Re: [PATCH v2 linux-next] cpufreq: governors: Calculate iowait time only when necessary
On 03/22/2013 01:54 AM, Rafael J. Wysocki wrote: > > Applied to linux-pm.git/bleeding-edge and will be moved to linux-next if there > are no build problems in the bleeding-edge branch. > > Thanks, > Rafael Hi Rafael, I just noticed a regression with this patch with the calculation of wall time in get get_cpu_idle_time that prevents the CPU to increase to max frequency, when we use ondemand with io_is_busy = 1. I'm sorry about that, I'm sending a patch to fix it. Regards, Stratos -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v2 linux-next] cpufreq: governors: Calculate iowait time only when necessary
On 03/22/2013 01:54 AM, Rafael J. Wysocki wrote: Applied to linux-pm.git/bleeding-edge and will be moved to linux-next if there are no build problems in the bleeding-edge branch. Thanks, Rafael Hi Rafael, I just noticed a regression with this patch with the calculation of wall time in get get_cpu_idle_time that prevents the CPU to increase to max frequency, when we use ondemand with io_is_busy = 1. I'm sorry about that, I'm sending a patch to fix it. Regards, Stratos -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v2 linux-next] cpufreq: governors: Calculate iowait time only when necessary
On Friday, March 01, 2013 09:18:08 AM Viresh Kumar wrote:
> On 28 February 2013 22:27, Stratos Karafotis wrote:
> > Currently we always calculate the CPU iowait time and add it to idle time.
> > If we are in ondemand and we use io_is_busy, we re-calculate iowait time
> > and we subtract it from idle time.
> >
> > With this patch iowait time is calculated only when necessary avoiding
> > the double call to get_cpu_iowait_time_us. We use a parameter in
> > function get_cpu_idle_time to distinguish when the iowait time will be
> > added to idle time or not, without the need of keeping the prev_io_wait.
> >
> > Signed-off-by: Stratos Karafotis
> > ---
> > drivers/cpufreq/cpufreq_conservative.c | 2 +-
> > drivers/cpufreq/cpufreq_governor.c | 46
> > +-
> > drivers/cpufreq/cpufreq_governor.h | 3 +--
> > drivers/cpufreq/cpufreq_ondemand.c | 11 +++-
> > 4 files changed, 29 insertions(+), 33 deletions(-)
> >
> > diff --git a/drivers/cpufreq/cpufreq_conservative.c
> > b/drivers/cpufreq/cpufreq_conservative.c
> > index 4fd0006..dfe652c 100644
> > --- a/drivers/cpufreq/cpufreq_conservative.c
> > +++ b/drivers/cpufreq/cpufreq_conservative.c
> > @@ -242,7 +242,7 @@ static ssize_t store_ignore_nice_load(struct kobject
> > *a, struct attribute *b,
> > struct cs_cpu_dbs_info_s *dbs_info;
> > dbs_info = _cpu(cs_cpu_dbs_info, j);
> > dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
> > -
> > _info->cdbs.prev_cpu_wall);
> > + _info->cdbs.prev_cpu_wall, 0);
> > if (cs_tuners.ignore_nice)
> > dbs_info->cdbs.prev_cpu_nice =
> > kcpustat_cpu(j).cpustat[CPUTIME_NICE];
> > diff --git a/drivers/cpufreq/cpufreq_governor.c
> > b/drivers/cpufreq/cpufreq_governor.c
