* [PATCH v2 0/2] clocksource: don't suspend/resume when unused
@ 2015-01-16 16:57 ` Alexandre Belloni
0 siblings, 0 replies; 16+ messages in thread
From: Alexandre Belloni @ 2015-01-16 16:57 UTC (permalink / raw)
To: Thomas Gleixner
Cc: John Stultz, Daniel Lezcano, Nicolas Ferre, Boris Brezillon,
Russell King - ARM Linux, linux-arm-kernel, linux-kernel,
Alexandre Belloni
This is a quite naive implementation to track whether a clocksource is enabled.
I chose not to add a member in struct clocksource and use a flag instead.
I found that timekeeping.c is the only consumer for clocksource and I converted
it to use clocksource_enable and clocksource_disable.
Changes in v2:
- removed the check on enable in timekeeping.c to ensure all clocksources are
going through clocksource_enable
- rework clocksource_enable to set CLOCK_SOURCE_USED when enable is successful
if present
Alexandre Belloni (2):
clocksource: track usage
clocksource: don't suspend/resume when unused
include/linux/clocksource.h | 4 ++++
kernel/time/clocksource.c | 34 ++++++++++++++++++++++++++++++++--
kernel/time/timekeeping.c | 8 +++-----
3 files changed, 39 insertions(+), 7 deletions(-)
--
2.1.0
^ permalink raw reply [flat|nested] 16+ messages in thread
* [PATCH v2 0/2] clocksource: don't suspend/resume when unused
@ 2015-01-16 16:57 ` Alexandre Belloni
0 siblings, 0 replies; 16+ messages in thread
From: Alexandre Belloni @ 2015-01-16 16:57 UTC (permalink / raw)
To: linux-arm-kernel
This is a quite naive implementation to track whether a clocksource is enabled.
I chose not to add a member in struct clocksource and use a flag instead.
I found that timekeeping.c is the only consumer for clocksource and I converted
it to use clocksource_enable and clocksource_disable.
Changes in v2:
- removed the check on enable in timekeeping.c to ensure all clocksources are
going through clocksource_enable
- rework clocksource_enable to set CLOCK_SOURCE_USED when enable is successful
if present
Alexandre Belloni (2):
clocksource: track usage
clocksource: don't suspend/resume when unused
include/linux/clocksource.h | 4 ++++
kernel/time/clocksource.c | 34 ++++++++++++++++++++++++++++++++--
kernel/time/timekeeping.c | 8 +++-----
3 files changed, 39 insertions(+), 7 deletions(-)
--
2.1.0
^ permalink raw reply [flat|nested] 16+ messages in thread
* [PATCH v2 1/2] clocksource: track usage
2015-01-16 16:57 ` Alexandre Belloni
@ 2015-01-16 16:57 ` Alexandre Belloni
-1 siblings, 0 replies; 16+ messages in thread
From: Alexandre Belloni @ 2015-01-16 16:57 UTC (permalink / raw)
To: Thomas Gleixner
Cc: John Stultz, Daniel Lezcano, Nicolas Ferre, Boris Brezillon,
Russell King - ARM Linux, linux-arm-kernel, linux-kernel,
Alexandre Belloni
Track whether the clocksource is enabled or disabled.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
include/linux/clocksource.h | 4 ++++
kernel/time/clocksource.c | 30 ++++++++++++++++++++++++++++++
kernel/time/timekeeping.c | 8 +++-----
3 files changed, 37 insertions(+), 5 deletions(-)
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index abcafaa20b86..7735902fc5f6 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -210,6 +210,8 @@ struct clocksource {
#define CLOCK_SOURCE_SUSPEND_NONSTOP 0x80
#define CLOCK_SOURCE_RESELECT 0x100
+#define CLOCK_SOURCE_USED 0x200
+
/* simplify initialization of mask field */
#define CLOCKSOURCE_MASK(bits) (cycle_t)((bits) < 64 ? ((1ULL<<(bits))-1) : -1)
@@ -282,6 +284,8 @@ static inline s64 clocksource_cyc2ns(cycle_t cycles, u32 mult, u32 shift)
extern int clocksource_register(struct clocksource*);
extern int clocksource_unregister(struct clocksource*);
+extern int clocksource_enable(struct clocksource *);
+extern void clocksource_disable(struct clocksource *);
extern void clocksource_touch_watchdog(void);
extern struct clocksource* clocksource_get_next(void);
extern void clocksource_change_rating(struct clocksource *cs, int rating);
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index b79f39bda7e1..03cfc5a08e3b 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -889,6 +889,36 @@ int clocksource_unregister(struct clocksource *cs)
}
