[PATCH RFC 5/8] sched/debug: Stop and start server based on if it was active
From: Joel Fernandes
Date: Fri Mar 14 2025 - 22:23:16 EST
Currently the DL server interface for applying parameters checkfs
CFS-internals to identify if the server is active. This is error-prone
and make it difficult when adding new servers in the future.
Fix it, by using dl_server_active() which is also used by the DL server
code to determine if the DL server was started.
Reviewed-by: Andrea Righi <arighi@xxxxxxxxxx>
Signed-off-by: Joel Fernandes <joelagnelf@xxxxxxxxxx>
---
kernel/sched/debug.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 1ccc7687e1a8..83cb695d6d46 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -347,6 +347,7 @@ static ssize_t sched_fair_server_write(struct file *filp, const char __user *ubu
{
long cpu = (long) ((struct seq_file *) filp->private_data)->private;
struct rq *rq = cpu_rq(cpu);
+ bool was_active = false;
u64 runtime, period;
int retval = 0;
size_t err;
@@ -379,7 +380,8 @@ static ssize_t sched_fair_server_write(struct file *filp, const char __user *ubu
return -EINVAL;
}
- if (rq->cfs.h_nr_queued) {
+ if (dl_server_active(&rq->fair_server)) {
+ was_active = true;
update_rq_clock(rq);
dl_server_stop(&rq->fair_server);
}
@@ -390,7 +392,7 @@ static ssize_t sched_fair_server_write(struct file *filp, const char __user *ubu
printk_deferred("Fair server disabled in CPU %d, system may crash due to starvation.\n",
cpu_of(rq));
- if (rq->cfs.h_nr_queued)
+ if (was_active)
dl_server_start(&rq->fair_server);
if (retval < 0)
--
2.43.0