Now cpu.uclamp.min acts as a protection, we need to make sure that the
uclamp request of the task is within the allowed range of the cgroup,
that is it is clamp()'ed correctly by tg->uclamp[UCLAMP_MIN] and
tg->uclamp[UCLAMP_MAX].
As reported by Xuewen [1] we can have some corner cases where there's
inverstion between uclamp requested by task (p) and the uclamp values of
the taskgroup it's attached to (tg). Following table demonstrates
2 corner cases:
| p | tg | effective
-----------+-----+------+-----------
CASE 1
-----------+-----+------+-----------
uclamp_min | 60% | 0% | 60%
-----------+-----+------+-----------
uclamp_max | 80% | 50% | 50%
-----------+-----+------+-----------
CASE 2
-----------+-----+------+-----------
uclamp_min | 0% | 30% | 30%
-----------+-----+------+-----------
uclamp_max | 20% | 50% | 20%
-----------+-----+------+-----------
With this fix we get:
| p | tg | effective
-----------+-----+------+-----------
CASE 1
-----------+-----+------+-----------
uclamp_min | 60% | 0% | 50%
-----------+-----+------+-----------
uclamp_max | 80% | 50% | 50%
-----------+-----+------+-----------
CASE 2
-----------+-----+------+-----------
uclamp_min | 0% | 30% | 30%
-----------+-----+------+-----------
uclamp_max | 20% | 50% | 30%
-----------+-----+------+-----------
Additionally uclamp_update_active_tasks() must now unconditionally
update both UCLAMP_MIN/MAX because changing the tg's UCLAMP_MAX for
instance could have an impact on the effective UCLAMP_MIN of the tasks.
| p | tg | effective
-----------+-----+------+-----------
old
-----------+-----+------+-----------
uclamp_min | 60% | 0% | 50%
-----------+-----+------+-----------
uclamp_max | 80% | 50% | 50%
-----------+-----+------+-----------
*new*
-----------+-----+------+-----------
uclamp_min | 60% | 0% | *60%*
-----------+-----+------+-----------
uclamp_max | 80% |*70%* | *70%*
-----------+-----+------+-----------
[1] https://lore.kernel.org/lkml/CAB8ipk_a6VFNjiEnHRHkUMBKbA+qzPQvhtNjJ_YNzQhqV_o8Zw@mail.gmail.com/
Reported-by: Xuewen Yan <[email protected]>
Fixes: 0c18f2ecfcc2 ("sched/uclamp: Fix wrong implementation of cpu.uclamp.min")
Signed-off-by: Qais Yousef <[email protected]>
---
Xuewen, Yun, Wei
If you can give this a spin and provide Tested-by that would be much
appreciated.
Thanks!
kernel/sched/core.c | 43 +++++++++++++++----------------------------
1 file changed, 15 insertions(+), 28 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 9e9a5be35cde..0318b00baa97 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1403,38 +1403,28 @@ static void uclamp_sync_util_min_rt_default(void)
static inline struct uclamp_se
uclamp_tg_restrict(struct task_struct *p, enum uclamp_id clamp_id)
{
- struct uclamp_se uc_req = p->uclamp_req[clamp_id];
+ /* Copy by value as we could modify it */
+ struct uclamp_se uc_eff = p->uclamp_req[clamp_id];
#ifdef CONFIG_UCLAMP_TASK_GROUP
+ unsigned int tg_min, tg_max, value;
/*
* Tasks in autogroups or root task group will be
* restricted by system defaults.
