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authorMathieu Desnoyers <mathieu.desnoyers@efficios.com>2011-03-16 19:05:31 -0400
committerMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>2011-03-16 19:05:31 -0400
commit6b5e84f4cdffd8eb44cc400e1f6243cdc6662fd5 (patch)
tree5b3902f56424d9626a75418e556c288b064df395 /arch/x86/kernel/process_32.c
parent9cf695f37cd70bbcb26cf14693267955b74ae97e (diff)
downloadlinux-linaro-android-6b5e84f4cdffd8eb44cc400e1f6243cdc6662fd5.tar.gz
idle-notifier-x86_32
idle notifier standardization x86_32 Add idle notifier callback to x86_32. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Diffstat (limited to 'arch/x86/kernel/process_32.c')
-rw-r--r--arch/x86/kernel/process_32.c32
1 files changed, 32 insertions, 0 deletions
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 8d128783af4..f580a4332f8 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -38,6 +38,8 @@
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/kdebug.h>
+#include <linux/notifier.h>
+#include <linux/idle.h>
#include <asm/pgtable.h>
#include <asm/system.h>
@@ -59,6 +61,30 @@
asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
+static DEFINE_PER_CPU(unsigned char, is_idle);
+
+void enter_idle(void)
+{
+ percpu_write(is_idle, 1);
+ notify_idle(IDLE_START);
+}
+
+static void __exit_idle(void)
+{
+ if (x86_test_and_clear_bit_percpu(0, is_idle) == 0)
+ return;
+ notify_idle(IDLE_END);
+}
+
+/* Called from interrupts to signify idle end */
+void exit_idle(void)
+{
+ /* idle loop has pid 0 */
+ if (current->pid)
+ return;
+ __exit_idle();
+}
+
/*
* Return saved PC of a blocked thread.
*/
@@ -107,10 +133,16 @@ void cpu_idle(void)
play_dead();
local_irq_disable();
+ enter_idle();
/* Don't trace irqs off for idle */
stop_critical_timings();
pm_idle();
start_critical_timings();
+
+ /* 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();
}
tick_nohz_restart_sched_tick();
preempt_enable_no_resched();