> > index 5a76086..a322bda 100644
> > --- a/drivers/cpufreq/cpufreq_governor.c
> > +++ b/drivers/cpufreq/cpufreq_governor.c
> > @@ -50,13 +50,13 @@ static inline u64 get_cpu_idle_time_jiffy(unsigned int
> > cpu, u64 *wall)
> > return cputime_to_usecs(idle_time);
> > }
> >
> > -u64 get_cpu_idle_time(unsigned int cpu, u64 *wall)
> > +u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy)
> > {
> > u64 idle_time = get_cpu_idle_time_us(cpu, NULL);
> >
> > if (idle_time == -1ULL)
> > return get_cpu_idle_time_jiffy(cpu, wall);
> > - else
> > + else if (!io_busy)
> > idle_time += get_cpu_iowait_time_us(cpu, wall);
> >
> > return idle_time;
> > @@ -83,13 +83,22 @@ void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
> > /* Get Absolute Load (in terms of freq for ondemand gov) */
> > for_each_cpu(j, policy->cpus) {
> > struct cpu_dbs_common_info *j_cdbs;
> > - u64 cur_wall_time, cur_idle_time, cur_iowait_time;
> > - unsigned int idle_time, wall_time, iowait_time;
> > + u64 cur_wall_time, cur_idle_time;
> > + unsigned int idle_time, wall_time;
> > unsigned int load;
> > + int io_busy = 0;
> >
> > j_cdbs = dbs_data->get_cpu_cdbs(j);
> >
> > - cur_idle_time = get_cpu_idle_time(j, _wall_time);
> > + /*
> > +* For the purpose of ondemand, waiting for disk IO is
> > +* an indication that you're performance critical, and
> > +* not that the system is actually idle. So do not add
> > +* the iowait time to the cpu idle time.
> > +*/
> > + if (dbs_data->governor == GOV_ONDEMAND)
> > + io_busy = od_tuners->io_is_busy;
> > + cur_idle_time = get_cpu_idle_time(j, _wall_time,
> > io_busy);
> >
> > wall_time = (unsigned int)
> > (cur_wall_time - j_cdbs->prev_cpu_wall);
> > @@ -117,29 +126,6 @@ void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
> > idle_time += jiffies_to_usecs(cur_nice_jiffies);
> > }
> >
> > - if (dbs_data->governor == GOV_ONDEMAND) {
> > - struct od_cpu_dbs_info_s *od_j_dbs_info =
> > - dbs_data->get_cpu_dbs_info_s(cpu);
> > -
> > - cur_iowait_time = get_cpu_iowait_time_us(j,
> > - _wall_time);
> > - if (cur_iowait_time == -1ULL)
> > - cur_iowait_time = 0;
> > -
> > - iowait_time = (unsigned int) (cur_iowait_time -
> > - od_j_dbs_info->prev_cpu_iowait);
> > - od_j_dbs_info->prev_cpu_iowait = cur_iowait_time;
> > -
> > - /*
> > -* For the purpose of ondemand,
Re: [PATCH v2 linux-next] cpufreq: governors: Calculate iowait time only when necessary
On Friday, March 01, 2013 09:18:08 AM Viresh Kumar wrote:
On 28 February 2013 22:27, Stratos Karafotis strat...@semaphore.gr wrote:
Currently we always calculate the CPU iowait time and add it to idle time.
If we are in ondemand and we use io_is_busy, we re-calculate iowait time
and we subtract it from idle time.
With this patch iowait time is calculated only when necessary avoiding
the double call to get_cpu_iowait_time_us. We use a parameter in
function get_cpu_idle_time to distinguish when the iowait time will be
added to idle time or not, without the need of keeping the prev_io_wait.
