diff options
| -rw-r--r-- | kernel/time/sched_clock.c | 38 |
1 files changed, 21 insertions, 17 deletions
diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c index 396f7b9dccc9..c018ffc59937 100644 --- a/kernel/time/sched_clock.c +++ b/kernel/time/sched_clock.c @@ -8,15 +8,17 @@ #include <linux/clocksource.h> #include <linux/init.h> #include <linux/jiffies.h> +#include <linux/ktime.h> #include <linux/kernel.h> #include <linux/moduleparam.h> #include <linux/sched.h> #include <linux/syscore_ops.h> -#include <linux/timer.h> +#include <linux/hrtimer.h> #include <linux/sched_clock.h> #include <linux/seqlock.h> struct clock_data { + ktime_t wrap_kt; u64 epoch_ns; u32 epoch_cyc; seqcount_t seq; @@ -26,8 +28,7 @@ struct clock_data { bool suspended; }; -static void sched_clock_poll(unsigned long wrap_ticks); -static DEFINE_TIMER(sched_clock_timer, sched_clock_poll, 0, 0); +static struct hrtimer sched_clock_timer; static int irqtime = -1; core_param(irqtime, irqtime, int, 0400); @@ -93,15 +94,16 @@ static void notrace update_sched_clock(void) raw_local_irq_restore(flags); } -static void sched_clock_poll(unsigned long wrap_ticks) +static enum hrtimer_restart sched_clock_poll(struct hrtimer *hrt) { - mod_timer(&sched_clock_timer, round_jiffies(jiffies + wrap_ticks)); update_sched_clock(); + hrtimer_forward_now(hrt, cd.wrap_kt); + return HRTIMER_RESTART; } void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate) { - unsigned long r, w; + unsigned long r; u64 res, wrap; char r_unit; @@ -129,19 +131,13 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate) /* calculate how many ns until we wrap */ wrap = cyc_to_ns((1ULL << bits) - 1, cd.mult, cd.shift); - do_div(wrap, NSEC_PER_MSEC); - w = wrap; + cd.wrap_kt = ns_to_ktime(wrap - (wrap >> 3)); /* calculate the ns resolution of this counter */ res = cyc_to_ns(1ULL, cd.mult, cd.shift); - pr_info("sched_clock: %u bits at %lu%cHz, resolution %lluns, wraps every %lums\n", - bits, r, r_unit, res, w); + pr_info("sched_clock: %u bits at %lu%cHz, resolution %lluns, wraps every %lluns\n", + bits, r, r_unit, res, wrap); - /* - * Start the timer to keep sched_clock() properly updated and - * sets the initial epoch. - */ - sched_clock_timer.data = msecs_to_jiffies(w - (w / 10)); update_sched_clock(); /* @@ -172,12 +168,20 @@ void __init sched_clock_postinit(void) if (read_sched_clock == jiffy_sched_clock_read) setup_sched_clock(jiffy_sched_clock_read, 32, HZ); - sched_clock_poll(sched_clock_timer.data); + update_sched_clock(); + + /* + * Start the timer to keep sched_clock() properly updated and + * sets the initial epoch. + */ + hrtimer_init(&sched_clock_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + sched_clock_timer.function = sched_clock_poll; + hrtimer_start(&sched_clock_timer, cd.wrap_kt, HRTIMER_MODE_REL); } static int sched_clock_suspend(void) { - sched_clock_poll(sched_clock_timer.data); + sched_clock_poll(&sched_clock_timer); cd.suspended = true; return 0; } |