EXPORT_SYMBOL(clocksource_unregister);
+/**
+ * clocksource_enable - enable a registered clocksource
+ * @cs: clocksource to enable
+ */
+int clocksource_enable(struct clocksource *cs)
+{
+ int ret = 0;
+
+ if (cs->enable)
+ ret = cs->enable(cs);
+
+ if (!ret)
+ cs->flags |= CLOCK_SOURCE_USED;
+
+ return ret;
+}
+EXPORT_SYMBOL(clocksource_enable);
+
+/**
+ * clocksource_disable - disable a registered clocksource
+ * @cs: clocksource to disable
+ */
+void clocksource_disable(struct clocksource *cs)
+{
+ cs->flags &= ~CLOCK_SOURCE_USED;
+ if (cs->disable)
+ cs->disable(cs);
+}
+EXPORT_SYMBOL(clocksource_disable);
+
#ifdef CONFIG_SYSFS
/**
* sysfs_show_current_clocksources - sysfs interface for current clocksource
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 6a931852082f..82da6b94382c 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -915,11 +915,10 @@ static int change_clocksource(void *data)
* for built-in code (owner == NULL) as well.
*/
if (try_module_get(new->owner)) {
- if (!new->enable || new->enable(new) == 0) {
+ if (clocksource_enable(new) == 0) {
old = tk->tkr.clock;
tk_setup_internals(tk, new);
- if (old->disable)
- old->disable(old);
+ clocksource_disable(old);
module_put(old->owner);
} else {
module_put(new->owner);
@@ -1080,8 +1079,7 @@ void __init timekeeping_init(void)
ntp_init();
clock = clocksource_default_clock();
- if (clock->enable)
- clock->enable(clock);
+ clocksource_enable(clock);
tk_setup_internals(tk, clock);
tk_set_xtime(tk, &now);
--
2.1.0
^ permalink raw reply related [flat|nested] 16+ messages in thread
* [PATCH v2 1/2] clocksource: track usage
@ 2015-01-16 16:57 ` Alexandre Belloni
0 siblings, 0 replies; 16+ messages in thread
From: Alexandre Belloni @ 2015-01-16 16:57 UTC (permalink / raw)
To: linux-arm-kernel
Track whether the clocksource is enabled or disabled.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
include/linux/clocksource.h | 4 ++++
kernel/time/clocksource.c | 30 ++++++++++++++++++++++++++++++
kernel/time/timekeeping.c | 8 +++-----
3 files changed, 37 insertions(+), 5 deletions(-)
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index abcafaa20b86..7735902fc5f6 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -210,6 +210,8 @@ struct clocksource {
#define CLOCK_SOURCE_SUSPEND_NONSTOP 0x80
#define CLOCK_SOURCE_RESELECT 0x100
+#define CLOCK_SOURCE_USED 0x200
+
/* simplify initialization of mask field */
#define CLOCKSOURCE_MASK(bits) (cycle_t)((bits) < 64 ? ((1ULL<<(bits))-1) : -1)
@@ -282,6 +284,8 @@ static inline s64 clocksource_cyc2ns(cycle_t cycles, u32 mult, u32 shift)
extern int clocksource_register(struct clocksource*);
extern int clocksource_unregister(struct clocksource*);
+extern int clocksource_enable(struct clocksource *);
+extern void clocksource_disable(struct clocksource *);
extern void clocksource_touch_watchdog(void);
extern struct clocksource* clocksource_get_next(void);
extern void clocksource_change_rating(struct clocksource *cs, int rating);
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index b79f39bda7e1..03cfc5a08e3b 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -889,6 +889,36 @@ int clocksource_unregister(struct clocksource *cs)
}
EXPORT_SYMBOL(clocksource_unregister);
+/**
+ * clocksource_enable - enable a registered clocksource
+ * @cs: clocksource to enable
+ */
+int clocksource_enable(struct clocksource *cs)
+{
+ int ret = 0;
+
+ if (cs->enable)
+ ret = cs->enable(cs);
+
+ if (!ret)
+ cs->flags |= CLOCK_SOURCE_USED;
+
+ return ret;
+}
+EXPORT_SYMBOL(clocksource_enable);
+
+/**
+ * clocksource_disable - disable a registered clocksource
+ * @cs: clocksource to disable
+ */
+void clocksource_disable(struct clocksource *cs)
+{
+ cs->flags &= ~CLOCK_SOURCE_USED;
+ if (cs->disable)
+ cs->disable(cs);
+}
+EXPORT_SYMBOL(clocksource_disable);
+
#ifdef CONFIG_SYSFS
/**
* sysfs_show_current_clocksources - sysfs interface for current clocksource
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 6a931852082f..82da6b94382c 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -915,11 +915,10 @@ static int change_clocksource(void *data)
* for built-in code (owner == NULL) as well.