*/
if (task_group_is_autogroup(task_group(p)))
- return uc_req;
+ return uc_eff;
if (task_group(p) == &root_task_group)
- return uc_req;
+ return uc_eff;
- switch (clamp_id) {
- case UCLAMP_MIN: {
- struct uclamp_se uc_min = task_group(p)->uclamp[clamp_id];
- if (uc_req.value < uc_min.value)
- return uc_min;
- break;
- }
- case UCLAMP_MAX: {
- struct uclamp_se uc_max = task_group(p)->uclamp[clamp_id];
- if (uc_req.value > uc_max.value)
- return uc_max;
- break;
- }
- default:
- WARN_ON_ONCE(1);
- break;
- }
+ tg_min = task_group(p)->uclamp[UCLAMP_MIN].value;
+ tg_max = task_group(p)->uclamp[UCLAMP_MAX].value;
+ value = uc_eff.value;
+ value = clamp(value, tg_min, tg_max);
+ uclamp_se_set(&uc_eff, value, false);
#endif
- return uc_req;
+ return uc_eff;
}
/*
@@ -1661,8 +1651,7 @@ uclamp_update_active(struct task_struct *p, enum uclamp_id clamp_id)
#ifdef CONFIG_UCLAMP_TASK_GROUP
static inline void
-uclamp_update_active_tasks(struct cgroup_subsys_state *css,
- unsigned int clamps)
+uclamp_update_active_tasks(struct cgroup_subsys_state *css)
{
enum uclamp_id clamp_id;
struct css_task_iter it;
@@ -1670,10 +1659,8 @@ uclamp_update_active_tasks(struct cgroup_subsys_state *css,
css_task_iter_start(css, 0, &it);
while ((p = css_task_iter_next(&it))) {
- for_each_clamp_id(clamp_id) {
- if ((0x1 << clamp_id) & clamps)
- uclamp_update_active(p, clamp_id);
- }
+ for_each_clamp_id(clamp_id)
+ uclamp_update_active(p, clamp_id);
}
css_task_iter_end(&it);
}
@@ -9626,7 +9613,7 @@ static void cpu_util_update_eff(struct cgroup_subsys_state *css)
}
/* Immediately update descendants RUNNABLE tasks */
- uclamp_update_active_tasks(css, clamps);
+ uclamp_update_active_tasks(css);
}
}
--
2.25.1
Hi Qais
Sorry for the late reply.
I tested the patch on the "UNISOC T610" platform, and it looks fine.
According to the two cases:
case1:
without patch:
set task's clamp_min=614(60%), clamp_max=819(80%), the result as:
[ 215.780435]c6 uclamp_test :
pid=138,req_min=614,req_max=819,eff_min=614,eff_max=819
after set tg's cpu.uclamp.max = 50%，the result:
[ 420.580443]c6 uclamp_test :
pid=138,req_min=614,req_max=819,eff_min=614,eff_max=512
with patch:
set task's clamp_min=614(60%), clamp_max=819(80%), the result as:
[ 333.533878]c7 uclamp_test :
pid=138,req_min=614,req_max=819,eff_min=614,eff_max=819
after set tg's cpu.uclamp.max = 50%，the result:
[ 430.813789]c6 uclamp_test :
pid=138,req_min=614,req_max=819,eff_min=512,eff_max=512
case2:
without patch:
set task's clamp_min=614(60%), clamp_max=819(80%), the result as:
[ 169.700544]c0 uclamp_test :
pid=137,req_min=0,req_max=209,eff_min=0,eff_max=209
after set tg's cpu.uclamp.min = 30%, tg's cpu.uclamp.max = 50%，the result:
[ 246.500634]c7 uclamp_test :
pid=137,req_min=0,req_max=209,eff_min=307,eff_max=209
with patch:
set task's clamp_min=0(0%), clamp_max=209(20%), the result as:
[ 169.700544]c0 uclamp_test :
pid=137,req_min=0,req_max=209,eff_min=0,eff_max=209
after set tg's cpu.uclamp.min = 30%, tg's cpu.uclamp.max = 50%，the result:
[ 179.933868]c6 uclamp_test :
pid=137,req_min=0,req_max=209,eff_min=307,eff_max=307
---
Cheers
xuewen
On Fri, Jun 11, 2021 at 8:23 PM Qais Yousef <[email protected]> wrote:
>
> Now cpu.uclamp.min acts as a protection, we need to make sure that the
> uclamp request of the task is within the allowed range of the cgroup,
> that is it is clamp()'ed correctly by tg->uclamp[UCLAMP_MIN] and
> tg->uclamp[UCLAMP_MAX].
