* [PATCH v4 0/2] make arm_cpuidle_suspend() a bit more efficient
@ 2016-07-06 6:15 Jisheng Zhang
2016-07-06 6:15 ` [PATCH v4 1/2] ARM: cpuidle: fix !cpuidle_ops[cpu].init case during init Jisheng Zhang
2016-07-06 6:15 ` [PATCH v4 2/2] ARM: cpuidle: make arm_cpuidle_suspend() a bit more efficient Jisheng Zhang
0 siblings, 2 replies; 10+ messages in thread
From: Jisheng Zhang @ 2016-07-06 6:15 UTC (permalink / raw)
To: daniel.lezcano, lorenzo.pieralisi, lina.iyer, linux
Cc: linux-arm-kernel, linux-kernel, Jisheng Zhang
There's one corner case need to be fixed: !cpuidle_ops[cpu].init.
patch1 tries to address this corner case.
patch2 tries to improve arm_cpuidle_suspend() a bit by moving .suspend
check into arm_cpuidle_read_ops().
Since v3:
- rebased on 4.7-rc1
Since v2:
- add back patch1.
Since v1:
- drop patch1, I.E "ARM: cpuidle: fix !cpuidle_ops[cpu].init case
during init", because there may be platforms which doesn't need the
init member at all.
- adopt Daniel's suggestion to move the cpuidle_ops.suspend check to
arm_cpuidle_read_ops().
Jisheng Zhang (2):
ARM: cpuidle: fix !cpuidle_ops[cpu].init case during init
ARM: cpuidle: make arm_cpuidle_suspend() a bit more efficient
arch/arm/kernel/cpuidle.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
--
2.8.1
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v4 1/2] ARM: cpuidle: fix !cpuidle_ops[cpu].init case during init
2016-07-06 6:15 [PATCH v4 0/2] make arm_cpuidle_suspend() a bit more efficient Jisheng Zhang
@ 2016-07-06 6:15 ` Jisheng Zhang
2016-07-07 13:45 ` Daniel Lezcano
2016-07-06 6:15 ` [PATCH v4 2/2] ARM: cpuidle: make arm_cpuidle_suspend() a bit more efficient Jisheng Zhang
1 sibling, 1 reply; 10+ messages in thread
From: Jisheng Zhang @ 2016-07-06 6:15 UTC (permalink / raw)
To: daniel.lezcano, lorenzo.pieralisi, lina.iyer, linux
Cc: linux-arm-kernel, linux-kernel, Jisheng Zhang
Let's assume cpuidle_ops exists but it doesn't implement the according
init callback, current arm_cpuidle_init() will return success to its
caller, but in fact it should return -EOPNOTSUPP.
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
---
arch/arm/kernel/cpuidle.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/arch/arm/kernel/cpuidle.c b/arch/arm/kernel/cpuidle.c
index a44b268e..2129b29 100644
--- a/arch/arm/kernel/cpuidle.c
+++ b/arch/arm/kernel/cpuidle.c
@@ -92,7 +92,8 @@ static const struct cpuidle_ops *__init arm_cpuidle_get_ops(const char *method)
* process.
*
* Return 0 on sucess, -ENOENT if no 'enable-method' is defined, -EOPNOTSUPP if
- * no cpuidle_ops is registered for the 'enable-method'.
+ * no cpuidle_ops is registered for the 'enable-method', or if no init callback
+ * is defined.