Signed-off-by: Stratos Karafotis strat...@semaphore.gr
---
drivers/cpufreq/cpufreq_conservative.c | 2 +-
drivers/cpufreq/cpufreq_governor.c | 46
+-
drivers/cpufreq/cpufreq_governor.h | 3 +--
drivers/cpufreq/cpufreq_ondemand.c | 11 +++-
4 files changed, 29 insertions(+), 33 deletions(-)
diff --git a/drivers/cpufreq/cpufreq_conservative.c
b/drivers/cpufreq/cpufreq_conservative.c
index 4fd0006..dfe652c 100644
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -242,7 +242,7 @@ static ssize_t store_ignore_nice_load(struct kobject
*a, struct attribute *b,
struct cs_cpu_dbs_info_s *dbs_info;
dbs_info = per_cpu(cs_cpu_dbs_info, j);
dbs_info-cdbs.prev_cpu_idle = get_cpu_idle_time(j,
-
dbs_info-cdbs.prev_cpu_wall);
+ dbs_info-cdbs.prev_cpu_wall, 0);
if (cs_tuners.ignore_nice)
dbs_info-cdbs.prev_cpu_nice =
kcpustat_cpu(j).cpustat[CPUTIME_NICE];
diff --git a/drivers/cpufreq/cpufreq_governor.c
b/drivers/cpufreq/cpufreq_governor.c
index 5a76086..a322bda 100644
--- a/drivers/cpufreq/cpufreq_governor.c
+++ b/drivers/cpufreq/cpufreq_governor.c
@@ -50,13 +50,13 @@ static inline u64 get_cpu_idle_time_jiffy(unsigned int
cpu, u64 *wall)
return cputime_to_usecs(idle_time);
}
-u64 get_cpu_idle_time(unsigned int cpu, u64 *wall)
+u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy)
{
u64 idle_time = get_cpu_idle_time_us(cpu, NULL);
if (idle_time == -1ULL)
return get_cpu_idle_time_jiffy(cpu, wall);
- else
+ else if (!io_busy)
idle_time += get_cpu_iowait_time_us(cpu, wall);
return idle_time;
@@ -83,13 +83,22 @@ void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
/* Get Absolute Load (in terms of freq for ondemand gov) */
for_each_cpu(j, policy-cpus) {
struct cpu_dbs_common_info *j_cdbs;
- u64 cur_wall_time, cur_idle_time, cur_iowait_time;
- unsigned int idle_time, wall_time, iowait_time;
+ u64 cur_wall_time, cur_idle_time;
+ unsigned int idle_time, wall_time;
unsigned int load;
+ int io_busy = 0;
j_cdbs = dbs_data-get_cpu_cdbs(j);
- cur_idle_time = get_cpu_idle_time(j, cur_wall_time);
+ /*
+* For the purpose of ondemand, waiting for disk IO is
+* an indication that you're performance critical, and
+* not that the system is actually idle. So do not add
+* the iowait time to the cpu idle time.
+*/
+ if (dbs_data-governor == GOV_ONDEMAND)
+ io_busy = od_tuners-io_is_busy;
+ cur_idle_time = get_cpu_idle_time(j, cur_wall_time,
io_busy);
wall_time = (unsigned int)
(cur_wall_time - j_cdbs-prev_cpu_wall);
@@ -117,29 +126,6 @@ void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
idle_time += jiffies_to_usecs(cur_nice_jiffies);
}
- if (dbs_data-governor == GOV_ONDEMAND) {
- struct od_cpu_dbs_info_s *od_j_dbs_info =
- dbs_data-get_cpu_dbs_info_s(cpu);
-
- cur_iowait_time = get_cpu_iowait_time_us(j,
- cur_wall_time);
- if (cur_iowait_time == -1ULL)
- cur_iowait_time = 0;
-
- iowait_time = (unsigned int) (cur_iowait_time -
- od_j_dbs_info-prev_cpu_iowait);
- od_j_dbs_info-prev_cpu_iowait = cur_iowait_time;
-
- /*
-* For the purpose of ondemand, waiting for disk IO
is
-* an indication that you're performance critical,
and
-* not that the system
Re: [PATCH v2 linux-next] cpufreq: governors: Calculate iowait time only when necessary
On 28 February 2013 22:27, Stratos Karafotis wrote:
> Currently we always calculate the CPU iowait time and add it to idle time.
> If we are in ondemand and we use io_is_busy, we re-calculate iowait time
> and we subtract it from idle time.
