Module Name: src
Committed By: riastradh
Date: Sat Sep 2 17:44:12 UTC 2023
Modified Files:
src/sys/dev: cons.c
Log Message:
cons(9): Suspend heartbeat checks while in polled-input mode.
This goes into a tight loop at high IPL, so it is to be expected that
the heartbeats will stop happening.
Should fix heartbeat panics at root device prompt on boot.
To generate a diff of this commit:
cvs rdiff -u -r1.93 -r1.94 src/sys/dev/cons.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/cons.c
diff -u src/sys/dev/cons.c:1.93 src/sys/dev/cons.c:1.94
--- src/sys/dev/cons.c:1.93 Sat Sep 2 17:43:46 2023
+++ src/sys/dev/cons.c Sat Sep 2 17:44:12 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: cons.c,v 1.93 2023/09/02 17:43:46 riastradh Exp $ */
+/* $NetBSD: cons.c,v 1.94 2023/09/02 17:44:12 riastradh Exp $ */
/*
* Copyright (c) 1988 University of Utah.
@@ -39,7 +39,11 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: cons.c,v 1.93 2023/09/02 17:43:46 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: cons.c,v 1.94 2023/09/02 17:44:12 riastradh Exp $");
+
+#ifdef _KERNEL_OPT
+#include "opt_heartbeat.h"
+#endif
#include <sys/param.h>
@@ -47,6 +51,7 @@ __KERNEL_RCSID(0, "$NetBSD: cons.c,v 1.9
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/file.h>
+#include <sys/heartbeat.h>
#include <sys/ioctl.h>
#include <sys/kauth.h>
#include <sys/module.h>
@@ -417,8 +422,30 @@ cnpollc(int on)
return;
if (!on)
--refcount;
- if (refcount == 0)
+ if (refcount == 0) {
+#ifdef HEARTBEAT
+ if (on) {
+ /*
+ * Bind to the current CPU by disabling
+ * preemption (more convenient than finding a
+ * place to store a stack to unwind for
+ * curlwp_bind/bindx, and preemption wouldn't
+ * happen anyway while spinning at high IPL in
+ * cngetc) so that curcpu() is stable so that
+ * we can suspend heartbeat checks for it.
+ */
+ kpreempt_disable();
+ heartbeat_suspend();
+ }
+#endif
(*cn_tab->cn_pollc)(cn_tab->cn_dev, on);
+#ifdef HEARTBEAT
+ if (!on) {
+ heartbeat_resume();
+ kpreempt_enable();
+ }
+#endif
+ }
if (on)
++refcount;
}
