Re: [PATCH] Introduce boot based time
On Thu, 10 May 2007 19:10:25 +0200
Tomas Janousek <[EMAIL PROTECTED]> wrote:
> The commits
> 411187fb05cd11676b0979d9fbf3291db69dbce2 (GTOD: persistent clock support)
> c1d370e167d66b10bca3b602d3740405469383de (i386: use GTOD persistent clock
> support)
> changed the monotonic time so that it no longer jumps after resume, but it's
> not possible to use it for boot time and process start time calculations then.
> Also, the uptime no longer increases during suspend.
>
> I add a variable to track the wall_to_monotonic changes, a function to get the
> real boot time and a function to get the boot based time from the monotonic
> one.
From: Andrew Morton <[EMAIL PROTECTED]>
- I don't think those sybols are needed in modules.
- Document total_sleep_time units (would have been better to call it
total_sleep_time_secs, perhaps).
Cc: John Stultz <[EMAIL PROTECTED]>
Cc: Tomas Janousek <[EMAIL PROTECTED]>
Cc: Tomas Smetana <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
---
kernel/time/timekeeping.c |6 +-
1 files changed, 1 insertion(+), 5 deletions(-)
diff -puN include/linux/time.h~introduce-boot-based-time-fix
include/linux/time.h
diff -puN kernel/time/timekeeping.c~introduce-boot-based-time-fix
kernel/time/timekeeping.c
--- a/kernel/time/timekeeping.c~introduce-boot-based-time-fix
+++ a/kernel/time/timekeeping.c
@@ -46,7 +46,7 @@ EXPORT_SYMBOL(xtime_lock);
*/
struct timespec xtime __attribute__ ((aligned (16)));
struct timespec wall_to_monotonic __attribute__ ((aligned (16)));
-static unsigned long total_sleep_time;
+static unsigned long total_sleep_time; /* seconds */
EXPORT_SYMBOL(xtime);
@@ -503,8 +503,6 @@ void getboottime(struct timespec *ts)
- wall_to_monotonic.tv_nsec);
}
-EXPORT_SYMBOL(getboottime);
-
/**
* monotonic_to_bootbased - Convert the monotonic time to boot based.
* @ts:pointer to the timespec to be converted
@@ -513,5 +511,3 @@ void monotonic_to_bootbased(struct times
{
ts->tv_sec += total_sleep_time;
}
-
-EXPORT_SYMBOL(monotonic_to_bootbased);
_
-
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Re: [PATCH] Introduce boot based time
Hi John and Tomas, On Thursday 10 May 2007, john stultz wrote: > I'm not sure I follow this. > > total_sleep_time stores seconds. So on 32bit systems that's 130some > years, so it shouldn't be an issue. > > Is the reason you want it to be a ktime is because you want a way to > keep sub-second sleep granularity? No, I'm just overworked and getting sloppy :-/ Sorry for the noise... Best regards Ingo Oeser - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] Introduce boot based time
On Thu, 2007-05-10 at 21:48 +0200, Ingo Oeser wrote: > Hi Tomas, > > On Thursday 10 May 2007, Tomas Janousek wrote: > > diff --git a/include/linux/time.h b/include/linux/time.h > > index 8997b61..06f3eaf 100644 > > --- a/include/linux/time.h > > +++ b/include/linux/time.h > > @@ -116,6 +116,8 @@ extern int do_setitimer(int which, struct itimerval > > *value, > > extern unsigned int alarm_setitimer(unsigned int seconds); > > extern int do_getitimer(int which, struct itimerval *value); > > extern void getnstimeofday(struct timespec *tv); > > +extern void getboottime(struct timespec *ts); > > +extern void monotonic_to_bootbased(struct timespec *ts); > > > > extern struct timespec timespec_trunc(struct timespec t, unsigned gran); > > extern int timekeeping_is_continuous(void); > > diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c > > index f9217bf..dd9647a 100644 > > --- a/kernel/time/timekeeping.c > > +++ b/kernel/time/timekeeping.c > > @@ -36,9 +36,17 @@ EXPORT_SYMBOL(xtime_lock); > > * at zero at system boot time, so wall_to_monotonic will be negative, > > * however, we will ALWAYS keep the tv_nsec part positive so we can use > > * the usual normalization. > > + * > > + * wall_to_monotonic is moved after resume from suspend for the monotonic > > + * time not to jump. We need to add total_sleep_time to wall_to_monotonic > > + * to get the real boot based time offset. > > + * > > + * - wall_to_monotonic is no longer the boot time, getboottime