>
> As reported by Xuewen [1] we can have some corner cases where there's
> inverstion between uclamp requested by task (p) and the uclamp values of
> the taskgroup it's attached to (tg). Following table demonstrates
> 2 corner cases:
>
> | p | tg | effective
> -----------+-----+------+-----------
> CASE 1
> -----------+-----+------+-----------
> uclamp_min | 60% | 0% | 60%
> -----------+-----+------+-----------
> uclamp_max | 80% | 50% | 50%
> -----------+-----+------+-----------
> CASE 2
> -----------+-----+------+-----------
> uclamp_min | 0% | 30% | 30%
> -----------+-----+------+-----------
> uclamp_max | 20% | 50% | 20%
> -----------+-----+------+-----------
>
> With this fix we get:
>
> | p | tg | effective
> -----------+-----+------+-----------
> CASE 1
> -----------+-----+------+-----------
> uclamp_min | 60% | 0% | 50%
> -----------+-----+------+-----------
> uclamp_max | 80% | 50% | 50%
> -----------+-----+------+-----------
> CASE 2
> -----------+-----+------+-----------
> uclamp_min | 0% | 30% | 30%
> -----------+-----+------+-----------
> uclamp_max | 20% | 50% | 30%
> -----------+-----+------+-----------
>
> Additionally uclamp_update_active_tasks() must now unconditionally
> update both UCLAMP_MIN/MAX because changing the tg's UCLAMP_MAX for
> instance could have an impact on the effective UCLAMP_MIN of the tasks.
>
> | p | tg | effective
> -----------+-----+------+-----------
> old
> -----------+-----+------+-----------
> uclamp_min | 60% | 0% | 50%
> -----------+-----+------+-----------
> uclamp_max | 80% | 50% | 50%
> -----------+-----+------+-----------
> *new*
> -----------+-----+------+-----------
> uclamp_min | 60% | 0% | *60%*
> -----------+-----+------+-----------
> uclamp_max | 80% |*70%* | *70%*
> -----------+-----+------+-----------
>
> [1] https://lore.kernel.org/lkml/CAB8ipk_a6VFNjiEnHRHkUMBKbA+qzPQvhtNjJ_YNzQhqV_o8Zw@mail.gmail.com/
>
> Reported-by: Xuewen Yan <[email protected]>
> Fixes: 0c18f2ecfcc2 ("sched/uclamp: Fix wrong implementation of cpu.uclamp.min")
> Signed-off-by: Qais Yousef <[email protected]>
> ---
>
> Xuewen, Yun, Wei
>
> If you can give this a spin and provide Tested-by that would be much
> appreciated.
>
> Thanks!
>
>
> kernel/sched/core.c | 43 +++++++++++++++----------------------------
> 1 file changed, 15 insertions(+), 28 deletions(-)
>
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 9e9a5be35cde..0318b00baa97 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -1403,38 +1403,28 @@ static void uclamp_sync_util_min_rt_default(void)
> static inline struct uclamp_se
> uclamp_tg_restrict(struct task_struct *p, enum uclamp_id clamp_id)
> {
> - struct uclamp_se uc_req = p->uclamp_req[clamp_id];
> + /* Copy by value as we could modify it */
> + struct uclamp_se uc_eff = p->uclamp_req[clamp_id];
> #ifdef CONFIG_UCLAMP_TASK_GROUP
> + unsigned int tg_min, tg_max, value;
>
> /*
> * Tasks in autogroups or root task group will be
> * restricted by system defaults.
> */
> if (task_group_is_autogroup(task_group(p)))
> - return uc_req;
> + return uc_eff;
> if (task_group(p) == &root_task_group)
> - return uc_req;
> + return uc_eff;
>
> - switch (clamp_id) {
> - case UCLAMP_MIN: {
> - struct uclamp_se uc_min = task_group(p)->uclamp[clamp_id];
> - if (uc_req.value < uc_min.value)
> - return uc_min;
> - break;
> - }
> - case UCLAMP_MAX: {
> - struct uclamp_se uc_max = task_group(p)->uclamp[clamp_id];
> - if (uc_req.value > uc_max.value)
> - return uc_max;
> - break;
> - }
> - default:
> - WARN_ON_ONCE(1);
> - break;
> - }
> + tg_min = task_group(p)->uclamp[UCLAMP_MIN].value;
> + tg_max = task_group(p)->uclamp[UCLAMP_MAX].value;
> + value = uc_eff.value;
> + value = clamp(value, tg_min, tg_max);
> + uclamp_se_set(&uc_eff, value, false);
> #endif
>
> - return uc_req;
> + return uc_eff;
> }
>
> /*
> @@ -1661,8 +1651,7 @@ uclamp_update_active(struct task_struct *p, enum uclamp_id clamp_id)
>
> #ifdef CONFIG_UCLAMP_TASK_GROUP
> static inline void
> -uclamp_update_active_tasks(struct cgroup_subsys_state *css,
> - unsigned int clamps)
> +uclamp_update_active_tasks(struct cgroup_subsys_state *css)
> {
> enum uclamp_id clamp_id;
> struct css_task_iter it;
> @@ -1670,10 +1659,8 @@ uclamp_update_active_tasks(struct cgroup_subsys_state *css,
>
> css_task_iter_start(css, 0, &it);
> while ((p = css_task_iter_next(&it))) {
> - for_each_clamp_id(clamp_id) {
> - if ((0x1 << clamp_id) & clamps)
> - uclamp_update_active(p, clamp_id);
> - }
> + for_each_clamp_id(clamp_id)
> + uclamp_update_active(p, clamp_id);
> }
> css_task_iter_end(&it);
> }
> @@ -9626,7 +9613,7 @@ static void cpu_util_update_eff(struct cgroup_subsys_state *css)
> }
>
> /* Immediately update descendants RUNNABLE tasks */
> - uclamp_update_active_tasks(css, clamps);
> + uclamp_update_active_tasks(css);
> }
> }
>
> --
> 2.25.1
>
On 11/06/2021 14:22, Qais Yousef wrote:
> Now cpu.uclamp.min acts as a protection, we need to make sure that the
> uclamp request of the task is within the allowed range of the cgroup,
> that is it is clamp()'ed correctly by tg->uclamp[UCLAMP_MIN] and
> tg->uclamp[UCLAMP_MAX].