>
> With this patch iowait time is calculated only when necessary avoiding
> the double call to get_cpu_iowait_time_us. We use a parameter in
> function get_cpu_idle_time to distinguish when the iowait time will be
> added to idle time or not, without the need of keeping the prev_io_wait.
>
> Signed-off-by: Stratos Karafotis
> ---
> drivers/cpufreq/cpufreq_conservative.c | 2 +-
> drivers/cpufreq/cpufreq_governor.c | 46
> +-
> drivers/cpufreq/cpufreq_governor.h | 3 +--
> drivers/cpufreq/cpufreq_ondemand.c | 11 +++-
> 4 files changed, 29 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/cpufreq/cpufreq_conservative.c
> b/drivers/cpufreq/cpufreq_conservative.c
> index 4fd0006..dfe652c 100644
> --- a/drivers/cpufreq/cpufreq_conservative.c
> +++ b/drivers/cpufreq/cpufreq_conservative.c
> @@ -242,7 +242,7 @@ static ssize_t store_ignore_nice_load(struct kobject *a,
> struct attribute *b,
> struct cs_cpu_dbs_info_s *dbs_info;
> dbs_info = _cpu(cs_cpu_dbs_info, j);
> dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
> -
> _info->cdbs.prev_cpu_wall);
> + _info->cdbs.prev_cpu_wall, 0);
> if (cs_tuners.ignore_nice)
> dbs_info->cdbs.prev_cpu_nice =
> kcpustat_cpu(j).cpustat[CPUTIME_NICE];
> diff --git a/drivers/cpufreq/cpufreq_governor.c
> b/drivers/cpufreq/cpufreq_governor.c
> index 5a76086..a322bda 100644
> --- a/drivers/cpufreq/cpufreq_governor.c
> +++ b/drivers/cpufreq/cpufreq_governor.c
> @@ -50,13 +50,13 @@ static inline u64 get_cpu_idle_time_jiffy(unsigned int
> cpu, u64 *wall)
> return cputime_to_usecs(idle_time);
> }
>
> -u64 get_cpu_idle_time(unsigned int cpu, u64 *wall)
> +u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy)
> {
> u64 idle_time = get_cpu_idle_time_us(cpu, NULL);
>
> if (idle_time == -1ULL)
> return get_cpu_idle_time_jiffy(cpu, wall);
> - else
> + else if (!io_busy)
> idle_time += get_cpu_iowait_time_us(cpu, wall);
>
> return idle_time;
> @@ -83,13 +83,22 @@ void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
> /* Get Absolute Load (in terms of freq for ondemand gov) */
> for_each_cpu(j, policy->cpus) {
> struct cpu_dbs_common_info *j_cdbs;
> - u64 cur_wall_time, cur_idle_time, cur_iowait_time;
> - unsigned int idle_time, wall_time, iowait_time;
> + u64 cur_wall_time, cur_idle_time;
> + unsigned int idle_time, wall_time;
> unsigned int load;
> + int io_busy = 0;
>
> j_cdbs = dbs_data->get_cpu_cdbs(j);
>
> - cur_idle_time = get_cpu_idle_time(j, _wall_time);
> + /*
> +* For the purpose of ondemand, waiting for disk IO is
> +* an indication that you're performance critical, and
> +* not that the system is actually idle. So do not add
> +* the iowait time to the cpu idle time.
> +*/
> + if (dbs_data->governor == GOV_ONDEMAND)
> + io_busy = od_tuners->io_is_busy;
> + cur_idle_time = get_cpu_idle_time(j, _wall_time, io_busy);
>
> wall_time = (unsigned int)
> (cur_wall_time - j_cdbs->prev_cpu_wall);
> @@ -117,29 +126,6 @@ void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
> idle_time += jiffies_to_usecs(cur_nice_jiffies);
> }
>
> - if (dbs_data->governor == GOV_ONDEMAND) {
> - struct od_cpu_dbs_info_s *od_j_dbs_info =
> - dbs_data->get_cpu_dbs_info_s(cpu);
> -
> - cur_iowait_time = get_cpu_iowait_time_us(j,
> - _wall_time);
> - if (cur_iowait_time == -1ULL)
> - cur_iowait_time = 0;
> -
> - iowait_time = (unsigned int) (cur_iowait_time -
> - od_j_dbs_info->prev_cpu_iowait);
> - od_j_dbs_info->prev_cpu_iowait = cur_iowait_time;
> -
> - /*
> -* For the purpose of ondemand, waiting for disk IO is
> -* an indication that you're performance critical, and
> -* not that the system is actually idle. So subtract
> the
> -* iowait time from the cpu idle time.
