diff options
| author | Cheng-Yang Chou <yphbchou0911@gmail.com> | 2026-03-21 18:54:58 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-04-11 14:29:40 +0200 |
| commit | fdc7a8fbd3d701cb25df4db37d8dba6e887dbf05 (patch) | |
| tree | 7529838f5ddc065eeee36a92081fba68f64d962e | |
| parent | 2d4a6f0702c5211e0be8b688c5fc24f082ec74d6 (diff) | |
sched_ext: Fix inconsistent NUMA node lookup in scx_select_cpu_dfl()
commit db08b1940f4beb25460b4a4e9da3446454f2e8fe upstream.
In the WAKE_SYNC path of scx_select_cpu_dfl(), waker_node was computed
with cpu_to_node(), while node (for prev_cpu) was computed with
scx_cpu_node_if_enabled(). When scx_builtin_idle_per_node is disabled,
idle_cpumask(waker_node) is called with a real node ID even though
per-node idle tracking is disabled, resulting in undefined behavior.
Fix by using scx_cpu_node_if_enabled() for waker_node as well, ensuring
both variables are computed consistently.
Fixes: 48849271e6611 ("sched_ext: idle: Per-node idle cpumasks")
Cc: stable@vger.kernel.org # v6.15+
Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/sched/ext_idle.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/sched/ext_idle.c b/kernel/sched/ext_idle.c index 3d9d404d5cd2..e11486c60e5a 100644 --- a/kernel/sched/ext_idle.c +++ b/kernel/sched/ext_idle.c @@ -543,7 +543,7 @@ s32 scx_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags, * piled up on it even if there is an idle core elsewhere on * the system. */ - waker_node = cpu_to_node(cpu); + waker_node = scx_cpu_node_if_enabled(cpu); if (!(current->flags & PF_EXITING) && cpu_rq(cpu)->scx.local_dsq.nr == 0 && (!(flags & SCX_PICK_IDLE_IN_NODE) || (waker_node == node)) && |