>
> As reported by Xuewen [1] we can have some corner cases where there's
> inverstion between uclamp requested by task (p) and the uclamp values of
s/inverstion/inversion
[...]
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 9e9a5be35cde..0318b00baa97 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -1403,38 +1403,28 @@ static void uclamp_sync_util_min_rt_default(void)
> static inline struct uclamp_se
> uclamp_tg_restrict(struct task_struct *p, enum uclamp_id clamp_id)
> {
> - struct uclamp_se uc_req = p->uclamp_req[clamp_id];
> + /* Copy by value as we could modify it */
> + struct uclamp_se uc_eff = p->uclamp_req[clamp_id];
> #ifdef CONFIG_UCLAMP_TASK_GROUP
> + unsigned int tg_min, tg_max, value;
>
> /*
> * Tasks in autogroups or root task group will be
> * restricted by system defaults.
> */
> if (task_group_is_autogroup(task_group(p)))
> - return uc_req;
> + return uc_eff;
> if (task_group(p) == &root_task_group)
> - return uc_req;
> + return uc_eff;
>
> - switch (clamp_id) {
> - case UCLAMP_MIN: {
> - struct uclamp_se uc_min = task_group(p)->uclamp[clamp_id];
> - if (uc_req.value < uc_min.value)
> - return uc_min;
> - break;
> - }
> - case UCLAMP_MAX: {
> - struct uclamp_se uc_max = task_group(p)->uclamp[clamp_id];
> - if (uc_req.value > uc_max.value)
> - return uc_max;
> - break;
> - }
> - default:
> - WARN_ON_ONCE(1);
> - break;
> - }
> + tg_min = task_group(p)->uclamp[UCLAMP_MIN].value;
> + tg_max = task_group(p)->uclamp[UCLAMP_MAX].value;
> + value = uc_eff.value;
> + value = clamp(value, tg_min, tg_max);
> + uclamp_se_set(&uc_eff, value, false);
> #endif
>
> - return uc_req;
> + return uc_eff;
> }
I got confused by the renaming uc_req -> uc_eff.
We have:
uclamp_eff_value() (1)
uclamp_se uc_eff = uclamp_eff_get(p, clamp_id); (2)
uclamp_se uc_req = uclamp_tg_restrict(p, clamp_id) (3)
struct uclamp_se uc_eff = p->uclamp_req[clamp_id];
....
(3) is now calling it uc_eff where (2) still uses uc_req for the return
of (3). IMHO uc_*eff* was used after the system level (
uclamp_default) have been applied.
[...]
> @@ -1670,10 +1659,8 @@ uclamp_update_active_tasks(struct cgroup_subsys_state *css,
>
> css_task_iter_start(css, 0, &it);
> while ((p = css_task_iter_next(&it))) {
> - for_each_clamp_id(clamp_id) {
> - if ((0x1 << clamp_id) & clamps)
> - uclamp_update_active(p, clamp_id);
> - }
> + for_each_clamp_id(clamp_id)
> + uclamp_update_active(p, clamp_id);
> }
> css_task_iter_end(&it);
> }
> @@ -9626,7 +9613,7 @@ static void cpu_util_update_eff(struct cgroup_subsys_state *css)
> }
>
> /* Immediately update descendants RUNNABLE tasks */
> - uclamp_update_active_tasks(css, clamps);
> + uclamp_update_active_tasks(css);
Since we now always have to update both clamp_id's, can you not update
both under the same task_rq_lock() (in uclamp_update_active())?