> -
Re: [PATCH v2 linux-next] cpufreq: governors: Calculate iowait time only when necessary
Hi Viresh,
On 02/28/2013 08:58 AM, Viresh Kumar wrote:
> I have really spent some 10-15 minutes reviewing this patch as initially it
> looked to me like something is missing here and calculations are going wrong.
>
> But it was fine :)
Thanks for you review.
>> diff --git a/drivers/cpufreq/cpufreq_ondemand.c
>> b/drivers/cpufreq/cpufreq_ondemand.c
>> index f3eb26c..46be2c4 100644
>> --- a/drivers/cpufreq/cpufreq_ondemand.c
>> +++ b/drivers/cpufreq/cpufreq_ondemand.c
>> @@ -339,11 +339,20 @@ static ssize_t store_io_is_busy(struct kobject *a,
>> struct attribute *b,
>> {
>
>> + /* we need to re-evaluate prev_cpu_idle */
>> + for_each_online_cpu(j) {
>> + struct od_cpu_dbs_info_s *dbs_info;
>> + dbs_info = _cpu(od_cpu_dbs_info, j);
>
> Probably squash above two lines and give a blank line after it.
>
>> + dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
>> + _info->cdbs.prev_cpu_wall, od_tuners.io_is_busy);
>> + }
>> return count;
>> }
>
> And after that add my:
>
> Acked-by: Viresh Kumar
>
Bellow V2 with your suggestion included.
Regards,
Stratos
8<--
Currently we always calculate the CPU iowait time and add it to idle time.
If we are in ondemand and we use io_is_busy, we re-calculate iowait time
and we subtract it from idle time.
With this patch iowait time is calculated only when necessary avoiding
the double call to get_cpu_iowait_time_us. We use a parameter in
function get_cpu_idle_time to distinguish when the iowait time will be
added to idle time or not, without the need of keeping the prev_io_wait.
Signed-off-by: Stratos Karafotis
---
drivers/cpufreq/cpufreq_conservative.c | 2 +-
drivers/cpufreq/cpufreq_governor.c | 46 +-
drivers/cpufreq/cpufreq_governor.h | 3 +--
drivers/cpufreq/cpufreq_ondemand.c | 11 +++-
4 files changed, 29 insertions(+), 33 deletions(-)
diff --git a/drivers/cpufreq/cpufreq_conservative.c
b/drivers/cpufreq/cpufreq_conservative.c
index 4fd0006..dfe652c 100644
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -242,7 +242,7 @@ static ssize_t store_ignore_nice_load(struct kobject *a,
struct attribute *b,
struct cs_cpu_dbs_info_s *dbs_info;
dbs_info = _cpu(cs_cpu_dbs_info, j);
dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
- _info->cdbs.prev_cpu_wall);
+ _info->cdbs.prev_cpu_wall, 0);
if (cs_tuners.ignore_nice)
dbs_info->cdbs.prev_cpu_nice =
kcpustat_cpu(j).cpustat[CPUTIME_NICE];
diff --git a/drivers/cpufreq/cpufreq_governor.c
b/drivers/cpufreq/cpufreq_governor.c
index 5a76086..a322bda 100644
--- a/drivers/cpufreq/cpufreq_governor.c
+++ b/drivers/cpufreq/cpufreq_governor.c
@@ -50,13 +50,13 @@ static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu,
u64 *wall)
return cputime_to_usecs(idle_time);
}
-u64 get_cpu_idle_time(unsigned int cpu, u64 *wall)
