[PATCH] sched_ext: use msecs_to_jiffies consistently

From: Julia Lawall
Date: Sun Dec 11 2022 - 17:43:38 EST


The watchdog's timeout is processed by msecs_to_jiffies when it is
checked, but not when the delay for running the watchdog is set. The
watchdog will thus run at a time that is later than that time at which it
is checked that it has run, and the scheduler aborts.

Add the needed calls to msecs_to_jiffies.

Signed-off-by: Julia Lawall <julia.lawall@xxxxxxxx>

---

Another solution would be to use jiffies everywhere.

diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index a28144220501..9d711a70d996 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -1626,6 +1626,7 @@ static bool check_rq_for_timeouts(struct rq *rq)
static void scx_check_timeout_workfn(struct work_struct *work)
{
int cpu;
+ unsigned long timeout;

last_timeout_check = jiffies;
for_each_online_cpu(cpu) {
@@ -1634,8 +1635,8 @@ static void scx_check_timeout_workfn(struct work_struct *work)

cond_resched();
}
- queue_delayed_work(system_unbound_wq, to_delayed_work(work),
- task_runnable_timeout_ms / 2);
+ timeout = msecs_to_jiffies(task_runnable_timeout_ms);
+ queue_delayed_work(system_unbound_wq, to_delayed_work(work), timeout / 2);
}

static void task_tick_scx(struct rq *rq, struct task_struct *curr, int queued)
@@ -2590,6 +2591,7 @@ static int scx_ops_enable(struct sched_ext_ops *ops)
{
struct scx_task_iter sti;
struct task_struct *p;
+ unsigned long timeout;
int i, ret;

mutex_lock(&scx_ops_enable_mutex);
@@ -2674,8 +2676,8 @@ static int scx_ops_enable(struct sched_ext_ops *ops)
}

last_timeout_check = jiffies;
- queue_delayed_work(system_unbound_wq, &check_timeout_work,
- task_runnable_timeout_ms / 2);
+ timeout = msecs_to_jiffies(task_runnable_timeout_ms);
+ queue_delayed_work(system_unbound_wq, &check_timeout_work, timeout / 2);

/*
* Lock out forks, cgroup on/offlining and moves before opening the