*/
static int __init arm_cpuidle_read_ops(struct device_node *dn, int cpu)
{
@@ -110,6 +111,12 @@ static int __init arm_cpuidle_read_ops(struct device_node *dn, int cpu)
return -EOPNOTSUPP;
}
+ if (!ops->init) {
+ pr_warn("cpuidle_ops '%s': no init callback\n",
+ enable_method);
+ return -EOPNOTSUPP;
+ }
+
cpuidle_ops[cpu] = *ops; /* structure copy */
pr_notice("cpuidle: enable-method property '%s'"
@@ -129,7 +136,8 @@ static int __init arm_cpuidle_read_ops(struct device_node *dn, int cpu)
* Returns:
* 0 on success,
* -ENODEV if it fails to find the cpu node in the device tree,
- * -EOPNOTSUPP if it does not find a registered cpuidle_ops for this cpu,
+ * -EOPNOTSUPP if it does not find a registered and valid cpuidle_ops for
+ * this cpu,
* -ENOENT if it fails to find an 'enable-method' property,
* -ENXIO if the HW reports a failure or a misconfiguration,
* -ENOMEM if the HW report an memory allocation failure
@@ -143,7 +151,7 @@ int __init arm_cpuidle_init(int cpu)
return -ENODEV;
ret = arm_cpuidle_read_ops(cpu_node, cpu);
- if (!ret && cpuidle_ops[cpu].init)
+ if (!ret)
ret = cpuidle_ops[cpu].init(cpu_node, cpu);
of_node_put(cpu_node);
--
2.8.1
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v4 2/2] ARM: cpuidle: make arm_cpuidle_suspend() a bit more efficient
2016-07-06 6:15 [PATCH v4 0/2] make arm_cpuidle_suspend() a bit more efficient Jisheng Zhang
2016-07-06 6:15 ` [PATCH v4 1/2] ARM: cpuidle: fix !cpuidle_ops[cpu].init case during init Jisheng Zhang
@ 2016-07-06 6:15 ` Jisheng Zhang
2016-07-07 13:46 ` Daniel Lezcano
1 sibling, 1 reply; 10+ messages in thread
From: Jisheng Zhang @ 2016-07-06 6:15 UTC (permalink / raw)
To: daniel.lezcano, lorenzo.pieralisi, lina.iyer, linux
Cc: linux-arm-kernel, linux-kernel, Jisheng Zhang
Currently, we check cpuidle_ops.suspend every time when entering a
low-power idle state. But this check could be avoided in this hot path
by moving it into arm_cpuidle_read_ops() to reduce arm_cpuidle_suspend
overhead a bit.
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
---
arch/arm/kernel/cpuidle.c | 17 ++++++-----------
1 file changed, 6 insertions(+), 11 deletions(-)
diff --git a/arch/arm/kernel/cpuidle.c b/arch/arm/kernel/cpuidle.c
index 2129b29..7dccc96 100644
--- a/arch/arm/kernel/cpuidle.c
+++ b/arch/arm/kernel/cpuidle.c
@@ -47,18 +47,13 @@ int arm_cpuidle_simple_enter(struct cpuidle_device *dev,
* This function calls the underlying arch specific low level PM code as
* registered at the init time.
*
- * Returns -EOPNOTSUPP if no suspend callback is defined, the result of the
- * callback otherwise.
+ * Returns the result of the suspend callback.
*/
int arm_cpuidle_suspend(int index)
{
- int ret = -EOPNOTSUPP;
int cpu = smp_processor_id();
- if (cpuidle_ops[cpu].suspend)
- ret = cpuidle_ops[cpu].suspend(index);
-
- return ret;
+ return cpuidle_ops[cpu].suspend(index);
}
/**
@@ -92,8 +87,8 @@ static const struct cpuidle_ops *__init arm_cpuidle_get_ops(const char *method)
* process.
*
* Return 0 on sucess, -ENOENT if no 'enable-method' is defined, -EOPNOTSUPP if
- * no cpuidle_ops is registered for the 'enable-method', or if no init callback
- * is defined.
+ * no cpuidle_ops is registered for the 'enable-method', or if either init or
+ * suspend callback isn't defined.