+u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy)
{
u64 idle_time = get_cpu_idle_time_us(cpu, NULL);
if (idle_time == -1ULL)
return get_cpu_idle_time_jiffy(cpu, wall);
- else
+ else if (!io_busy)
idle_time += get_cpu_iowait_time_us(cpu, wall);
return idle_time;
@@ -83,13 +83,22 @@ void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
/* Get Absolute Load (in terms of freq for ondemand gov) */
for_each_cpu(j, policy->cpus) {
struct cpu_dbs_common_info *j_cdbs;
- u64 cur_wall_time, cur_idle_time, cur_iowait_time;
- unsigned int idle_time, wall_time, iowait_time;
+ u64 cur_wall_time, cur_idle_time;
+ unsigned int idle_time, wall_time;
unsigned int load;
+ int io_busy = 0;
j_cdbs = dbs_data->get_cpu_cdbs(j);
- cur_idle_time = get_cpu_idle_time(j, _wall_time);
+ /*
+* For the purpose of ondemand, waiting for disk IO is
+* an indication that you're performance critical, and
+* not that the system is actually idle. So do not add
+* the iowait time to the cpu idle time.
+*/
+ if (dbs_data->governor == GOV_ONDEMAND)
+ io_busy = od_tuners->io_is_busy;
+ cur_idle_time = get_cpu_idle_time(j, _wall_time, io_busy);
wall_time = (unsigned int)
(cur_wall_time - j_cdbs->prev_cpu_wall);
@@ -117,29 +126,6 @@ void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
idle_time += jiffies_to_usecs(cur_nice_jiffies);
}
-
Re: [PATCH v2 linux-next] cpufreq: governors: Calculate iowait time only when necessary
Hi Viresh,
On 02/28/2013 08:58 AM, Viresh Kumar wrote:
I have really spent some 10-15 minutes reviewing this patch as initially it
looked to me like something is missing here and calculations are going wrong.
But it was fine :)
Thanks for you review.
diff --git a/drivers/cpufreq/cpufreq_ondemand.c
b/drivers/cpufreq/cpufreq_ondemand.c
index f3eb26c..46be2c4 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -339,11 +339,20 @@ static ssize_t store_io_is_busy(struct kobject *a,
struct attribute *b,
{
+ /* we need to re-evaluate prev_cpu_idle */
+ for_each_online_cpu(j) {
+ struct od_cpu_dbs_info_s *dbs_info;
+ dbs_info = per_cpu(od_cpu_dbs_info, j);
Probably squash above two lines and give a blank line after it.
+ dbs_info-cdbs.prev_cpu_idle = get_cpu_idle_time(j,
+ dbs_info-cdbs.prev_cpu_wall, od_tuners.io_is_busy);
+ }
return count;
}
And after that add my:
Acked-by: Viresh Kumar viresh.ku...@linaro.org
Bellow V2 with your suggestion included.
Regards,
Stratos
8--
Currently we always calculate the CPU iowait time and add it to idle time.
If we are in ondemand and we use io_is_busy, we re-calculate iowait time
and we subtract it from idle time.
With this patch iowait time is calculated only when necessary avoiding
the double call to get_cpu_iowait_time_us. We use a parameter in
function get_cpu_idle_time to distinguish when the iowait time will be
added to idle time or not, without the need of keeping the prev_io_wait.