*/
if (try_module_get(new->owner)) {
- if (!new->enable || new->enable(new) == 0) {
+ if (clocksource_enable(new) == 0) {
old = tk->tkr.clock;
tk_setup_internals(tk, new);
- if (old->disable)
- old->disable(old);
+ clocksource_disable(old);
module_put(old->owner);
} else {
module_put(new->owner);
@@ -1080,8 +1079,7 @@ void __init timekeeping_init(void)
ntp_init();
clock = clocksource_default_clock();
- if (clock->enable)
- clock->enable(clock);
+ clocksource_enable(clock);
tk_setup_internals(tk, clock);
tk_set_xtime(tk, &now);
--
2.1.0
^ permalink raw reply related [flat|nested] 16+ messages in thread
* [PATCH v2 2/2] clocksource: don't suspend/resume when unused
2015-01-16 16:57 ` Alexandre Belloni
@ 2015-01-16 16:57 ` Alexandre Belloni
-1 siblings, 0 replies; 16+ messages in thread
From: Alexandre Belloni @ 2015-01-16 16:57 UTC (permalink / raw)
To: Thomas Gleixner
Cc: John Stultz, Daniel Lezcano, Nicolas Ferre, Boris Brezillon,
Russell King - ARM Linux, linux-arm-kernel, linux-kernel,
Alexandre Belloni
There is no point in calling suspend/resume for unused
clocksources.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
kernel/time/clocksource.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 03cfc5a08e3b..da65b3b73a86 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -493,7 +493,7 @@ void clocksource_suspend(void)
struct clocksource *cs;
list_for_each_entry_reverse(cs, &clocksource_list, list)
- if (cs->suspend)
+ if (cs->suspend && (cs->flags & CLOCK_SOURCE_USED))
cs->suspend(cs);
}
@@ -505,7 +505,7 @@ void clocksource_resume(void)
struct clocksource *cs;
list_for_each_entry(cs, &clocksource_list, list)
- if (cs->resume)
+ if (cs->resume && (cs->flags & CLOCK_SOURCE_USED))
cs->resume(cs);
clocksource_resume_watchdog();
--
2.1.0
^ permalink raw reply related [flat|nested] 16+ messages in thread
* [PATCH v2 2/2] clocksource: don't suspend/resume when unused
@ 2015-01-16 16:57 ` Alexandre Belloni
0 siblings, 0 replies; 16+ messages in thread
From: Alexandre Belloni @ 2015-01-16 16:57 UTC (permalink / raw)
To: linux-arm-kernel
There is no point in calling suspend/resume for unused
clocksources.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
kernel/time/clocksource.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 03cfc5a08e3b..da65b3b73a86 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -493,7 +493,7 @@ void clocksource_suspend(void)
struct clocksource *cs;
list_for_each_entry_reverse(cs, &clocksource_list, list)
- if (cs->suspend)
+ if (cs->suspend && (cs->flags & CLOCK_SOURCE_USED))
cs->suspend(cs);
}
@@ -505,7 +505,7 @@ void clocksource_resume(void)
struct clocksource *cs;
list_for_each_entry(cs, &clocksource_list, list)
- if (cs->resume)
+ if (cs->resume && (cs->flags & CLOCK_SOURCE_USED))
cs->resume(cs);
clocksource_resume_watchdog();
--
2.1.0
^ permalink raw reply related [flat|nested] 16+ messages in thread
* Re: [PATCH v2 0/2] clocksource: don't suspend/resume when unused
2015-01-16 16:57 ` Alexandre Belloni
@ 2015-01-16 17:45 ` Boris Brezillon
-1 siblings, 0 replies; 16+ messages in thread
From: Boris Brezillon @ 2015-01-16 17:45 UTC (permalink / raw)
To: Alexandre Belloni
Cc: Thomas Gleixner, John Stultz, Daniel Lezcano, Nicolas Ferre,
Russell King - ARM Linux, linux-arm-kernel, linux-kernel
On Fri, 16 Jan 2015 17:57:17 +0100
Alexandre Belloni <alexandre.belloni@free-electrons.com> wrote:
> This is a quite naive implementation to track whether a clocksource is enabled.