*/
static int __init arm_cpuidle_read_ops(struct device_node *dn, int cpu)
{
@@ -111,8 +106,8 @@ static int __init arm_cpuidle_read_ops(struct device_node *dn, int cpu)
return -EOPNOTSUPP;
}
- if (!ops->init) {
- pr_warn("cpuidle_ops '%s': no init callback\n",
+ if (!ops->init || !ops->suspend) {
+ pr_warn("cpuidle_ops '%s': no init or suspend callback\n",
enable_method);
return -EOPNOTSUPP;
}
--
2.8.1
^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH v4 1/2] ARM: cpuidle: fix !cpuidle_ops[cpu].init case during init
2016-07-06 6:15 ` [PATCH v4 1/2] ARM: cpuidle: fix !cpuidle_ops[cpu].init case during init Jisheng Zhang
@ 2016-07-07 13:45 ` Daniel Lezcano
0 siblings, 0 replies; 10+ messages in thread
From: Daniel Lezcano @ 2016-07-07 13:45 UTC (permalink / raw)
To: Jisheng Zhang
Cc: lorenzo.pieralisi, lina.iyer, linux, linux-arm-kernel, linux-kernel
On Wed, Jul 06, 2016 at 02:15:54PM +0800, Jisheng Zhang wrote:
> Let's assume cpuidle_ops exists but it doesn't implement the according
> init callback, current arm_cpuidle_init() will return success to its
> caller, but in fact it should return -EOPNOTSUPP.
>
> Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
> ---
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v4 2/2] ARM: cpuidle: make arm_cpuidle_suspend() a bit more efficient
2016-07-06 6:15 ` [PATCH v4 2/2] ARM: cpuidle: make arm_cpuidle_suspend() a bit more efficient Jisheng Zhang
@ 2016-07-07 13:46 ` Daniel Lezcano
2016-07-08 6:17 ` Jisheng Zhang
0 siblings, 1 reply; 10+ messages in thread
From: Daniel Lezcano @ 2016-07-07 13:46 UTC (permalink / raw)
To: Jisheng Zhang
Cc: lorenzo.pieralisi, lina.iyer, linux, linux-arm-kernel, linux-kernel
On Wed, Jul 06, 2016 at 02:15:55PM +0800, Jisheng Zhang wrote:
> Currently, we check cpuidle_ops.suspend every time when entering a
> low-power idle state. But this check could be avoided in this hot path
> by moving it into arm_cpuidle_read_ops() to reduce arm_cpuidle_suspend
> overhead a bit.
>
> Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
> ---
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v4 2/2] ARM: cpuidle: make arm_cpuidle_suspend() a bit more efficient
2016-07-07 13:46 ` Daniel Lezcano
@ 2016-07-08 6:17 ` Jisheng Zhang
2016-07-08 10:50 ` Daniel Lezcano
0 siblings, 1 reply; 10+ messages in thread
From: Jisheng Zhang @ 2016-07-08 6:17 UTC (permalink / raw)
To: Daniel Lezcano
Cc: lorenzo.pieralisi, lina.iyer, linux, linux-arm-kernel, linux-kernel
Dear Daniel,
On Thu, 7 Jul 2016 15:46:28 +0200 Daniel Lezcano wrote:
> On Wed, Jul 06, 2016 at 02:15:55PM +0800, Jisheng Zhang wrote:
> > Currently, we check cpuidle_ops.suspend every time when entering a
> > low-power idle state. But this check could be avoided in this hot path
> > by moving it into arm_cpuidle_read_ops() to reduce arm_cpuidle_suspend
> > overhead a bit.
> >
> > Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
> > ---
>
> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
I'm not sure the upstream merging path this patch should follow, Per my
understanding, I need to put it into Russell's PATCH system.
