5.4-stable review patch. If anyone has any objections, please let me know.
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From: Shrikanth Hegde sshegde@linux.ibm.com
[ Upstream commit 14672f059d83f591afb2ee1fff56858efe055e5a ]
The ftrace selftest reported a failure because writing -1 to sched_rt_runtime_us returns -EBUSY. This happens when the possible CPUs are different from active CPUs.
Active CPUs are part of one root domain, while remaining CPUs are part of def_root_domain. Since active cpumask is being used, this results in cpus=0 when a non active CPUs is used in the loop.
Fix it by looping over the online CPUs instead for validating the bandwidth calculations.
Signed-off-by: Shrikanth Hegde sshegde@linux.ibm.com Signed-off-by: Ingo Molnar mingo@kernel.org Reviewed-by: Juri Lelli juri.lelli@redhat.com Link: https://lore.kernel.org/r/20250306052954.452005-2-sshegde@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/sched/deadline.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index ba3d7c223999e..023d52d2a0f10 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -2513,7 +2513,7 @@ int sched_dl_global_validate(void) * cycling on root_domains... Discussion on different/better * solutions is welcome! */ - for_each_possible_cpu(cpu) { + for_each_online_cpu(cpu) { rcu_read_lock_sched(); dl_b = dl_bw_of(cpu); cpus = dl_bw_cpus(cpu);