Signed-off-by: Stratos Karafotis strat...@semaphore.gr
---
drivers/cpufreq/cpufreq_conservative.c | 2 +-
drivers/cpufreq/cpufreq_governor.c | 46 +-
drivers/cpufreq/cpufreq_governor.h | 3 +--
drivers/cpufreq/cpufreq_ondemand.c | 11 +++-
4 files changed, 29 insertions(+), 33 deletions(-)
diff --git a/drivers/cpufreq/cpufreq_conservative.c
b/drivers/cpufreq/cpufreq_conservative.c
index 4fd0006..dfe652c 100644
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -242,7 +242,7 @@ static ssize_t store_ignore_nice_load(struct kobject *a,
struct attribute *b,
struct cs_cpu_dbs_info_s *dbs_info;
dbs_info = per_cpu(cs_cpu_dbs_info, j);
dbs_info-cdbs.prev_cpu_idle = get_cpu_idle_time(j,
- dbs_info-cdbs.prev_cpu_wall);
+ dbs_info-cdbs.prev_cpu_wall, 0);
if (cs_tuners.ignore_nice)
dbs_info-cdbs.prev_cpu_nice =
kcpustat_cpu(j).cpustat[CPUTIME_NICE];
diff --git a/drivers/cpufreq/cpufreq_governor.c
b/drivers/cpufreq/cpufreq_governor.c
index 5a76086..a322bda 100644
--- a/drivers/cpufreq/cpufreq_governor.c
+++ b/drivers/cpufreq/cpufreq_governor.c
@@ -50,13 +50,13 @@ static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu,
u64 *wall)
return cputime_to_usecs(idle_time);
}
-u64 get_cpu_idle_time(unsigned int cpu, u64 *wall)
+u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy)
{
u64 idle_time = get_cpu_idle_time_us(cpu, NULL);
if (idle_time == -1ULL)
return get_cpu_idle_time_jiffy(cpu, wall);
- else
+ else if (!io_busy)
idle_time += get_cpu_iowait_time_us(cpu, wall);
return idle_time;
@@ -83,13 +83,22 @@ void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
/* Get Absolute Load (in terms of freq for ondemand gov) */
for_each_cpu(j, policy-cpus) {
struct cpu_dbs_common_info *j_cdbs;
- u64 cur_wall_time, cur_idle_time, cur_iowait_time;
- unsigned int idle_time, wall_time, iowait_time;
+ u64 cur_wall_time, cur_idle_time;
+ unsigned int idle_time, wall_time;
unsigned int load;
+ int io_busy = 0;
j_cdbs = dbs_data-get_cpu_cdbs(j);
- cur_idle_time = get_cpu_idle_time(j, cur_wall_time);
+ /*
+* For the purpose of ondemand, waiting for disk IO is
+* an indication that you're performance critical, and
+* not that the system is actually idle. So do not add
+* the iowait time to the cpu idle time.
+*/
+ if (dbs_data-governor == GOV_ONDEMAND)
+ io_busy = od_tuners-io_is_busy;
+ cur_idle_time = get_cpu_idle_time(j, cur_wall_time, io_busy);
wall_time = (unsigned int)
(cur_wall_time - j_cdbs-prev_cpu_wall);
@@ -117,29 +126,6 @@ void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
idle_time += jiffies_to_usecs(cur_nice_jiffies);
}
-
Re: [PATCH v2 linux-next] cpufreq: governors: Calculate iowait time only when necessary
On 28 February 2013 22:27, Stratos Karafotis strat...@semaphore.gr wrote:
Currently we always calculate the CPU iowait time and add it to idle time.
If we are in ondemand and we use io_is_busy, we re-calculate iowait time
and we subtract it from idle time.
With this patch iowait time is calculated only when necessary avoiding
the double call to get_cpu_iowait_time_us. We use a parameter in
function get_cpu_idle_time to distinguish when the iowait time will be
added to idle time or not, without the need of keeping the prev_io_wait.
