scx: Add maintainer and maintainer url to struct_ops

If the loaded BPF scheduler encounters an error finding the appropriate
support will be challenging. Add fields to the struct_ops for sched_ext
to include a scheduler maintainer and an optional support url.

Signed-off-by: Daniel Hodges <hodges.daniel.scott@gmail.com>

include/linux/sched/ext.h

@@ -16,6 +16,8 @@
 
 enum scx_public_consts {
 	SCX_OPS_NAME_LEN	= 128,
+	SCX_MAINTAINER_LEN	= 128,
+	SCX_MAINTAINER_URL_LEN	= 128,
 
 	SCX_SLICE_DFL		= 20 * 1000000,	/* 20ms */
 	SCX_SLICE_INF		= U64_MAX,	/* infinite, implies nohz */

kernel/sched/ext.c

@@ -669,6 +669,22 @@ struct sched_ext_ops {
 	 * BPF scheduler is enabled.
 	 */
 	char name[SCX_OPS_NAME_LEN];
+
+	/**
+	 * maintainer - Maintainer of the BPF scheduler
+	 *
+	 * If the BPF scheduler encounters an error the maintainer will be
+	 * included in the error message as the support contact.
+	 */
+	char maintainer[SCX_MAINTAINER_LEN];
+
+	/**
+	 * maintainer_url - URL for scheduler related issues
+	 *
+	 * URL of the maintainer for support of the BPF scheduler. The support
+	 * URL be included in error messages with the maintainer.
+	 */
+	char maintainer_url[SCX_MAINTAINER_URL_LEN];
 };
 
 enum scx_opi {
@@ -4453,6 +4469,14 @@ static void scx_ops_disable_workfn(struct kthread_work *work)
 			printk(KERN_ERR "sched_ext: %s\n", ei->reason);
 		else
 			printk(KERN_ERR "sched_ext: %s (%s)\n", ei->reason, ei->msg);
+		if (strlen(scx_ops.maintainer))
+			printk(KERN_ERR,
+				"sched_ext: BPF scheduler maintainer: %s\n",
+			       	scx_ops.maintainer);
+		if (strlen(scx_ops.maintainer_url))
+			printk(KERN_ERR,
+				"sched_ext: BPF scheduler support url: %s\n",
+			       	scx_ops.maintainer_url);
 
 		stack_trace_print(ei->bt, ei->bt_len, 2);
 	}