sched_ext: Sync error_irq_work before freeing scx_sched

By the time scx_sched_free_rcu_work() runs, the scx_sched is no longer
reachable. However, a previously queued error_irq_work may still be pending or
running. Ensure it completes before proceeding with teardown.

Fixes: bff3b5aec1b7 ("sched_ext: Move disable machinery into scx_sched")
Acked-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index fc353b8d69f7d736d3081202d7e54166373c1be5..a79dfd0f743a3a9ca6a96c6faa1f4fe0658e8a39 100644 (file)
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -3471,7 +3471,9 @@ static void scx_sched_free_rcu_work(struct work_struct *work)
        struct scx_dispatch_q *dsq;
        int node;
 
+       irq_work_sync(&sch->error_irq_work);
        kthread_stop(sch->helper->task);
+
        free_percpu(sch->pcpu);
 
        for_each_node_state(node, N_POSSIBLE)