> I chose not to add a member in struct clocksource and use a flag instead.
>
> I found that timekeeping.c is the only consumer for clocksource and I converted
> it to use clocksource_enable and clocksource_disable.
To the whole series:
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
>
> Changes in v2:
> - removed the check on enable in timekeeping.c to ensure all clocksources are
> going through clocksource_enable
> - rework clocksource_enable to set CLOCK_SOURCE_USED when enable is successful
> if present
>
> Alexandre Belloni (2):
> clocksource: track usage
> clocksource: don't suspend/resume when unused
>
> include/linux/clocksource.h | 4 ++++
> kernel/time/clocksource.c | 34 ++++++++++++++++++++++++++++++++--
> kernel/time/timekeeping.c | 8 +++-----
> 3 files changed, 39 insertions(+), 7 deletions(-)
>
--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
^ permalink raw reply [flat|nested] 16+ messages in thread
* [PATCH v2 0/2] clocksource: don't suspend/resume when unused
@ 2015-01-16 17:45 ` Boris Brezillon
0 siblings, 0 replies; 16+ messages in thread
From: Boris Brezillon @ 2015-01-16 17:45 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, 16 Jan 2015 17:57:17 +0100
Alexandre Belloni <alexandre.belloni@free-electrons.com> wrote:
> This is a quite naive implementation to track whether a clocksource is enabled.
> I chose not to add a member in struct clocksource and use a flag instead.
>
> I found that timekeeping.c is the only consumer for clocksource and I converted
> it to use clocksource_enable and clocksource_disable.
To the whole series:
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
>
> Changes in v2:
> - removed the check on enable in timekeeping.c to ensure all clocksources are
> going through clocksource_enable
> - rework clocksource_enable to set CLOCK_SOURCE_USED when enable is successful
> if present
>
> Alexandre Belloni (2):
> clocksource: track usage
> clocksource: don't suspend/resume when unused
>
> include/linux/clocksource.h | 4 ++++
> kernel/time/clocksource.c | 34 ++++++++++++++++++++++++++++++++--
> kernel/time/timekeeping.c | 8 +++-----
> 3 files changed, 39 insertions(+), 7 deletions(-)
>
--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH v2 1/2] clocksource: track usage
2015-01-16 16:57 ` Alexandre Belloni
@ 2015-01-16 19:05 ` John Stultz
-1 siblings, 0 replies; 16+ messages in thread
From: John Stultz @ 2015-01-16 19:05 UTC (permalink / raw)
To: Alexandre Belloni
Cc: Thomas Gleixner, Daniel Lezcano, Nicolas Ferre, Boris Brezillon,
Russell King - ARM Linux, linux-arm-kernel, lkml
On Fri, Jan 16, 2015 at 8:57 AM, Alexandre Belloni
<alexandre.belloni@free-electrons.com> wrote:
> Track whether the clocksource is enabled or disabled.
So.. this commit message needs work. Why do we care to track the
clocksource enabled/disabled state?
thanks
-john
^ permalink raw reply [flat|nested] 16+ messages in thread
* [PATCH v2 1/2] clocksource: track usage
@ 2015-01-16 19:05 ` John Stultz
0 siblings, 0 replies; 16+ messages in thread
From: John Stultz @ 2015-01-16 19:05 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, Jan 16, 2015 at 8:57 AM, Alexandre Belloni
<alexandre.belloni@free-electrons.com> wrote:
> Track whether the clocksource is enabled or disabled.