must be > > + * used instead. > > */ > > struct timespec xtime __attribute__ ((aligned (16))); > > struct timespec wall_to_monotonic __attribute__ ((aligned (16))); > > +static unsigned long total_sleep_time; > > Could you make that a ktime_t (or struct ktime)? > There are machines, which sleep more than they are awake. > Just imagine a surveillance camera triggered by door entrance. > > Yes, these things might run Linux (e.g. on "cris" architecture). > > Or your VCR. > Yes, these devices might sleep more than they are awake, > if you are not a TV junkie :-) I'm not sure I follow this. total_sleep_time stores seconds. So on 32bit systems that's 130some years, so it shouldn't be an issue. Is the reason you want it to be a ktime is because you want a way to keep sub-second sleep granularity? thanks -john - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] Introduce boot based time
Hi Ingo, On Thu, May 10, 2007 at 09:48:59PM +0200, Ingo Oeser wrote: > > +static unsigned long total_sleep_time; > > Could you make that a ktime_t (or struct ktime)? > There are machines, which sleep more than they are awake. > Just imagine a surveillance camera triggered by door entrance. > > Yes, these things might run Linux (e.g. on "cris" architecture). > > Or your VCR. > Yes, these devices might sleep more than they are awake, > if you are not a TV junkie :-) The value is in seconds. It can hold up to 136 years of sleep. I'd rather spend the money on beer than on a VCR that I'm gonna suspend for 137 years :) (or do we have a 16-bit long anywhere?) Regards, -- TJ. (Brno, CZ), BaseOS, Red Hat - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] Introduce boot based time
Hi Tomas, On Thursday 10 May 2007, Tomas Janousek wrote: > diff --git a/include/linux/time.h b/include/linux/time.h > index 8997b61..06f3eaf 100644 > --- a/include/linux/time.h > +++ b/include/linux/time.h > @@ -116,6 +116,8 @@ extern int do_setitimer(int which, struct itimerval > *value, > extern unsigned int alarm_setitimer(unsigned int seconds); > extern int do_getitimer(int which, struct itimerval *value); > extern void getnstimeofday(struct timespec *tv); > +extern void getboottime(struct timespec *ts); > +extern void monotonic_to_bootbased(struct timespec *ts); > > extern struct timespec timespec_trunc(struct timespec t, unsigned gran); > extern int timekeeping_is_continuous(void); > diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c > index f9217bf..dd9647a 100644 > --- a/kernel/time/timekeeping.c > +++ b/kernel/time/timekeeping.c > @@ -36,9 +36,17 @@ EXPORT_SYMBOL(xtime_lock); > * at zero at system boot time, so wall_to_monotonic will be negative, > * however, we will ALWAYS keep the tv_nsec part positive so we can use > * the usual normalization. > + * > + * wall_to_monotonic is moved after resume from suspend for the monotonic > + * time not to jump. We need to add total_sleep_time to wall_to_monotonic > + * to get the real boot based time offset. > + * > + * - wall_to_monotonic is no longer the boot time, getboottime must be > + * used instead. > */ > struct timespec xtime __attribute__ ((aligned (16))); > struct timespec wall_to_monotonic __attribute__ ((aligned (16))); > +static unsigned long total_sleep_time; Could you make that a ktime_t (or struct ktime)? There are machines, which sleep more than they are awake. Just imagine a surveillance camera triggered by door entrance. Yes, these things might run Linux (e.g. on "cris" architecture). Or your VCR. Yes, these devices might sleep more than they are awake, if you are not a TV junkie :-) Best regards Ingo Oeser - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] Introduce boot based time
On Thu, 2007-05-10 at 19:10 +0200, Tomas Janousek wrote:
> The commits
> 411187fb05cd11676b0979d9fbf3291db69dbce2 (GTOD: persistent clock support)
> c1d370e167d66b10bca3b602d3740405469383de (i386: use GTOD persistent clock
> support)
> changed the monotonic time so that it no longer jumps after resume, but it's
> not possible to use it for boot time and process start time calculations then.
