sched_ext: Record an error on errno-only sub-enable failure

scx_sub_enable_workfn() has several failure paths that only return an errno (e.g. -ENOMEM from an allocation) and jump to err_disable without calling scx_error(). scx_flush_disable_work() runs the disable, and thus ops.exit(), only when an error has been recorded, so an errno-only failure leaves the half-initialized sub-scheduler linked. Record an error at the err_disable sink so every errno-only failure runs the disable path.

Tejun Heo committed 4 months ago

Commit db4e9de1 parent cfe950d1 file · +6 −0Browse files

Unified · Split

kernel/sched/ext/ext.c+6−0

@@ -7746,6 +7746,12 @@ err_unlock_and_disable: · 7745 unmodified lines
7746	7746	percpu_up_write(&scx_fork_rwsem);
7747	7747	err_disable:
7748	7748	mutex_unlock(&scx_enable_mutex);
	7749	+ /*
	7750	+ * Some enable failures only return an errno (e.g. -ENOMEM from an
	7751	+ * allocation) without calling scx_error(). Record it so
	7752	+ * scx_flush_disable_work() runs the disable and ops.exit() fires.
	7753	+ */
	7754	+ scx_error(sch, "scx_sub_enable() failed (%d)", ret);
7749	7755	scx_flush_disable_work(sch);
7750	7756	cmd->ret = 0;
7751	7757	}