So.. this commit message needs work. Why do we care to track the
clocksource enabled/disabled state?
thanks
-john
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH v2 1/2] clocksource: track usage
2015-01-16 19:05 ` John Stultz
@ 2015-01-17 1:26 ` Alexandre Belloni
-1 siblings, 0 replies; 16+ messages in thread
From: Alexandre Belloni @ 2015-01-17 1:26 UTC (permalink / raw)
To: John Stultz
Cc: Thomas Gleixner, Daniel Lezcano, Nicolas Ferre, Boris Brezillon,
Russell King - ARM Linux, linux-arm-kernel, lkml
Hi,
On 16/01/2015 at 11:05:46 -0800, John Stultz wrote :
> On Fri, Jan 16, 2015 at 8:57 AM, Alexandre Belloni
> <alexandre.belloni@free-electrons.com> wrote:
> > Track whether the clocksource is enabled or disabled.
>
>
> So.. this commit message needs work. Why do we care to track the
> clocksource enabled/disabled state?
>
What about:
Track whether the clocksource is enabled or disabled. This will allow to
select whether an action is necessary, for example suspend or resume.
--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
^ permalink raw reply [flat|nested] 16+ messages in thread
* [PATCH v2 1/2] clocksource: track usage
@ 2015-01-17 1:26 ` Alexandre Belloni
0 siblings, 0 replies; 16+ messages in thread
From: Alexandre Belloni @ 2015-01-17 1:26 UTC (permalink / raw)
To: linux-arm-kernel
Hi,
On 16/01/2015 at 11:05:46 -0800, John Stultz wrote :
> On Fri, Jan 16, 2015 at 8:57 AM, Alexandre Belloni
> <alexandre.belloni@free-electrons.com> wrote:
> > Track whether the clocksource is enabled or disabled.
>
>
> So.. this commit message needs work. Why do we care to track the
> clocksource enabled/disabled state?
>
What about:
Track whether the clocksource is enabled or disabled. This will allow to
select whether an action is necessary, for example suspend or resume.
--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH v2 1/2] clocksource: track usage
2015-01-16 16:57 ` Alexandre Belloni
@ 2015-01-20 10:51 ` Thomas Gleixner
-1 siblings, 0 replies; 16+ messages in thread
From: Thomas Gleixner @ 2015-01-20 10:51 UTC (permalink / raw)
To: Alexandre Belloni
Cc: John Stultz, Daniel Lezcano, Nicolas Ferre, Boris Brezillon,
Russell King - ARM Linux, linux-arm-kernel, linux-kernel
On Fri, 16 Jan 2015, Alexandre Belloni wrote:
> diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
> index abcafaa20b86..7735902fc5f6 100644
> --- a/include/linux/clocksource.h
> +++ b/include/linux/clocksource.h
> @@ -210,6 +210,8 @@ struct clocksource {
> #define CLOCK_SOURCE_SUSPEND_NONSTOP 0x80
> #define CLOCK_SOURCE_RESELECT 0x100
>
> +#define CLOCK_SOURCE_USED 0x200
You track whether the clocksource is enabled or not, right?
> /* simplify initialization of mask field */
> #define CLOCKSOURCE_MASK(bits) (cycle_t)((bits) < 64 ? ((1ULL<<(bits))-1) : -1)
>
> @@ -282,6 +284,8 @@ static inline s64 clocksource_cyc2ns(cycle_t cycles, u32 mult, u32 shift)
>
> extern int clocksource_register(struct clocksource*);
> extern int clocksource_unregister(struct clocksource*);
> +extern int clocksource_enable(struct clocksource *);
> +extern void clocksource_disable(struct clocksource *);
This should be in kernel/time/timekeeping_internal.h
> extern void clocksource_touch_watchdog(void);
> extern struct clocksource* clocksource_get_next(void);
> extern void clocksource_change_rating(struct clocksource *cs, int rating);
> diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
> index b79f39bda7e1..03cfc5a08e3b 100644
> --- a/kernel/time/clocksource.c
> +++ b/kernel/time/clocksource.c
> @@ -889,6 +889,36 @@ int clocksource_unregister(struct clocksource *cs)
> }
> EXPORT_SYMBOL(clocksource_unregister);
>
> +/**
> + * clocksource_enable - enable a registered clocksource
> + * @cs: clocksource to enable
> + */
> +int clocksource_enable(struct clocksource *cs)
> +{
> + int ret = 0;
> +
> + if (cs->enable)
> + ret = cs->enable(cs);
> +
> + if (!ret)
> + cs->flags |= CLOCK_SOURCE_USED;
> +
> + return ret;
> +}
> +EXPORT_SYMBOL(clocksource_enable);
Why on earth do you want to export that?