> Also, the uptime no longer increases during suspend.
>
> I add a variable to track the wall_to_monotonic changes, a function to get the
> real boot time and a function to get the boot based time from the monotonic
> one.
>
> Signed-off-by: Tomas Janousek <[EMAIL PROTECTED]>
> Cc: Tomas Smetana <[EMAIL PROTECTED]>
> Cc: John Stultz <[EMAIL PROTECTED]>
Looks good! Thanks again for catching this!
Acked-by: John Stultz <[EMAIL PROTECTED]>
> ---
> include/linux/time.h |2 ++
> kernel/time/timekeeping.c | 41 +
> 2 files changed, 43 insertions(+), 0 deletions(-)
>
> diff --git a/include/linux/time.h b/include/linux/time.h
> index 8997b61..06f3eaf 100644
> --- a/include/linux/time.h
> +++ b/include/linux/time.h
> @@ -116,6 +116,8 @@ extern int do_setitimer(int which, struct itimerval
> *value,
> extern unsigned int alarm_setitimer(unsigned int seconds);
> extern int do_getitimer(int which, struct itimerval *value);
> extern void getnstimeofday(struct timespec *tv);
> +extern void getboottime(struct timespec *ts);
> +extern void monotonic_to_bootbased(struct timespec *ts);
>
> extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
> extern int timekeeping_is_continuous(void);
> diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
> index f9217bf..dd9647a 100644
> --- a/kernel/time/timekeeping.c
> +++ b/kernel/time/timekeeping.c
> @@ -36,9 +36,17 @@ EXPORT_SYMBOL(xtime_lock);
> * at zero at system boot time, so wall_to_monotonic will be negative,
> * however, we will ALWAYS keep the tv_nsec part positive so we can use
> * the usual normalization.
> + *
> + * wall_to_monotonic is moved after resume from suspend for the monotonic
> + * time not to jump. We need to add total_sleep_time to wall_to_monotonic
> + * to get the real boot based time offset.
> + *
> + * - wall_to_monotonic is no longer the boot time, getboottime must be
> + * used instead.
> */
> struct timespec xtime __attribute__ ((aligned (16)));
> struct timespec wall_to_monotonic __attribute__ ((aligned (16)));
> +static unsigned long total_sleep_time;
>
> EXPORT_SYMBOL(xtime);
>
> @@ -251,6 +259,7 @@ void __init timekeeping_init(void)
> xtime.tv_nsec = 0;
> set_normalized_timespec(&wall_to_monotonic,
> -xtime.tv_sec, -xtime.tv_nsec);
> + total_sleep_time = 0;
>
> write_sequnlock_irqrestore(&xtime_lock, flags);
> }
> @@ -280,6 +289,7 @@ static int timekeeping_resume(struct sys_device *dev)
>
> xtime.tv_sec += sleep_length;
> wall_to_monotonic.tv_sec -= sleep_length;
> + total_sleep_time += sleep_length;
> }
> /* re-base the last cycle value */
> clock->cycle_last = clocksource_read(clock);
> @@ -474,3 +484,34 @@ void update_wall_time(void)
> change_clocksource();
> update_vsyscall(&xtime, clock);
> }
> +
> +/**
> + * getboottime - Return the real time of system boot.
> + * @ts: pointer to the timespec to be set
> + *
> + * Returns the time of day in a timespec.
> + *
> + * This is based on the wall_to_monotonic offset and the total suspend
> + * time. Calls to settimeofday will affect the value returned (which
> + * basically means that however wrong your real time clock is at boot time,
> + * you get the right time here).
> + */
> +void getboottime(struct timespec *ts)
> +{
> + set_normalized_timespec(ts,
> + - (wall_to_monotonic.tv_sec + total_sleep_time),
> + - wall_to_monotonic.tv_nsec);
> +}
> +
> +EXPORT_SYMBOL(getboottime);
> +
> +/**
> + * monotonic_to_bootbased - Convert the monotonic time to boot based.
