Hi, On 29/10/25 20:08, Andrea Righi wrote: > From: Joel Fernandes <[email protected]> > > 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. > > Acked-by: Tejun Heo <[email protected]> > Reviewed-by: Juri Lelli <[email protected]> > Reviewed-by: Andrea Righi <[email protected]> > Signed-off-by: Joel Fernandes <[email protected]> > --- > 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 6cf9be6eea49a..e71f6618c1a6a 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) > dl_server_start(&rq->fair_server);
Something that I noticed while reviewing this series is that we still start back a server even if the user put its runtime to zero (disabling it) and I don't think we want to do that. It's not of course related to this change or this series per-se, but something we probably want to fix independently. Thanks, Juri
