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hangcheck-timer: Use ktime_get_ns()

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There is no point in having a S390 private implementation and there is
no point in using the raw monotonic time. The NTP freqeuency
adjustment of CLOCK_MONOTONIC is really not doing any harm for the
hang check timer.

Use ktime_get_ns() for everything and get rid of the timespec
conversions.

V2: Drop the raw monotonic and the S390 special case

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
This commit is contained in:
Thomas Gleixner
2014-07-16 21:05:03 +00:00
committed by John Stultz
parent 61edec81d2
commit 2044fdb03e
1 changed files with 5 additions and 28 deletions
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31
drivers/char/hangcheck-timer.c
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@@ -49,7 +49,7 @@
#include <asm/uaccess.h> #include <asm/uaccess.h>
#include <linux/sysrq.h> #include <linux/sysrq.h>
#include <linux/timer.h> #include <linux/timer.h>
#include <linux/time.h> #include <linux/hrtimer.h>
#define VERSION_STR "0.9.1" #define VERSION_STR "0.9.1"
@@ -117,24 +117,7 @@ __setup("hcheck_reboot", hangcheck_parse_reboot);
__setup("hcheck_dump_tasks", hangcheck_parse_dump_tasks); __setup("hcheck_dump_tasks", hangcheck_parse_dump_tasks);
#endif /* not MODULE */ #endif /* not MODULE */
#if defined(CONFIG_S390)
# define HAVE_MONOTONIC
#define TIMER_FREQ 1000000000ULL #define TIMER_FREQ 1000000000ULL
#else
# define TIMER_FREQ 1000000000ULL
#endif
#ifdef HAVE_MONOTONIC
extern unsigned long long monotonic_clock(void);
#else
static inline unsigned long long monotonic_clock(void)
{
struct timespec ts;
getrawmonotonic(&ts);
return timespec_to_ns(&ts);
}
#endif /* HAVE_MONOTONIC */
/* Last time scheduled */ /* Last time scheduled */
static unsigned long long hangcheck_tsc, hangcheck_tsc_margin; static unsigned long long hangcheck_tsc, hangcheck_tsc_margin;
@@ -143,12 +126,11 @@ static void hangcheck_fire(unsigned long);
static DEFINE_TIMER(hangcheck_ticktock, hangcheck_fire, 0, 0); static DEFINE_TIMER(hangcheck_ticktock, hangcheck_fire, 0, 0);
static void hangcheck_fire(unsigned long data) static void hangcheck_fire(unsigned long data)
{ {
unsigned long long cur_tsc, tsc_diff; unsigned long long cur_tsc, tsc_diff;
cur_tsc = monotonic_clock(); cur_tsc = ktime_get_ns();
if (cur_tsc > hangcheck_tsc) if (cur_tsc > hangcheck_tsc)
tsc_diff = cur_tsc - hangcheck_tsc; tsc_diff = cur_tsc - hangcheck_tsc;
@@ -177,7 +159,7 @@ static void hangcheck_fire(unsigned long data)
tsc_diff, tsc_diff - hangcheck_tick*TIMER_FREQ); tsc_diff, tsc_diff - hangcheck_tick*TIMER_FREQ);
#endif #endif
mod_timer(&hangcheck_ticktock, jiffies + (hangcheck_tick*HZ)); mod_timer(&hangcheck_ticktock, jiffies + (hangcheck_tick*HZ));
hangcheck_tsc = monotonic_clock(); hangcheck_tsc = ktime_get_ns();
} }
@@ -185,16 +167,11 @@ static int __init hangcheck_init(void)
{ {
printk("Hangcheck: starting hangcheck timer %s (tick is %d seconds, margin is %d seconds).\n", printk("Hangcheck: starting hangcheck timer %s (tick is %d seconds, margin is %d seconds).\n",
VERSION_STR, hangcheck_tick, hangcheck_margin); VERSION_STR, hangcheck_tick, hangcheck_margin);
#if defined (HAVE_MONOTONIC)
printk("Hangcheck: Using monotonic_clock().\n");
#else
printk("Hangcheck: Using getrawmonotonic().\n");
#endif /* HAVE_MONOTONIC */
hangcheck_tsc_margin = hangcheck_tsc_margin =
(unsigned long long)(hangcheck_margin + hangcheck_tick); (unsigned long long)(hangcheck_margin + hangcheck_tick);
hangcheck_tsc_margin *= (unsigned long long)TIMER_FREQ; hangcheck_tsc_margin *= (unsigned long long)TIMER_FREQ;
hangcheck_tsc = monotonic_clock(); hangcheck_tsc = ktime_get_ns();
mod_timer(&hangcheck_ticktock, jiffies + (hangcheck_tick*HZ)); mod_timer(&hangcheck_ticktock, jiffies + (hangcheck_tick*HZ));
return 0; return 0;