> + * @ts: pointer to the timespec to be converted
> + */
> +void monotonic_to_bootbased(struct timespec *ts)
> +{
> + ts->tv_sec += total_sleep_time;
> +}
> +
> +EXPORT_SYMBOL(monotonic_to_bootbased);
> --
> 1.5.1.4
>
>
-
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[PATCH] Introduce boot based time
The commits
411187fb05cd11676b0979d9fbf3291db69dbce2 (GTOD: persistent clock support)
c1d370e167d66b10bca3b602d3740405469383de (i386: use GTOD persistent clock
support)
changed the monotonic time so that it no longer jumps after resume, but it's
not possible to use it for boot time and process start time calculations then.
Also, the uptime no longer increases during suspend.
I add a variable to track the wall_to_monotonic changes, a function to get the
real boot time and a function to get the boot based time from the monotonic
one.
Signed-off-by: Tomas Janousek <[EMAIL PROTECTED]>
Cc: Tomas Smetana <[EMAIL PROTECTED]>
Cc: John Stultz <[EMAIL PROTECTED]>
---
include/linux/time.h |2 ++
kernel/time/timekeeping.c | 41 +
2 files changed, 43 insertions(+), 0 deletions(-)
diff --git a/include/linux/time.h b/include/linux/time.h
index 8997b61..06f3eaf 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -116,6 +116,8 @@ extern int do_setitimer(int which, struct itimerval *value,
extern unsigned int alarm_setitimer(unsigned int seconds);
extern int do_getitimer(int which, struct itimerval *value);
extern void getnstimeofday(struct timespec *tv);
+extern void getboottime(struct timespec *ts);
+extern void monotonic_to_bootbased(struct timespec *ts);
extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
extern int timekeeping_is_continuous(void);
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index f9217bf..dd9647a 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -36,9 +36,17 @@ EXPORT_SYMBOL(xtime_lock);
* at zero at system boot time, so wall_to_monotonic will be negative,
* however, we will ALWAYS keep the tv_nsec part positive so we can use
* the usual normalization.
+ *
+ * wall_to_monotonic is moved after resume from suspend for the monotonic
+ * time not to jump. We need to add total_sleep_time to wall_to_monotonic
+ * to get the real boot based time offset.
+ *
+ * - wall_to_monotonic is no longer the boot time, getboottime must be
+ * used instead.
*/
struct timespec xtime __attribute__ ((aligned (16)));
struct timespec wall_to_monotonic __attribute__ ((aligned (16)));
+static unsigned long total_sleep_time;
EXPORT_SYMBOL(xtime);
@@ -251,6 +259,7 @@ void __init timekeeping_init(void)
xtime.tv_nsec = 0;
set_normalized_timespec(&wall_to_monotonic,
-xtime.tv_sec, -xtime.tv_nsec);
+ total_sleep_time = 0;
write_sequnlock_irqrestore(&xtime_lock, flags);
}
@@ -280,6 +289,7 @@ static int timekeeping_resume(struct sys_device *dev)
xtime.tv_sec += sleep_length;
wall_to_monotonic.tv_sec -= sleep_length;
+ total_sleep_time += sleep_length;
}
/* re-base the last cycle value */
clock->cycle_last = clocksource_read(clock);
@@ -474,3 +484,34 @@ void update_wall_time(void)
change_clocksource();
update_vsyscall(&xtime, clock);
}
+
+/**
+ * getboottime - Return the real time of system boot.
+ * @ts:pointer to the timespec to be set
+ *
+ * Returns the time of day in a timespec.
+ *
+ * This is based on the wall_to_monotonic offset and the total suspend
+ * time. Calls to settimeofday will affect the value returned (which
+ * basically means that however wrong your real time clock is at boot time,
+ * you get the right time here).
+ */
+void getboottime(struct timespec *ts)
+{
+ set_normalized_timespec(ts,
+ - (wall_to_monotonic.tv_sec + total_sleep_time),
+ - wall_to_monotonic.tv_nsec);
+}
+
+EXPORT_SYMBOL(getboottime);
+
+/**
+ * monotonic_to_bootbased - Convert the monotonic time to boot based.
+ * @ts:pointer to the timespec to be converted
+ */
+void monotonic_to_bootbased(struct timespec *ts)
+{
+ ts->tv_sec += total_sleep_time;
+}
+
+EXPORT_SYMBOL(monotonic_to_bootbased);
--
1.5.1.4
--
TJ. (Brno, CZ), BaseOS, Red Hat
-
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