idle: Remove unused ARCH_HAS_DEFAULT_IDLE bfin: Fix typo in arch_cpu_idle() xtensa: Use generic idle loop x86: Use generic idle loop unicore: Use generic idle loop tile: Use generic idle loop tile: Enter idle with preemption disabled sh: Use generic idle loop score: Use generic idle loop s390: Use generic idle loop powerpc: Use generic idle loop parisc: Use generic idle loop openrisc: Use generic idle loop mn10300: Use generic idle loop mips: Use generic idle loop microblaze: Use generic idle loop ...
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/Kconfig3
-rw-r--r--arch/x86/include/asm/thread_info.h2
-rw-r--r--arch/x86/kernel/process.c105
-rw-r--r--arch/x86/kernel/smpboot.c2
-rw-r--r--arch/x86/xen/smp.c2
5 files changed, 29 insertions, 85 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 15b5cef4aa3..d75b48c11be 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -188,9 +188,6 @@ config GENERIC_CALIBRATE_DELAY
config ARCH_HAS_CPU_RELAX
def_bool y
-config ARCH_HAS_DEFAULT_IDLE
- def_bool y
-
config ARCH_HAS_CACHE_LINE_SIZE
def_bool y
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index 2cd056e3ada..a1df6e84691 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -241,8 +241,6 @@ static inline struct thread_info *current_thread_info(void)
skip sending interrupt */
#define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */
-#define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
-
#ifndef __ASSEMBLY__
#define HAVE_SET_RESTORE_SIGMASK 1
static inline void set_restore_sigmask(void)
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 14ae10031ff..6833bffaadb 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -301,13 +301,7 @@ void exit_idle(void)
}
#endif
-/*
- * The idle thread. There's no useful work to be
- * done, so just try to conserve power and have a
- * low exit latency (ie sit in a loop waiting for
- * somebody to say that they'd like to reschedule)
- */
-void cpu_idle(void)
+void arch_cpu_idle_prepare(void)
{
/*
* If we're the non-boot CPU, nothing set the stack canary up
@@ -317,71 +311,40 @@ void cpu_idle(void)
* canaries already on the stack wont ever trigger).
*/
boot_init_stack_canary();
- current_thread_info()->status |= TS_POLLING;
-
- while (1) {
- tick_nohz_idle_enter();
-
- while (!need_resched()) {
- rmb();
-
- if (cpu_is_offline(smp_processor_id()))
- play_dead();
-
- /*
- * Idle routines should keep interrupts disabled
- * from here on, until they go to idle.
- * Otherwise, idle callbacks can misfire.
- */
- local_touch_nmi();
- local_irq_disable();
-
- enter_idle();
-
- /* Don't trace irqs off for idle */
- stop_critical_timings();
-
- /* enter_idle() needs rcu for notifiers */
- rcu_idle_enter();
+}
- if (cpuidle_idle_call())
- x86_idle();
+void arch_cpu_idle_enter(void)
+{
+ local_touch_nmi();
+ enter_idle();
+}
- rcu_idle_exit();
- start_critical_timings();
+void arch_cpu_idle_exit(void)
+{
+ __exit_idle();
+}
- /* In many cases the interrupt that ended idle
- has already called exit_idle. But some idle
- loops can be woken up without interrupt. */
- __exit_idle();
- }
+void arch_cpu_idle_dead(void)
+{
+ play_dead();
+}
- tick_nohz_idle_exit();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
- }
+/*
+ * Called from the generic idle code.
+ */
+void arch_cpu_idle(void)
+{
+ if (cpuidle_idle_call())
+ x86_idle();
}
/*
- * We use this if we don't have any better
- * idle routine..
+ * We use this if we don't have any better idle routine..
*/
void default_idle(void)
{
trace_cpu_idle_rcuidle(1, smp_processor_id());
- current_thread_info()->status &= ~TS_POLLING;
- /*
- * TS_POLLING-cleared state must be visible before we
- * test NEED_RESCHED:
- */
- smp_mb();
-
- if (!need_resched())
- safe_halt(); /* enables interrupts racelessly */
- else
- local_irq_enable();
- current_thread_info()->status |= TS_POLLING;
+ safe_halt();
trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
}
#ifdef CONFIG_APM_MODULE
@@ -411,20 +374,6 @@ void stop_this_cpu(void *dummy)
halt();
}
-/*
- * On SMP it's slightly faster (but much more power-consuming!)
- * to poll the ->work.need_resched flag instead of waiting for the
- * cross-CPU IPI to arrive. Use this option with caution.
- */
-static void poll_idle(void)
-{
- trace_cpu_idle_rcuidle(0, smp_processor_id());
- local_irq_enable();
- while (!need_resched())
- cpu_relax();
- trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
-}
-
bool amd_e400_c1e_detected;
EXPORT_SYMBOL(amd_e400_c1e_detected);
@@ -489,10 +438,10 @@ static void amd_e400_idle(void)
void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
{
#ifdef CONFIG_SMP
- if (x86_idle == poll_idle && smp_num_siblings > 1)
+ if (boot_option_idle_override == IDLE_POLL && smp_num_siblings > 1)
pr_warn_once("WARNING: polling idle and HT enabled, performance may degrade\n");
#endif
- if (x86_idle)
+ if (x86_idle || boot_option_idle_override == IDLE_POLL)
return;
if (cpu_has_amd_erratum(amd_erratum_400)) {
@@ -517,8 +466,8 @@ static int __init idle_setup(char *str)
if (!strcmp(str, "poll")) {
pr_info("using polling idle threads\n");
- x86_idle = poll_idle;
boot_option_idle_override = IDLE_POLL;
+ cpu_idle_poll_ctrl(true);
} else if (!strcmp(str, "halt")) {
/*
* When the boot option of idle=halt is added, halt is
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 9f190a2a00e..9c73b51817e 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -284,7 +284,7 @@ notrace static void __cpuinit start_secondary(void *unused)
x86_cpuinit.setup_percpu_clockev();
wmb();
- cpu_idle();
+ cpu_startup_entry(CPUHP_ONLINE);
}
void __init smp_store_boot_cpu_info(void)
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 0d466d7c717..8ff37995d54 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -95,7 +95,7 @@ static void __cpuinit cpu_bringup(void)
static void __cpuinit cpu_bringup_and_idle(void)
{
cpu_bringup();
- cpu_idle();
+ cpu_startup_entry(CPUHP_ONLINE);
}
static int xen_smp_intr_init(unsigned int cpu)