Hi Xuewen
On 06/16/21 11:06, Xuewen Yan wrote:
> Hi Qais
>
> Sorry for the late reply.
>
> I tested the patch on the "UNISOC T610" platform, and it looks fine.
>
> According to the two cases:
> case1:
> without patch:
> set task's clamp_min=614(60%), clamp_max=819(80%), the result as:
> [ 215.780435]c6 uclamp_test :
> pid=138,req_min=614,req_max=819,eff_min=614,eff_max=819
>
> after set tg's cpu.uclamp.max = 50%，the result:
> [ 420.580443]c6 uclamp_test :
> pid=138,req_min=614,req_max=819,eff_min=614,eff_max=512
>
> with patch:
> set task's clamp_min=614(60%), clamp_max=819(80%), the result as:
> [ 333.533878]c7 uclamp_test :
> pid=138,req_min=614,req_max=819,eff_min=614,eff_max=819
>
> after set tg's cpu.uclamp.max = 50%，the result:
> [ 430.813789]c6 uclamp_test :
> pid=138,req_min=614,req_max=819,eff_min=512,eff_max=512
>
> case2:
> without patch:
> set task's clamp_min=614(60%), clamp_max=819(80%), the result as:
> [ 169.700544]c0 uclamp_test :
> pid=137,req_min=0,req_max=209,eff_min=0,eff_max=209
>
> after set tg's cpu.uclamp.min = 30%, tg's cpu.uclamp.max = 50%，the result:
> [ 246.500634]c7 uclamp_test :
> pid=137,req_min=0,req_max=209,eff_min=307,eff_max=209
>
> with patch:
> set task's clamp_min=0(0%), clamp_max=209(20%), the result as:
> [ 169.700544]c0 uclamp_test :
> pid=137,req_min=0,req_max=209,eff_min=0,eff_max=209
>
> after set tg's cpu.uclamp.min = 30%, tg's cpu.uclamp.max = 50%，the result:
> [ 179.933868]c6 uclamp_test :
> pid=137,req_min=0,req_max=209,eff_min=307,eff_max=307
Thanks a lot for trying it out.
Cheers
--
Qais Yousef
On 06/16/21 19:09, Dietmar Eggemann wrote:
> On 11/06/2021 14:22, Qais Yousef wrote:
> > Now cpu.uclamp.min acts as a protection, we need to make sure that the
> > uclamp request of the task is within the allowed range of the cgroup,
> > that is it is clamp()'ed correctly by tg->uclamp[UCLAMP_MIN] and
> > tg->uclamp[UCLAMP_MAX].
> >
> > As reported by Xuewen [1] we can have some corner cases where there's
> > inverstion between uclamp requested by task (p) and the uclamp values of
>
> s/inverstion/inversion
Fixed.
>
> [...]
>
> > diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> > index 9e9a5be35cde..0318b00baa97 100644
> > --- a/kernel/sched/core.c
> > +++ b/kernel/sched/core.c
> > @@ -1403,38 +1403,28 @@ static void uclamp_sync_util_min_rt_default(void)
> > static inline struct uclamp_se
> > uclamp_tg_restrict(struct task_struct *p, enum uclamp_id clamp_id)
> > {
> > - struct uclamp_se uc_req = p->uclamp_req[clamp_id];
> > + /* Copy by value as we could modify it */
> > + struct uclamp_se uc_eff = p->uclamp_req[clamp_id];
> > #ifdef CONFIG_UCLAMP_TASK_GROUP
> > + unsigned int tg_min, tg_max, value;
> >
> > /*
> > * Tasks in autogroups or root task group will be
> > * restricted by system defaults.
