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-rw-r--r--arch/arm/kernel/sched_clock.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/arm/kernel/sched_clock.c b/arch/arm/kernel/sched_clock.c
index 27d186abbc0..fc6692e2b60 100644
--- a/arch/arm/kernel/sched_clock.c
+++ b/arch/arm/kernel/sched_clock.c
@@ -9,6 +9,7 @@
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
+#include <linux/moduleparam.h>
#include <linux/sched.h>
#include <linux/syscore_ops.h>
#include <linux/timer.h>
@@ -21,10 +22,15 @@ struct clock_data {
u32 epoch_cyc_copy;
u32 mult;
u32 shift;
+ bool suspended;
+ bool needs_suspend;
};
static void sched_clock_poll(unsigned long wrap_ticks);
static DEFINE_TIMER(sched_clock_timer, sched_clock_poll, 0, 0);
+static int irqtime = -1;
+
+core_param(irqtime, irqtime, int, 0400);
static struct clock_data cd = {
.mult = NSEC_PER_SEC / HZ,
@@ -49,6 +55,9 @@ static unsigned long long cyc_to_sched_clock(u32 cyc, u32 mask)
u64 epoch_ns;
u32 epoch_cyc;
+ if (cd.suspended)
+ return cd.epoch_ns;
+
/*
* Load the epoch_cyc and epoch_ns atomically. We do this by
* ensuring that we always write epoch_cyc, epoch_ns and
@@ -145,6 +154,10 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate)
*/
cd.epoch_ns = 0;
+ /* Enable IRQ time accounting if we have a fast enough sched_clock */
+ if (irqtime > 0 || (irqtime == -1 && rate >= 1000000))
+ enable_sched_clock_irqtime();
+
pr_debug("Registered %pF as sched_clock source\n", read);
}
@@ -169,11 +182,20 @@ void __init sched_clock_postinit(void)
static int sched_clock_suspend(void)
{
sched_clock_poll(sched_clock_timer.data);
+ cd.suspended = true;
return 0;
}
+static void sched_clock_resume(void)
+{
+ cd.epoch_cyc = read_sched_clock();
+ cd.epoch_cyc_copy = cd.epoch_cyc;
+ cd.suspended = false;
+}
+
static struct syscore_ops sched_clock_ops = {
.suspend = sched_clock_suspend,
+ .resume = sched_clock_resume,
};
static int __init sched_clock_syscore_init(void)