> +/**
> + * clocksource_disable - disable a registered clocksource
> + * @cs: clocksource to disable
> + */
> +void clocksource_disable(struct clocksource *cs)
> +{
> + cs->flags &= ~CLOCK_SOURCE_USED;
> + if (cs->disable)
> + cs->disable(cs);
> +}
> +EXPORT_SYMBOL(clocksource_disable);
Ditto.
Thanks,
tglx
^ permalink raw reply [flat|nested] 16+ messages in thread
* [PATCH v2 1/2] clocksource: track usage
@ 2015-01-20 10:51 ` Thomas Gleixner
0 siblings, 0 replies; 16+ messages in thread
From: Thomas Gleixner @ 2015-01-20 10:51 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, 16 Jan 2015, Alexandre Belloni wrote:
> diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
> index abcafaa20b86..7735902fc5f6 100644
> --- a/include/linux/clocksource.h
> +++ b/include/linux/clocksource.h
> @@ -210,6 +210,8 @@ struct clocksource {
> #define CLOCK_SOURCE_SUSPEND_NONSTOP 0x80
> #define CLOCK_SOURCE_RESELECT 0x100
>
> +#define CLOCK_SOURCE_USED 0x200
You track whether the clocksource is enabled or not, right?
> /* simplify initialization of mask field */
> #define CLOCKSOURCE_MASK(bits) (cycle_t)((bits) < 64 ? ((1ULL<<(bits))-1) : -1)
>
> @@ -282,6 +284,8 @@ static inline s64 clocksource_cyc2ns(cycle_t cycles, u32 mult, u32 shift)
>
> extern int clocksource_register(struct clocksource*);
> extern int clocksource_unregister(struct clocksource*);
> +extern int clocksource_enable(struct clocksource *);
> +extern void clocksource_disable(struct clocksource *);
This should be in kernel/time/timekeeping_internal.h
> extern void clocksource_touch_watchdog(void);
> extern struct clocksource* clocksource_get_next(void);
> extern void clocksource_change_rating(struct clocksource *cs, int rating);
> diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
> index b79f39bda7e1..03cfc5a08e3b 100644
> --- a/kernel/time/clocksource.c
> +++ b/kernel/time/clocksource.c
> @@ -889,6 +889,36 @@ int clocksource_unregister(struct clocksource *cs)
> }
> EXPORT_SYMBOL(clocksource_unregister);
>
> +/**
> + * clocksource_enable - enable a registered clocksource
> + * @cs: clocksource to enable
> + */
> +int clocksource_enable(struct clocksource *cs)
> +{
> + int ret = 0;
> +
> + if (cs->enable)
> + ret = cs->enable(cs);
> +
> + if (!ret)
> + cs->flags |= CLOCK_SOURCE_USED;
> +
> + return ret;
> +}
> +EXPORT_SYMBOL(clocksource_enable);
Why on earth do you want to export that?
> +/**
> + * clocksource_disable - disable a registered clocksource
> + * @cs: clocksource to disable
> + */
> +void clocksource_disable(struct clocksource *cs)
> +{
> + cs->flags &= ~CLOCK_SOURCE_USED;
> + if (cs->disable)
> + cs->disable(cs);
> +}
> +EXPORT_SYMBOL(clocksource_disable);
Ditto.
Thanks,
tglx
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH v2 2/2] clocksource: don't suspend/resume when unused
2015-01-16 16:57 ` Alexandre Belloni
@ 2015-01-20 11:13 ` Thomas Gleixner
-1 siblings, 0 replies; 16+ messages in thread
From: Thomas Gleixner @ 2015-01-20 11:13 UTC (permalink / raw)
To: Alexandre Belloni
Cc: John Stultz, Daniel Lezcano, Nicolas Ferre, Boris Brezillon,
Russell King - ARM Linux, linux-arm-kernel, linux-kernel
On Fri, 16 Jan 2015, Alexandre Belloni wrote:
> There is no point in calling suspend/resume for unused
> clocksources.
