Commit 63f500c3 authored Mar 22, 2026 by Andrea Righi Committed by Tejun Heo Mar 22, 2026

sched_ext: Guard cpu_smt_mask() with CONFIG_SCHED_SMT



Wrap cpu_smt_mask() usage with CONFIG_SCHED_SMT to avoid build failures
on kernels built without SMT support.

Fixes: 2197cecd ("sched_ext: idle: Prioritize idle SMT sibling")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202603221422.XIueJOE9-lkp@intel.com/


Signed-off-by: Andrea Righi <arighi@nvidia.com>
Reviewed-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

parent e73b1d72

kernel/sched/ext_idle.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -622,6 +622,7 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags,
		goto out_unlock;
		}

		#ifdef CONFIG_SCHED_SMT
		/*
		* Use @prev_cpu's sibling if it's idle.
		*/
		@@ -633,6 +634,7 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags,
		goto out_unlock;
		}
		}
		#endif

		/*
		* Search for any idle CPU in the same LLC domain.