2024-03-31 16:05:40

by Vitalii Bursov

Subject: [PATCH v2 1/3] sched/fair: allow disabling sched_balance_newidle with sched_relax_domain_level

Change relax_domain_level checks so that it would be possible
to include or exclude all domains from newidle balancing.

This matches the behavior described in the documentation:
-1 no request. use system default or follow request of others.
0 no search.
1 search siblings (hyperthreads in a core).

"2" enables levels 0 and 1, level_max excludes the last (level_max)
level, and level_max+1 includes all levels.

Fixes: 9ae7ab20b483 ("sched/topology: Don't set SD_BALANCE_WAKE on cpuset domain relax")
Signed-off-by: Vitalii Bursov <[email protected]>
---
kernel/cgroup/cpuset.c | 2 +-
kernel/sched/topology.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 4237c8748..da24187c4 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -2948,7 +2948,7 @@ bool current_cpuset_is_being_rebound(void)
static int update_relax_domain_level(struct cpuset *cs, s64 val)
{
#ifdef CONFIG_SMP
- if (val < -1 || val >= sched_domain_level_max)
+ if (val < -1 || val > sched_domain_level_max + 1)
return -EINVAL;
#endif

diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 63aecd2a7..67a777b31 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -1475,7 +1475,7 @@ static void set_domain_attribute(struct sched_domain *sd,
} else
request = attr->relax_domain_level;

- if (sd->level > request) {
+ if (sd->level >= request) {
/* Turn off idle balance on this domain: */
sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE);
}
--
2.20.1

2024-04-01 10:24:03

by Vincent Guittot

Subject: Re: [PATCH v2 1/3] sched/fair: allow disabling sched_balance_newidle with sched_relax_domain_level

On Sun, 31 Mar 2024 at 18:02, Vitalii Bursov <[email protected]> wrote:
>
> Change relax_domain_level checks so that it would be possible
> to include or exclude all domains from newidle balancing.
>
> This matches the behavior described in the documentation:
> -1 no request. use system default or follow request of others.
> 0 no search.
> 1 search siblings (hyperthreads in a core).
>
> "2" enables levels 0 and 1, level_max excludes the last (level_max)
> level, and level_max+1 includes all levels.
>
> Fixes: 9ae7ab20b483 ("sched/topology: Don't set SD_BALANCE_WAKE on cpuset domain relax")
> Signed-off-by: Vitalii Bursov <[email protected]>

Reviewed-by: Vincent Guittot <[email protected]>

> ---
> kernel/cgroup/cpuset.c | 2 +-
> kernel/sched/topology.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
> index 4237c8748..da24187c4 100644
> --- a/kernel/cgroup/cpuset.c
> +++ b/kernel/cgroup/cpuset.c
> @@ -2948,7 +2948,7 @@ bool current_cpuset_is_being_rebound(void)
> static int update_relax_domain_level(struct cpuset *cs, s64 val)
> {
> #ifdef CONFIG_SMP
> - if (val < -1 || val >= sched_domain_level_max)
> + if (val < -1 || val > sched_domain_level_max + 1)
> return -EINVAL;
> #endif
>
> diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
> index 63aecd2a7..67a777b31 100644
> --- a/kernel/sched/topology.c
> +++ b/kernel/sched/topology.c
> @@ -1475,7 +1475,7 @@ static void set_domain_attribute(struct sched_domain *sd,
> } else
> request = attr->relax_domain_level;
>
> - if (sd->level > request) {
> + if (sd->level >= request) {
> /* Turn off idle balance on this domain: */
> sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE);
> }
> --
> 2.20.1
>