Signed-off-by: Stratos Karafotis strat...@semaphore.gr
---
drivers/cpufreq/cpufreq_conservative.c | 2 +-
drivers/cpufreq/cpufreq_governor.c | 46
+-
drivers/cpufreq/cpufreq_governor.h | 3 +--
drivers/cpufreq/cpufreq_ondemand.c | 11 +++-
4 files changed, 29 insertions(+), 33 deletions(-)
diff --git a/drivers/cpufreq/cpufreq_conservative.c
b/drivers/cpufreq/cpufreq_conservative.c
index 4fd0006..dfe652c 100644
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -242,7 +242,7 @@ static ssize_t store_ignore_nice_load(struct kobject *a,
struct attribute *b,
struct cs_cpu_dbs_info_s *dbs_info;
dbs_info = per_cpu(cs_cpu_dbs_info, j);
dbs_info-cdbs.prev_cpu_idle = get_cpu_idle_time(j,
-
dbs_info-cdbs.prev_cpu_wall);
+ dbs_info-cdbs.prev_cpu_wall, 0);
if (cs_tuners.ignore_nice)
dbs_info-cdbs.prev_cpu_nice =
kcpustat_cpu(j).cpustat[CPUTIME_NICE];
diff --git a/drivers/cpufreq/cpufreq_governor.c
b/drivers/cpufreq/cpufreq_governor.c
index 5a76086..a322bda 100644
--- a/drivers/cpufreq/cpufreq_governor.c
+++ b/drivers/cpufreq/cpufreq_governor.c
@@ -50,13 +50,13 @@ static inline u64 get_cpu_idle_time_jiffy(unsigned int
cpu, u64 *wall)
return cputime_to_usecs(idle_time);
}
-u64 get_cpu_idle_time(unsigned int cpu, u64 *wall)
+u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy)
{
u64 idle_time = get_cpu_idle_time_us(cpu, NULL);
if (idle_time == -1ULL)
return get_cpu_idle_time_jiffy(cpu, wall);
- else
+ else if (!io_busy)
idle_time += get_cpu_iowait_time_us(cpu, wall);
return idle_time;
@@ -83,13 +83,22 @@ void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
/* Get Absolute Load (in terms of freq for ondemand gov) */
for_each_cpu(j, policy-cpus) {
struct cpu_dbs_common_info *j_cdbs;
- u64 cur_wall_time, cur_idle_time, cur_iowait_time;
- unsigned int idle_time, wall_time, iowait_time;
+ u64 cur_wall_time, cur_idle_time;
+ unsigned int idle_time, wall_time;
unsigned int load;
+ int io_busy = 0;
j_cdbs = dbs_data-get_cpu_cdbs(j);
- cur_idle_time = get_cpu_idle_time(j, cur_wall_time);
+ /*
+* For the purpose of ondemand, waiting for disk IO is
+* an indication that you're performance critical, and
+* not that the system is actually idle. So do not add
+* the iowait time to the cpu idle time.
+*/
+ if (dbs_data-governor == GOV_ONDEMAND)
+ io_busy = od_tuners-io_is_busy;
+ cur_idle_time = get_cpu_idle_time(j, cur_wall_time, io_busy);
wall_time = (unsigned int)
(cur_wall_time - j_cdbs-prev_cpu_wall);
@@ -117,29 +126,6 @@ void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
idle_time += jiffies_to_usecs(cur_nice_jiffies);
}
- if (dbs_data-governor == GOV_ONDEMAND) {
- struct od_cpu_dbs_info_s *od_j_dbs_info =
- dbs_data-get_cpu_dbs_info_s(cpu);
-
- cur_iowait_time = get_cpu_iowait_time_us(j,
- cur_wall_time);
- if (cur_iowait_time == -1ULL)
- cur_iowait_time = 0;
-
- iowait_time = (unsigned int) (cur_iowait_time -
- od_j_dbs_info-prev_cpu_iowait);
- od_j_dbs_info-prev_cpu_iowait = cur_iowait_time;
-
- /*
-* For the purpose of ondemand, waiting for disk IO is
-* an indication that you're performance critical, and
-* not that the system is actually idle. So subtract
the
-* iowait time from the cpu idle time.
-*/
- if