Thanks in advance,
Jisheng
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v4 2/2] ARM: cpuidle: make arm_cpuidle_suspend() a bit more efficient
2016-07-08 6:17 ` Jisheng Zhang
@ 2016-07-08 10:50 ` Daniel Lezcano
2016-07-08 10:58 ` Jisheng Zhang
0 siblings, 1 reply; 10+ messages in thread
From: Daniel Lezcano @ 2016-07-08 10:50 UTC (permalink / raw)
To: Jisheng Zhang
Cc: lorenzo.pieralisi, lina.iyer, linux, linux-arm-kernel, linux-kernel
On Fri, Jul 08, 2016 at 02:17:29PM +0800, Jisheng Zhang wrote:
> Dear Daniel,
>
> On Thu, 7 Jul 2016 15:46:28 +0200 Daniel Lezcano wrote:
>
> > On Wed, Jul 06, 2016 at 02:15:55PM +0800, Jisheng Zhang wrote:
> > > Currently, we check cpuidle_ops.suspend every time when entering a
> > > low-power idle state. But this check could be avoided in this hot path
> > > by moving it into arm_cpuidle_read_ops() to reduce arm_cpuidle_suspend
> > > overhead a bit.
> > >
> > > Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
> > > ---
> >
> > Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
>
> I'm not sure the upstream merging path this patch should follow, Per my
> understanding, I need to put it into Russell's PATCH system.
Or alternatively through arm-soc
-- Daniel
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v4 2/2] ARM: cpuidle: make arm_cpuidle_suspend() a bit more efficient
2016-07-08 10:50 ` Daniel Lezcano
@ 2016-07-08 10:58 ` Jisheng Zhang
2016-07-14 15:31 ` Russell King - ARM Linux
0 siblings, 1 reply; 10+ messages in thread
From: Jisheng Zhang @ 2016-07-08 10:58 UTC (permalink / raw)
To: Daniel Lezcano, Arnd Bergmann, Olof Johansson
Cc: lorenzo.pieralisi, lina.iyer, linux, linux-arm-kernel, linux-kernel, arm
On Fri, 8 Jul 2016 12:50:12 +0200 Daniel Lezcano wrote:
> On Fri, Jul 08, 2016 at 02:17:29PM +0800, Jisheng Zhang wrote:
> > Dear Daniel,
> >
> > On Thu, 7 Jul 2016 15:46:28 +0200 Daniel Lezcano wrote:
> >
> > > On Wed, Jul 06, 2016 at 02:15:55PM +0800, Jisheng Zhang wrote:
> > > > Currently, we check cpuidle_ops.suspend every time when entering a
> > > > low-power idle state. But this check could be avoided in this hot path
> > > > by moving it into arm_cpuidle_read_ops() to reduce arm_cpuidle_suspend
> > > > overhead a bit.
> > > >
> > > > Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
> > > > ---
> > >
> > > Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> >
> > I'm not sure the upstream merging path this patch should follow, Per my
> > understanding, I need to put it into Russell's PATCH system.
>
> Or alternatively through arm-soc
>
Got it. thanks.
Dear Arnd, Olof,
I have no pull request permission. what's your preference? Could you please
advise?
Thanks
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v4 2/2] ARM: cpuidle: make arm_cpuidle_suspend() a bit more efficient
2016-07-08 10:58 ` Jisheng Zhang
@ 2016-07-14 15:31 ` Russell King - ARM Linux
2016-07-15 7:38 ` Jisheng Zhang
0 siblings, 1 reply; 10+ messages in thread
From: Russell King - ARM Linux @ 2016-07-14 15:31 UTC (permalink / raw)
To: Jisheng Zhang, arm
Cc: Daniel Lezcano, Arnd Bergmann, Olof Johansson, lorenzo.pieralisi,
lina.iyer, linux-arm-kernel, linux-kernel
On Fri, Jul 08, 2016 at 06:58:54PM +0800, Jisheng Zhang wrote:
> On Fri, 8 Jul 2016 12:50:12 +0200 Daniel Lezcano wrote:
>
> > On Fri, Jul 08, 2016 at 02:17:29PM +0800, Jisheng Zhang wrote:
> > > Dear Daniel,
> > >
> > > On Thu, 7 Jul 2016 15:46:28 +0200 Daniel Lezcano wrote:
> > >
> > > > On Wed, Jul 06, 2016 at 02:15:55PM +0800, Jisheng Zhang wrote:
> > > > > Currently, we check cpuidle_ops.suspend every time when entering a
> > > > > low-power idle state. But this check could be avoided in this hot path
> > > > > by moving it into arm_cpuidle_read_ops() to reduce arm_cpuidle_suspend
> > > > > overhead a bit.