That's true, but ....
> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> ---
> kernel/time/clocksource.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
> index 03cfc5a08e3b..da65b3b73a86 100644
> --- a/kernel/time/clocksource.c
> +++ b/kernel/time/clocksource.c
> @@ -493,7 +493,7 @@ void clocksource_suspend(void)
> struct clocksource *cs;
>
> list_for_each_entry_reverse(cs, &clocksource_list, list)
> - if (cs->suspend)
> + if (cs->suspend && (cs->flags & CLOCK_SOURCE_USED))
> cs->suspend(cs);
> }
>
> @@ -505,7 +505,7 @@ void clocksource_resume(void)
> struct clocksource *cs;
>
> list_for_each_entry(cs, &clocksource_list, list)
> - if (cs->resume)
> + if (cs->resume && (cs->flags & CLOCK_SOURCE_USED))
> cs->resume(cs);
I had a deeper look at the clocksources which have a resume
callback. We have implementations, which rely on the resume callback
being called unconditionally. e.g.: arch/x86/kernel/hpet.c. And there
are a few others which have extra PM code in the suspend/resume path
independent of the fact whether the clocksource is enabled or not.
So we really need to make this opt-in with a per clocksource flag.
Thanks,
tglx
^ permalink raw reply [flat|nested] 16+ messages in thread
* [PATCH v2 2/2] clocksource: don't suspend/resume when unused
@ 2015-01-20 11:13 ` Thomas Gleixner
0 siblings, 0 replies; 16+ messages in thread
From: Thomas Gleixner @ 2015-01-20 11:13 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, 16 Jan 2015, Alexandre Belloni wrote:
> There is no point in calling suspend/resume for unused
> clocksources.
That's true, but ....
> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> ---
> kernel/time/clocksource.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
> index 03cfc5a08e3b..da65b3b73a86 100644
> --- a/kernel/time/clocksource.c
> +++ b/kernel/time/clocksource.c
> @@ -493,7 +493,7 @@ void clocksource_suspend(void)
> struct clocksource *cs;
>
> list_for_each_entry_reverse(cs, &clocksource_list, list)
> - if (cs->suspend)
> + if (cs->suspend && (cs->flags & CLOCK_SOURCE_USED))
> cs->suspend(cs);
> }
>
> @@ -505,7 +505,7 @@ void clocksource_resume(void)
> struct clocksource *cs;
>
> list_for_each_entry(cs, &clocksource_list, list)
> - if (cs->resume)
> + if (cs->resume && (cs->flags & CLOCK_SOURCE_USED))
> cs->resume(cs);
I had a deeper look at the clocksources which have a resume
callback. We have implementations, which rely on the resume callback
being called unconditionally. e.g.: arch/x86/kernel/hpet.c. And there
are a few others which have extra PM code in the suspend/resume path
independent of the fact whether the clocksource is enabled or not.
So we really need to make this opt-in with a per clocksource flag.
Thanks,
tglx
^ permalink raw reply [flat|nested] 16+ messages in thread
end of thread, other threads:[~2015-01-20 11:13 UTC | newest]
Thread overview: 16+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-01-16 16:57 [PATCH v2 0/2] clocksource: don't suspend/resume when unused Alexandre Belloni
2015-01-16 16:57 ` Alexandre Belloni
2015-01-16 16:57 ` [PATCH v2 1/2] clocksource: track usage Alexandre Belloni
2015-01-16 16:57 ` Alexandre Belloni
2015-01-16 19:05 ` John Stultz
2015-01-16 19:05 ` John Stultz
2015-01-17 1:26 ` Alexandre Belloni
2015-01-17 1:26 ` Alexandre Belloni
2015-01-20 10:51 ` Thomas Gleixner
2015-01-20 10:51 ` Thomas Gleixner
2015-01-16 16:57 ` [PATCH v2 2/2] clocksource: don't suspend/resume when unused Alexandre Belloni
2015-01-16 16:57 ` Alexandre Belloni
2015-01-20 11:13 ` Thomas Gleixner
2015-01-20 11:13 ` Thomas Gleixner
2015-01-16 17:45 ` [PATCH v2 0/2] " Boris Brezillon
2015-01-16 17:45 ` Boris Brezillon
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