# HG changeset patch
# User Dave Plauger <Dave.Plauger@Sun.COM>
# Date 1276784819 14400
# Node ID b4f09d1fd79d010407a83fd03ca614aac431dcb5
# Parent  884a64bb4385d66b3737075a83650a49b8d5c786
6923763 break followed by sync results in panic dump timeout 'dump aborted'

diff -r 884a64bb4385 -r b4f09d1fd79d usr/src/uts/common/os/dumpsubr.c
--- a/usr/src/uts/common/os/dumpsubr.c	Wed Jun 16 22:08:14 2010 -0700
+++ b/usr/src/uts/common/os/dumpsubr.c	Thu Jun 17 10:26:59 2010 -0400
@@ -2098,6 +2098,13 @@
  * panic dump the helper CPUs communicate with the panic CPU using
  * memory variables. All memory mapping and I/O is performed by the
  * panic CPU.
+ *
+ * At dump configuration time, helper_lock is set and helpers_wanted
+ * is 0. dumpsys() decides whether to set helpers_wanted before
+ * clearing helper_lock.
+ *
+ * At panic time, idle CPUs spin-wait on helper_lock, then alternately
+ * take the lock and become a helper, or return.
  */
 void
 dumpsys_helper()
@@ -2122,11 +2129,29 @@
 				return;
 			}
 		}
+
+		/* No more helpers are needed. */
+		dumpcfg.helpers_wanted = 0;
+
 	}
 	dumpsys_spinunlock(&dumpcfg.helper_lock);
 }
 
 /*
+ * No-wait helper callable in spin loops.
+ *
+ * Do not wait for helper_lock. Just check helpers_wanted. The caller
+ * may decide to continue. This is the "c)ontinue, s)ync, r)eset? s"
+ * case.
+ */
+void
+dumpsys_helper_nw()
+{
+	if (dumpcfg.helpers_wanted)
+		dumpsys_helper();
+}
+
+/*
  * Dump helper for live dumps.
  * These run as a system task.
  */
diff -r 884a64bb4385 -r b4f09d1fd79d usr/src/uts/common/sys/dumphdr.h
--- a/usr/src/uts/common/sys/dumphdr.h	Wed Jun 16 22:08:14 2010 -0700
+++ b/usr/src/uts/common/sys/dumphdr.h	Thu Jun 17 10:26:59 2010 -0400
@@ -19,8 +19,7 @@
  * CDDL HEADER END
  */
 /*
- * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
- * Use is subject to license terms.
+ * Copyright (c) 1998, 2010, Oracle and/or its affiliates. All rights reserved.
  */
 
 #ifndef _SYS_DUMPHDR_H
@@ -183,6 +182,7 @@
 extern void dump_addpage(struct as *, void *, pfn_t);
 extern void dumpsys(void);
 extern void dumpsys_helper(void);
+extern void dumpsys_helper_nw(void);
 extern void dump_messages(void);
 extern void dump_ereports(void);
 extern void dumpvp_write(const void *, size_t);
diff -r 884a64bb4385 -r b4f09d1fd79d usr/src/uts/sun4/os/mp_states.c
--- a/usr/src/uts/sun4/os/mp_states.c	Wed Jun 16 22:08:14 2010 -0700
+++ b/usr/src/uts/sun4/os/mp_states.c	Thu Jun 17 10:26:59 2010 -0400
@@ -2,9 +2,8 @@
  * CDDL HEADER START
  *
  * The contents of this file are subject to the terms of the
- * Common Development and Distribution License, Version 1.0 only
- * (the "License").  You may not use this file except in compliance
- * with the License.
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
  *
  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  * or http://www.opensolaris.org/os/licensing.
@@ -20,12 +19,9 @@
  * CDDL HEADER END
  */
 /*
- * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
- * Use is subject to license terms.
+ * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
  */
 
-#pragma ident	"%Z%%M%	%I%	%E% SMI"
-
 #include <sys/systm.h>
 #include <sys/membar.h>
 #include <sys/machsystm.h>
@@ -34,6 +30,7 @@
 #include <sys/cpuvar.h>
 #include <sys/cpu_module.h>
 #include <sys/cmp.h>
+#include <sys/dumphdr.h>
 
 #include <sys/cpu_sgnblk_defs.h>
 
@@ -75,7 +72,7 @@
 
 	kern_idle[CPU->cpu_id] = 1;
 	while (kern_idle[CPU->cpu_id])
-		/* SPIN */;
+		dumpsys_helper_nw();
 
 	CPU->cpu_m.in_prom = 0;
 	membar_stld();