blob: 6d78841fd41677d4f81dbcb53eed7ab8602cddb4 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001Documentation for /proc/sys/kernel/* kernel version 2.2.10
2 (c) 1998, 1999, Rik van Riel <riel@nl.linux.org>
Shen Feng760df932009-04-02 16:57:20 -07003 (c) 2009, Shen Feng<shen@cn.fujitsu.com>
Linus Torvalds1da177e2005-04-16 15:20:36 -07004
5For general info and legal blurb, please look in README.
6
7==============================================================
8
9This file contains documentation for the sysctl files in
10/proc/sys/kernel/ and is valid for Linux kernel version 2.2.
11
12The files in this directory can be used to tune and monitor
13miscellaneous and general things in the operation of the Linux
14kernel. Since some of the files _can_ be used to screw up your
15system, it is advisable to read both documentation and source
16before actually making adjustments.
17
18Currently, these files might (depending on your configuration)
19show up in /proc/sys/kernel:
Borislav Petkov807094c2011-07-23 10:39:29 -070020
Linus Torvalds1da177e2005-04-16 15:20:36 -070021- acct
Borislav Petkov807094c2011-07-23 10:39:29 -070022- acpi_video_flags
23- auto_msgmni
H. Peter Anvind75757a2009-12-11 14:23:44 -080024- bootloader_type [ X86 only ]
25- bootloader_version [ X86 only ]
Hans-Joachim Pichtc114728a2009-09-11 10:28:47 +020026- callhome [ S390 only ]
Dan Ballard73efc032011-10-31 17:11:20 -070027- cap_last_cap
Linus Torvalds1da177e2005-04-16 15:20:36 -070028- core_pattern
Neil Hormana2939802009-09-23 15:56:56 -070029- core_pipe_limit
Linus Torvalds1da177e2005-04-16 15:20:36 -070030- core_uses_pid
31- ctrl-alt-del
Dan Rosenbergeaf06b22010-11-11 14:05:18 -080032- dmesg_restrict
Linus Torvalds1da177e2005-04-16 15:20:36 -070033- domainname
34- hostname
35- hotplug
Dan Rosenberg455cd5a2011-01-12 16:59:41 -080036- kptr_restrict
Chuck Ebbert0741f4d2006-12-07 02:14:11 +010037- kstack_depth_to_print [ X86 only ]
Linus Torvalds1da177e2005-04-16 15:20:36 -070038- l2cr [ PPC only ]
Michael Opdenackerac76cff2008-02-13 15:03:32 -080039- modprobe ==> Documentation/debugging-modules.txt
Kees Cook3d433212009-04-02 15:49:29 -070040- modules_disabled
Linus Torvalds1da177e2005-04-16 15:20:36 -070041- msgmax
42- msgmnb
43- msgmni
Shen Feng760df932009-04-02 16:57:20 -070044- nmi_watchdog
Linus Torvalds1da177e2005-04-16 15:20:36 -070045- osrelease
46- ostype
47- overflowgid
48- overflowuid
49- panic
Borislav Petkov807094c2011-07-23 10:39:29 -070050- panic_on_oops
51- panic_on_unrecovered_nmi
Mitsuo Hayasaka55af7792011-11-29 15:08:36 +090052- panic_on_stackoverflow
Linus Torvalds1da177e2005-04-16 15:20:36 -070053- pid_max
54- powersave-nap [ PPC only ]
55- printk
Borislav Petkov807094c2011-07-23 10:39:29 -070056- printk_delay
57- printk_ratelimit
58- printk_ratelimit_burst
Jiri Kosina1ec7fd52008-02-09 23:24:08 +010059- randomize_va_space
Linus Torvalds1da177e2005-04-16 15:20:36 -070060- real-root-dev ==> Documentation/initrd.txt
61- reboot-cmd [ SPARC only ]
62- rtsig-max
63- rtsig-nr
64- sem
65- sg-big-buff [ generic SCSI device (sg) ]
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -070066- shm_rmid_forced
Linus Torvalds1da177e2005-04-16 15:20:36 -070067- shmall
68- shmmax [ sysv ipc ]
69- shmmni
Borislav Petkov807094c2011-07-23 10:39:29 -070070- softlockup_thresh
Linus Torvalds1da177e2005-04-16 15:20:36 -070071- stop-a [ SPARC only ]
72- sysrq ==> Documentation/sysrq.txt
73- tainted
74- threads-max
Shen Feng760df932009-04-02 16:57:20 -070075- unknown_nmi_panic
Linus Torvalds1da177e2005-04-16 15:20:36 -070076- version
77
78==============================================================
79
80acct:
81
82highwater lowwater frequency
83
84If BSD-style process accounting is enabled these values control
85its behaviour. If free space on filesystem where the log lives
86goes below <lowwater>% accounting suspends. If free space gets
87above <highwater>% accounting resumes. <Frequency> determines
88how often do we check the amount of free space (value is in
89seconds). Default:
904 2 30
91That is, suspend accounting if there left <= 2% free; resume it
92if we got >=4%; consider information about amount of free space
93valid for 30 seconds.
