From: Joel Fernandes joelagnelf@nvidia.com
Currently the DL server interface for applying parameters checks CFS-internals to identify if the server is active. This is error-prone and makes 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.
v2: do not start the server if runtime is zero (Juri Lelli)
Tested-by: Christian Loehle christian.loehle@arm.com Acked-by: Tejun Heo tj@kernel.org Reviewed-by: Juri Lelli juri.lelli@redhat.com Reviewed-by: Andrea Righi arighi@nvidia.com Signed-off-by: Joel Fernandes joelagnelf@nvidia.com --- kernel/sched/debug.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index 93f009e1076d8..dd793f8f3858a 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -354,6 +354,8 @@ static ssize_t sched_fair_server_write(struct file *filp, const char __user *ubu return err;
scoped_guard (rq_lock_irqsave, rq) { + bool is_active; + runtime = rq->fair_server.dl_runtime; period = rq->fair_server.dl_period;
@@ -376,8 +378,11 @@ static ssize_t sched_fair_server_write(struct file *filp, const char __user *ubu return -EINVAL; }
- update_rq_clock(rq); - dl_server_stop(&rq->fair_server); + is_active = dl_server_active(&rq->fair_server); + if (is_active) { + update_rq_clock(rq); + dl_server_stop(&rq->fair_server); + }
retval = dl_server_apply_params(&rq->fair_server, runtime, period, 0);
@@ -385,7 +390,7 @@ 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 (is_active && runtime) dl_server_start(&rq->fair_server);
if (retval < 0)