Re: [PATCH] cpuidle: move field disable from per-driver to per-cpu

From: Yanmin Zhang
Date: Mon Jun 18 2012 - 02:41:23 EST


On Fri, 2012-06-15 at 17:38 +0530, Deepthi Dharwar wrote:
> On 06/14/2012 08:22 AM, ShuoX Liu wrote:
>
> > From: ShuoX Liu <shuox.liu@xxxxxxxxx>
> >
> > Andrew J.Schorr raises a question. When he changes the disable setting
> > on a single CPU, it affects all the other CPUs. Basically, currently,
> > the disable field is per-driver instead of per-cpu. All the C states of
> > the same driver are shared by all CPU in the same machine.
> >
> > Below patch changes field disable to per-cpu, so we could set this
> > separately for each cpu.
> >
>
>
> This would help us have asymmetric C-states on cpus.
>
> > Reported-by: Andrew J.Schorr <aschorr@xxxxxxxxxxxxxxxxxxxxxxxxx>
> > Reviewed-by: Yanmin Zhang <yanmin_zhang@xxxxxxxxx>
> > Signed-off-by: ShuoX Liu <shuox.liu@xxxxxxxxx>
>
>
> Acked-by: Deepthi Dharwar <deepthi@xxxxxxxxxxxxxxxxxx>
Len,

Would you like to accept the patch into your testing tree?
Both Deepthi Dharwar and Andrew J. Schorr acked the patch is
useful.

>
> > ---
> > drivers/cpuidle/cpuidle.c | 1 -
> > drivers/cpuidle/governors/menu.c | 5 +++--
> > drivers/cpuidle/sysfs.c | 21 ++++++++++++---------
> > include/linux/cpuidle.h | 2 +-
> > 4 files changed, 16 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
> > index d90519c..04e4b76 100644
> > --- a/drivers/cpuidle/cpuidle.c
> > +++ b/drivers/cpuidle/cpuidle.c
> > @@ -265,7 +265,6 @@ static void poll_idle_init(struct cpuidle_driver *drv)
> > state->power_usage = -1;
> > state->flags = 0;
> > state->enter = poll_idle;
> > - state->disable = 0;
> > }
> > #else
> > static void poll_idle_init(struct cpuidle_driver *drv) {}
> > diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
> > index 0633575..8391d93 100644
> > --- a/drivers/cpuidle/governors/menu.c
> > +++ b/drivers/cpuidle/governors/menu.c
> > @@ -281,7 +281,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
> > * unless the timer is happening really really soon.
> > */
> > if (data->expected_us > 5 &&
> > - drv->states[CPUIDLE_DRIVER_STATE_START].disable == 0)
> > + dev->states_usage[CPUIDLE_DRIVER_STATE_START].disable == 0)
> > data->last_state_idx = CPUIDLE_DRIVER_STATE_START;
> >
> > /*
> > @@ -290,8 +290,9 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
> > */
> > for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) {
> > struct cpuidle_state *s = &drv->states[i];
> > + struct cpuidle_state_usage *su = &dev->states_usage[i];
> >
> > - if (s->disable)
> > + if (su->disable)
> > continue;
> > if (s->target_residency > data->predicted_us)
> > continue;
> > diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c
> > index 88032b4..5f809e3 100644
> > --- a/drivers/cpuidle/sysfs.c
> > +++ b/drivers/cpuidle/sysfs.c
> > @@ -217,7 +217,8 @@ struct cpuidle_state_attr {
> > struct attribute attr;
> > ssize_t (*show)(struct cpuidle_state *, \
> > struct cpuidle_state_usage *, char *);
> > - ssize_t (*store)(struct cpuidle_state *, const char *, size_t);
> > + ssize_t (*store)(struct cpuidle_state *, \
> > + struct cpuidle_state_usage *, const char *, size_t);
> > };
> >
> > #define define_one_state_ro(_name, show) \
> > @@ -233,21 +234,22 @@ static ssize_t show_state_##_name(struct cpuidle_state *state, \
> > return sprintf(buf, "%u\n", state->_name);\
> > }
> >
> > -#define define_store_state_function(_name) \
> > +#define define_store_state_ull_function(_name) \
> > static ssize_t store_state_##_name(struct cpuidle_state *state, \
> > + struct cpuidle_state_usage *state_usage, \
> > const char *buf, size_t size) \
> > { \
> > - long value; \
> > + unsigned long long value; \
> > int err; \
> > if (!capable(CAP_SYS_ADMIN)) \
> > return -EPERM; \
> > - err = kstrtol(buf, 0, &value); \
> > + err = kstrtoull(buf, 0, &value); \
> > if (err) \
> > return err; \
> > if (value) \
> > - state->disable = 1; \
> > + state_usage->_name = 1; \
> > else \
> > - state->disable = 0; \
> > + state_usage->_name = 0; \
> > return size; \
> > }
> >
> > @@ -273,8 +275,8 @@ define_show_state_ull_function(usage)
> > define_show_state_ull_function(time)
> > define_show_state_str_function(name)
> > define_show_state_str_function(desc)
> > -define_show_state_function(disable)
> > -define_store_state_function(disable)
> > +define_show_state_ull_function(disable)
> > +define_store_state_ull_function(disable)
> >
> > define_one_state_ro(name, show_state_name);
> > define_one_state_ro(desc, show_state_desc);
> > @@ -318,10 +320,11 @@ static ssize_t cpuidle_state_store(struct kobject *kobj,
> > {
> > int ret = -EIO;
> > struct cpuidle_state *state = kobj_to_state(kobj);
> > + struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
> > struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
> >
> > if (cattr->store)
> > - ret = cattr->store(state, buf, size);
> > + ret = cattr->store(state, state_usage, buf, size);
> >
> > return ret;
> > }
> > diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
> > index 6c26a3d..8570012 100644
> > --- a/include/linux/cpuidle.h
> > +++ b/include/linux/cpuidle.h
> > @@ -34,6 +34,7 @@ struct cpuidle_driver;
> > struct cpuidle_state_usage {
> > void *driver_data;
> >
> > + unsigned long long disable;
> > unsigned long long usage;
> > unsigned long long time; /* in US */
> > };
> > @@ -46,7 +47,6 @@ struct cpuidle_state {
> > unsigned int exit_latency; /* in US */
> > int power_usage; /* in mW */
> > unsigned int target_residency; /* in US */
> > - unsigned int disable;
> >
> > int (*enter) (struct cpuidle_device *dev,
> > struct cpuidle_driver *drv,
>
>
> --
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