94
95==============================================================
96
Borislav Petkov807094c2011-07-23 10:39:29 -070097acpi_video_flags:
98
99flags
100
101See Doc*/kernel/power/video.txt, it allows mode of video boot to be
102set during run time.
103
104==============================================================
105
106auto_msgmni:
107
108Enables/Disables automatic recomputing of msgmni upon memory add/remove
109or upon ipc namespace creation/removal (see the msgmni description
110above). Echoing "1" into this file enables msgmni automatic recomputing.
111Echoing "0" turns it off. auto_msgmni default value is 1.
112
113
114==============================================================
115
H. Peter Anvind75757a2009-12-11 14:23:44 -0800116bootloader_type:
117
118x86 bootloader identification
119
120This gives the bootloader type number as indicated by the bootloader,
121shifted left by 4, and OR'd with the low four bits of the bootloader
122version. The reason for this encoding is that this used to match the
123type_of_loader field in the kernel header; the encoding is kept for
124backwards compatibility. That is, if the full bootloader type number
125is 0x15 and the full version number is 0x234, this file will contain
126the value 340 = 0x154.
127
128See the type_of_loader and ext_loader_type fields in
129Documentation/x86/boot.txt for additional information.
130
131==============================================================
132
133bootloader_version:
134
135x86 bootloader version
136
137The complete bootloader version number. In the example above, this
138file will contain the value 564 = 0x234.
139
140See the type_of_loader and ext_loader_ver fields in
141Documentation/x86/boot.txt for additional information.
142
143==============================================================
144
Hans-Joachim Pichtc114728a2009-09-11 10:28:47 +0200145callhome:
146
147Controls the kernel's callhome behavior in case of a kernel panic.
148
149The s390 hardware allows an operating system to send a notification
150to a service organization (callhome) in case of an operating system panic.
151
152When the value in this file is 0 (which is the default behavior)
153nothing happens in case of a kernel panic. If this value is set to "1"
154the complete kernel oops message is send to the IBM customer service
155organization in case the mainframe the Linux operating system is running
156on has a service contract with IBM.
157
158==============================================================
159
Dan Ballard73efc032011-10-31 17:11:20 -0700160cap_last_cap
161
162Highest valid capability of the running kernel. Exports
163CAP_LAST_CAP from the kernel.
164
165==============================================================
166
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167core_pattern:
168
169core_pattern is used to specify a core dumpfile pattern name.
Matthias Urlichscd081042006-10-11 01:21:57 -0700170. max length 128 characters; default value is "core"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171. core_pattern is used as a pattern template for the output filename;
172 certain string patterns (beginning with '%') are substituted with
173 their actual values.
174. backward compatibility with core_uses_pid:
175 If core_pattern does not include "%p" (default does not)
176 and core_uses_pid is set, then .PID will be appended to
177 the filename.
178. corename format specifiers:
179 %<NUL> '%' is dropped
180 %% output one '%'
181 %p pid
182 %u uid
183 %g gid
184 %s signal number
185 %t UNIX time of dump
186 %h hostname
Jiri Slaby57cc0832011-05-26 16:25:46 -0700187 %e executable filename (may be shortened)
188 %E executable path
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 %<OTHER> both are dropped
Matthias Urlichscd081042006-10-11 01:21:57 -0700190. If the first character of the pattern is a '|', the kernel will treat
191 the rest of the pattern as a command to run. The core dump will be
192 written to the standard input of that program instead of to a file.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193
194==============================================================
195
Neil Hormana2939802009-09-23 15:56:56 -0700196core_pipe_limit:
197
Borislav Petkov807094c2011-07-23 10:39:29 -0700198This sysctl is only applicable when core_pattern is configured to pipe
199core files to a user space helper (when the first character of
200core_pattern is a '|', see above). When collecting cores via a pipe
201to an application, it is occasionally useful for the collecting
202application to gather data about the crashing process from its
203/proc/pid directory. In order to do this safely, the kernel must wait
204for the collecting process to exit, so as not to remove the crashing
205processes proc files prematurely. This in turn creates the
206possibility that a misbehaving userspace collecting process can block
207the reaping of a crashed process simply by never exiting. This sysctl
208defends against that. It defines how many concurrent crashing
209processes may be piped to user space applications in parallel. If
210this value is exceeded, then those crashing processes above that value
211are noted via the kernel log and their cores are skipped. 0 is a
212special value, indicating that unlimited processes may be captured in
213parallel, but that no waiting will take place (i.e. the collecting
214process is not guaranteed access to /proc/<crashing pid>/). This
215value defaults to 0.