> > */
> > if (task_group_is_autogroup(task_group(p)))
> > - return uc_req;
> > + return uc_eff;
> > if (task_group(p) == &root_task_group)
> > - return uc_req;
> > + return uc_eff;
> >
> > - switch (clamp_id) {
> > - case UCLAMP_MIN: {
> > - struct uclamp_se uc_min = task_group(p)->uclamp[clamp_id];
> > - if (uc_req.value < uc_min.value)
> > - return uc_min;
> > - break;
> > - }
> > - case UCLAMP_MAX: {
> > - struct uclamp_se uc_max = task_group(p)->uclamp[clamp_id];
> > - if (uc_req.value > uc_max.value)
> > - return uc_max;
> > - break;
> > - }
> > - default:
> > - WARN_ON_ONCE(1);
> > - break;
> > - }
> > + tg_min = task_group(p)->uclamp[UCLAMP_MIN].value;
> > + tg_max = task_group(p)->uclamp[UCLAMP_MAX].value;
> > + value = uc_eff.value;
> > + value = clamp(value, tg_min, tg_max);
> > + uclamp_se_set(&uc_eff, value, false);
> > #endif
> >
> > - return uc_req;
> > + return uc_eff;
> > }
>
> I got confused by the renaming uc_req -> uc_eff.
>
> We have:
>
> uclamp_eff_value() (1)
>
> uclamp_se uc_eff = uclamp_eff_get(p, clamp_id); (2)
>
> uclamp_se uc_req = uclamp_tg_restrict(p, clamp_id) (3)
>
> struct uclamp_se uc_eff = p->uclamp_req[clamp_id];
> ....
>
> (3) is now calling it uc_eff where (2) still uses uc_req for the return
> of (3). IMHO uc_*eff* was used after the system level (
> uclamp_default) have been applied.
Renamed it back to uc_req.
>
> [...]
>
> > @@ -1670,10 +1659,8 @@ uclamp_update_active_tasks(struct cgroup_subsys_state *css,
> >
> > css_task_iter_start(css, 0, &it);
> > while ((p = css_task_iter_next(&it))) {
> > - for_each_clamp_id(clamp_id) {
> > - if ((0x1 << clamp_id) & clamps)
> > - uclamp_update_active(p, clamp_id);
> > - }
> > + for_each_clamp_id(clamp_id)
> > + uclamp_update_active(p, clamp_id);
> > }
> > css_task_iter_end(&it);
> > }
> > @@ -9626,7 +9613,7 @@ static void cpu_util_update_eff(struct cgroup_subsys_state *css)
> > }
> >
> > /* Immediately update descendants RUNNABLE tasks */
> > - uclamp_update_active_tasks(css, clamps);
> > + uclamp_update_active_tasks(css);
>
> Since we now always have to update both clamp_id's, can you not update
> both under the same task_rq_lock() (in uclamp_update_active())?
Good idea. Done this
--->8---
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index b4e856a4335d..fdb9a109fd68 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1620,8 +1620,9 @@ static inline void uclamp_rq_dec(struct rq *rq, struct task_struct *p)
}
static inline void
-uclamp_update_active(struct task_struct *p, enum uclamp_id clamp_id)
+uclamp_update_active(struct task_struct *p)
{
+ enum uclamp_id clamp_id;
struct rq_flags rf;
struct rq *rq;
@@ -1641,9 +1642,11 @@ uclamp_update_active(struct task_struct *p, enum uclamp_id clamp_id)
* affecting a valid clamp bucket, the next time it's enqueued,
* it will already see the updated clamp bucket value.
*/
- if (p->uclamp[clamp_id].active) {
- uclamp_rq_dec_id(rq, p, clamp_id);
- uclamp_rq_inc_id(rq, p, clamp_id);
+ for_each_clamp_id(clamp_id) {
+ if (p->uclamp[clamp_id].active) {
+ uclamp_rq_dec_id(rq, p, clamp_id);
+ uclamp_rq_inc_id(rq, p, clamp_id);
+ }
}
task_rq_unlock(rq, p, &rf);
@@ -1653,15 +1656,12 @@ uclamp_update_active(struct task_struct *p, enum uclamp_id clamp_id)
static inline void
uclamp_update_active_tasks(struct cgroup_subsys_state *css)
{
- enum uclamp_id clamp_id;
struct css_task_iter it;
struct task_struct *p;
css_task_iter_start(css, 0, &it);
- while ((p = css_task_iter_next(&it))) {
- for_each_clamp_id(clamp_id)
- uclamp_update_active(p, clamp_id);
- }
+ while ((p = css_task_iter_next(&it)))
+ uclamp_update_active(p);
css_task_iter_end(&it);
}
--->8---
Thanks!
--
Qais Yousef