2023-06-08 09:15:40

by suhua

Subject: [PATCH] cgroup/cpuset: Fix comment in cpuset_hotplug_workfn

"synchronize cpus_allowed to cpu_active_mask"
-> "synchronize cpu_active_mask to cpus_allowed"

Signed-off-by: suhua <[email protected]>
---
kernel/cgroup/cpuset.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index b0aee733b92b..4810d29e2d63 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -3739,7 +3739,7 @@ static void cpuset_hotplug_workfn(struct work_struct *work)
if (!cpus_updated && top_cpuset.nr_subparts_cpus)
cpus_updated = true;

- /* synchronize cpus_allowed to cpu_active_mask */
+ /* synchronize cpu_active_mask to cpus_allowed */
if (cpus_updated) {
spin_lock_irq(&callback_lock);
if (!on_dfl)
--
2.34.1

2023-06-08 12:33:49

by Waiman Long

Subject: Re: [PATCH] cgroup/cpuset: Fix comment in cpuset_hotplug_workfn

On 6/8/23 04:54, suhua wrote:
> "synchronize cpus_allowed to cpu_active_mask"
> -> "synchronize cpu_active_mask to cpus_allowed"
>
> Signed-off-by: suhua <[email protected]>
> ---
> kernel/cgroup/cpuset.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
> index b0aee733b92b..4810d29e2d63 100644
> --- a/kernel/cgroup/cpuset.c
> +++ b/kernel/cgroup/cpuset.c
> @@ -3739,7 +3739,7 @@ static void cpuset_hotplug_workfn(struct work_struct *work)
> if (!cpus_updated && top_cpuset.nr_subparts_cpus)
> cpus_updated = true;
>
> - /* synchronize cpus_allowed to cpu_active_mask */
> + /* synchronize cpu_active_mask to cpus_allowed */
> if (cpus_updated) {
> spin_lock_irq(&callback_lock);
> if (!on_dfl)

The comment is a bit outdated. The synchronization is only meant for
cgroup v1, but it is correct in this regard. We are matching
cpus_allowed of top_cpuset to cpu_active_mask, not the other way around.

Cheers,
Longman