> > > > >
> > > > > Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
> > > > > ---
> > > >
> > > > Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> > >
> > > I'm not sure the upstream merging path this patch should follow, Per my
> > > understanding, I need to put it into Russell's PATCH system.
> >
> > Or alternatively through arm-soc
> >
>
> Got it. thanks.
>
> Dear Arnd, Olof,
>
> I have no pull request permission. what's your preference? Could you please
> advise?
... and because arm-soc people haven't responded, they've now ended up
in the patch system... So I've applied them to my tree in a separate
branch.
Thanks!
--
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v4 2/2] ARM: cpuidle: make arm_cpuidle_suspend() a bit more efficient
2016-07-14 15:31 ` Russell King - ARM Linux
@ 2016-07-15 7:38 ` Jisheng Zhang
0 siblings, 0 replies; 10+ messages in thread
From: Jisheng Zhang @ 2016-07-15 7:38 UTC (permalink / raw)
To: Russell King - ARM Linux
Cc: arm, Daniel Lezcano, Arnd Bergmann, Olof Johansson,
lorenzo.pieralisi, lina.iyer, linux-arm-kernel, linux-kernel
On Thu, 14 Jul 2016 16:31:13 +0100 Russell King - ARM Linux wrote:
> On Fri, Jul 08, 2016 at 06:58:54PM +0800, Jisheng Zhang wrote:
> > On Fri, 8 Jul 2016 12:50:12 +0200 Daniel Lezcano wrote:
> >
> > > On Fri, Jul 08, 2016 at 02:17:29PM +0800, Jisheng Zhang wrote:
> > > > Dear Daniel,
> > > >
> > > > On Thu, 7 Jul 2016 15:46:28 +0200 Daniel Lezcano wrote:
> > > >
> > > > > On Wed, Jul 06, 2016 at 02:15:55PM +0800, Jisheng Zhang wrote:
> > > > > > Currently, we check cpuidle_ops.suspend every time when entering a
> > > > > > low-power idle state. But this check could be avoided in this hot path
> > > > > > by moving it into arm_cpuidle_read_ops() to reduce arm_cpuidle_suspend
> > > > > > overhead a bit.
> > > > > >
> > > > > > Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
> > > > > > ---
> > > > >
> > > > > Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> > > >
> > > > I'm not sure the upstream merging path this patch should follow, Per my
> > > > understanding, I need to put it into Russell's PATCH system.
> > >
> > > Or alternatively through arm-soc
> > >
> >
> > Got it. thanks.
> >
> > Dear Arnd, Olof,
> >
> > I have no pull request permission. what's your preference? Could you please
> > advise?
>
> ... and because arm-soc people haven't responded, they've now ended up
> in the patch system... So I've applied them to my tree in a separate
> branch.
>
Thank you so much!
^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2016-07-15 7:43 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
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2016-07-06 6:15 [PATCH v4 0/2] make arm_cpuidle_suspend() a bit more efficient Jisheng Zhang
2016-07-06 6:15 ` [PATCH v4 1/2] ARM: cpuidle: fix !cpuidle_ops[cpu].init case during init Jisheng Zhang
2016-07-07 13:45 ` Daniel Lezcano
2016-07-06 6:15 ` [PATCH v4 2/2] ARM: cpuidle: make arm_cpuidle_suspend() a bit more efficient Jisheng Zhang
2016-07-07 13:46 ` Daniel Lezcano
2016-07-08 6:17 ` Jisheng Zhang
2016-07-08 10:50 ` Daniel Lezcano
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2016-07-14 15:31 ` Russell King - ARM Linux
2016-07-15 7:38 ` Jisheng Zhang
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