Wed Feb 28 04:14:47 2024 UTC (97d)
heartbeat(9): Restore still-applicable comment nixed in last commit.

The nesting depth is stored in ci_heartbeat_suspend which is 32-bit.


(riastradh)
diff -r1.11 -r1.12 src/sys/kern/kern_heartbeat.c
cvs diff -r1.11 -r1.12 src/sys/kern/kern_heartbeat.c (expand / switch to unified diff)

--- src/sys/kern/kern_heartbeat.c 2024/02/28 04:12:59 1.11
+++ src/sys/kern/kern_heartbeat.c 2024/02/28 04:14:47 1.12
@@ -1,14 +1,14 @@ @@ -1,14 +1,14 @@
1/* $NetBSD: kern_heartbeat.c,v 1.11 2024/02/28 04:12:59 riastradh Exp $ */ 1/* $NetBSD: kern_heartbeat.c,v 1.12 2024/02/28 04:14:47 riastradh Exp $ */
2 2
3/*- 3/*-
4 * Copyright (c) 2023 The NetBSD Foundation, Inc. 4 * Copyright (c) 2023 The NetBSD Foundation, Inc.
5 * All rights reserved. 5 * All rights reserved.
6 * 6 *
7 * Redistribution and use in source and binary forms, with or without 7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions 8 * modification, are permitted provided that the following conditions
9 * are met: 9 * are met:
10 * 1. Redistributions of source code must retain the above copyright 10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer. 11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright 12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the 13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution. 14 * documentation and/or other materials provided with the distribution.
@@ -72,27 +72,27 @@ @@ -72,27 +72,27 @@
72 * sysctl -w debug.crashme.spl_spinout=5 # IPL_VM 72 * sysctl -w debug.crashme.spl_spinout=5 # IPL_VM
73 * # verify system panics after 15sec, with a stack trace through 73 * # verify system panics after 15sec, with a stack trace through
74 * # crashme_spl_spinout 74 * # crashme_spl_spinout
75 * 75 *
76 * # Not this -- IPL_SCHED and IPL_HIGH spinout on a single CPU 76 * # Not this -- IPL_SCHED and IPL_HIGH spinout on a single CPU
77 * # require a hardware watchdog timer. 77 * # require a hardware watchdog timer.
78 * #cpuctl offline 0 78 * #cpuctl offline 0
79 * #sysctl -w debug.crashme_enable 79 * #sysctl -w debug.crashme_enable
80 * #sysctl -w debug.crashme.spl_spinout=6 # IPL_SCHED 80 * #sysctl -w debug.crashme.spl_spinout=6 # IPL_SCHED
81 * # hope watchdog timer kicks in 81 * # hope watchdog timer kicks in
82 */ 82 */
83 83
84#include <sys/cdefs.h> 84#include <sys/cdefs.h>
85__KERNEL_RCSID(0, "$NetBSD: kern_heartbeat.c,v 1.11 2024/02/28 04:12:59 riastradh Exp $"); 85__KERNEL_RCSID(0, "$NetBSD: kern_heartbeat.c,v 1.12 2024/02/28 04:14:47 riastradh Exp $");
86 86
87#ifdef _KERNEL_OPT 87#ifdef _KERNEL_OPT
88#include "opt_ddb.h" 88#include "opt_ddb.h"
89#include "opt_heartbeat.h" 89#include "opt_heartbeat.h"
90#endif 90#endif
91 91
92#include "heartbeat.h" 92#include "heartbeat.h"
93 93
94#include <sys/param.h> 94#include <sys/param.h>
95#include <sys/types.h> 95#include <sys/types.h>
96 96
97#include <sys/atomic.h> 97#include <sys/atomic.h>
98#include <sys/cpu.h> 98#include <sys/cpu.h>
@@ -122,28 +122,28 @@ __KERNEL_RCSID(0, "$NetBSD: kern_heartbe @@ -122,28 +122,28 @@ __KERNEL_RCSID(0, "$NetBSD: kern_heartbe
122kmutex_t heartbeat_lock __cacheline_aligned; 122kmutex_t heartbeat_lock __cacheline_aligned;
123unsigned heartbeat_max_period_secs __read_mostly; 123unsigned heartbeat_max_period_secs __read_mostly;
124unsigned heartbeat_max_period_ticks __read_mostly; 124unsigned heartbeat_max_period_ticks __read_mostly;
125 125
126void *heartbeat_sih __read_mostly; 126void *heartbeat_sih __read_mostly;
127 127
128/* 128/*
129 * heartbeat_suspend() 129 * heartbeat_suspend()
130 * 130 *
131 * Suspend heartbeat monitoring of the current CPU. 131 * Suspend heartbeat monitoring of the current CPU.
132 * 132 *
133 * Called after the current CPU has been marked offline but before 133 * Called after the current CPU has been marked offline but before
134 * it has stopped running, or after IPL has been raised for 134 * it has stopped running, or after IPL has been raised for
135 * polling-mode console input. Nestable. Reversed by 135 * polling-mode console input. Nestable (but only 2^32 times, so
136 * heartbeat_resume. 136 * don't do this in a loop). Reversed by heartbeat_resume.
137 * 137 *
138 * Caller must be bound to the CPU, i.e., curcpu_stable() must be 138 * Caller must be bound to the CPU, i.e., curcpu_stable() must be
139 * true. This function does not assert curcpu_stable() since it 139 * true. This function does not assert curcpu_stable() since it
140 * is used in the ddb entry path, where any assertions risk 140 * is used in the ddb entry path, where any assertions risk
141 * infinite regress into undebuggable chaos, so callers must be 141 * infinite regress into undebuggable chaos, so callers must be
142 * careful. 142 * careful.
143 */ 143 */
144void 144void
145heartbeat_suspend(void) 145heartbeat_suspend(void)
146{ 146{
147 unsigned *p; 147 unsigned *p;
148 148
149 p = &curcpu()->ci_heartbeat_suspend; 149 p = &curcpu()->ci_heartbeat_suspend;