On 7/25/24 7:25 AM, Chen Ridong wrote:
> There are several functions to decrease attach_in_progress, and they
> will wake up cpuset_attach_wq when attach_in_progress is zero. So,
> add a helper to make it concise.
>
> Signed-off-by: Chen Ridong <chenridong@xxxxxxxxxx>
> ---
> kernel/cgroup/cpuset.c | 28 +++++++++++++++-------------
> 1 file changed, 15 insertions(+), 13 deletions(-)
>
> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
> index d4322619e59a..c241845694ac 100644
> --- a/kernel/cgroup/cpuset.c
> +++ b/kernel/cgroup/cpuset.c
> @@ -490,6 +490,17 @@ static inline void check_insane_mems_config(nodemask_t *nodes)
> }
> }
>
> +/*
> + * decrease cs->attach_in_progress.
> + * wake_up cpuset_attach_wq if cs->attach_in_progress==0.
In the description, adding locking constraint of cpuset_mutex would be helpful.
Something like "cpuset_mutex must be held by the caller."
> + */
> +static inline void dec_attach_in_progress(struct cpuset *cs)
> +{
> + cs->attach_in_progress--;
> + if (!cs->attach_in_progress)
> + wake_up(&cpuset_attach_wq);
> +}
> +
> /*
> * Cgroup v2 behavior is used on the "cpus" and "mems" control files when
> * on default hierarchy or when the cpuset_v2_mode flag is set by mounting
> @@ -3421,9 +3432,7 @@ static void cpuset_cancel_attach(struct cgroup_taskset *tset)
> cs = css_cs(css);
>
> mutex_lock(&cpuset_mutex);
> - cs->attach_in_progress--;
> - if (!cs->attach_in_progress)
> - wake_up(&cpuset_attach_wq);
> + dec_attach_in_progress(cs);
>
> if (cs->nr_migrate_dl_tasks) {
> int cpu = cpumask_any(cs->effective_cpus);
> @@ -3538,9 +3547,7 @@ static void cpuset_attach(struct cgroup_taskset *tset)
> reset_migrate_dl_data(cs);
> }
>
> - cs->attach_in_progress--;
> - if (!cs->attach_in_progress)
> - wake_up(&cpuset_attach_wq);
> + dec_attach_in_progress(cs);
>
> mutex_unlock(&cpuset_mutex);
> }
> @@ -4284,9 +4291,7 @@ static void cpuset_cancel_fork(struct task_struct *task, struct css_set *cset)
> return;
>
> mutex_lock(&cpuset_mutex);
> - cs->attach_in_progress--;
> - if (!cs->attach_in_progress)
> - wake_up(&cpuset_attach_wq);
> + dec_attach_in_progress(cs);
> mutex_unlock(&cpuset_mutex);
> }
>
> @@ -4319,10 +4324,7 @@ static void cpuset_fork(struct task_struct *task)
> guarantee_online_mems(cs, &cpuset_attach_nodemask_to);
> cpuset_attach_task(cs, task);
>
> - cs->attach_in_progress--;
> - if (!cs->attach_in_progress)
> - wake_up(&cpuset_attach_wq);
> -
> + dec_attach_in_progress(cs);
> mutex_unlock(&cpuset_mutex);
> }
>
--
Thanks,
Kamalesh