Neil Hormana2939802009-09-23 15:56:56 -0700216
217==============================================================
218
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219core_uses_pid:
220
221The default coredump filename is "core". By setting
222core_uses_pid to 1, the coredump filename becomes core.PID.
223If core_pattern does not include "%p" (default does not)
224and core_uses_pid is set, then .PID will be appended to
225the filename.
226
227==============================================================
228
229ctrl-alt-del:
230
231When the value in this file is 0, ctrl-alt-del is trapped and
232sent to the init(1) program to handle a graceful restart.
233When, however, the value is > 0, Linux's reaction to a Vulcan
234Nerve Pinch (tm) will be an immediate reboot, without even
235syncing its dirty buffers.
236
237Note: when a program (like dosemu) has the keyboard in 'raw'
238mode, the ctrl-alt-del is intercepted by the program before it
239ever reaches the kernel tty layer, and it's up to the program
240to decide what to do with it.
241
242==============================================================
243
Dan Rosenbergeaf06b22010-11-11 14:05:18 -0800244dmesg_restrict:
245
Borislav Petkov807094c2011-07-23 10:39:29 -0700246This toggle indicates whether unprivileged users are prevented
247from using dmesg(8) to view messages from the kernel's log buffer.
248When dmesg_restrict is set to (0) there are no restrictions. When
Serge E. Hallyn38ef4c22010-12-08 15:19:01 +0000249dmesg_restrict is set set to (1), users must have CAP_SYSLOG to use
Dan Rosenbergeaf06b22010-11-11 14:05:18 -0800250dmesg(8).
251
Borislav Petkov807094c2011-07-23 10:39:29 -0700252The kernel config option CONFIG_SECURITY_DMESG_RESTRICT sets the
253default value of dmesg_restrict.
Dan Rosenbergeaf06b22010-11-11 14:05:18 -0800254
255==============================================================
256
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257domainname & hostname:
258
259These files can be used to set the NIS/YP domainname and the
260hostname of your box in exactly the same way as the commands
261domainname and hostname, i.e.:
262# echo "darkstar" > /proc/sys/kernel/hostname
263# echo "mydomain" > /proc/sys/kernel/domainname
264has the same effect as
265# hostname "darkstar"
266# domainname "mydomain"
267
268Note, however, that the classic darkstar.frop.org has the
269hostname "darkstar" and DNS (Internet Domain Name Server)
270domainname "frop.org", not to be confused with the NIS (Network
271Information Service) or YP (Yellow Pages) domainname. These two
272domain names are in general different. For a detailed discussion
273see the hostname(1) man page.
274
275==============================================================
276
277hotplug:
278
279Path for the hotplug policy agent.
280Default value is "/sbin/hotplug".
281
282==============================================================
283
Dan Rosenberg455cd5a2011-01-12 16:59:41 -0800284kptr_restrict:
285
286This toggle indicates whether restrictions are placed on
287exposing kernel addresses via /proc and other interfaces. When
288kptr_restrict is set to (0), there are no restrictions. When
289kptr_restrict is set to (1), the default, kernel pointers
290printed using the %pK format specifier will be replaced with 0's
291unless the user has CAP_SYSLOG. When kptr_restrict is set to
292(2), kernel pointers printed using %pK will be replaced with 0's
293regardless of privileges.
294
295==============================================================
296
Chuck Ebbert0741f4d2006-12-07 02:14:11 +0100297kstack_depth_to_print: (X86 only)
298
299Controls the number of words to print when dumping the raw
300kernel stack.
301
302==============================================================
303
Borislav Petkov807094c2011-07-23 10:39:29 -0700304l2cr: (PPC only)
305
306This flag controls the L2 cache of G3 processor boards. If
3070, the cache is disabled. Enabled if nonzero.
308
309==============================================================
310
Kees Cook3d433212009-04-02 15:49:29 -0700311modules_disabled:
312
313A toggle value indicating if modules are allowed to be loaded
314in an otherwise modular kernel. This toggle defaults to off
315(0), but can be set true (1). Once true, modules can be
316neither loaded nor unloaded, and the toggle cannot be set back
317to false.
318
319==============================================================
320
Borislav Petkov807094c2011-07-23 10:39:29 -0700321nmi_watchdog:
322
323Enables/Disables the NMI watchdog on x86 systems. When the value is
324non-zero the NMI watchdog is enabled and will continuously test all
325online cpus to determine whether or not they are still functioning
326properly. Currently, passing "nmi_watchdog=" parameter at boot time is
327required for this function to work.
328
329If LAPIC NMI watchdog method is in use (nmi_watchdog=2 kernel
330parameter), the NMI watchdog shares registers with oprofile. By
331disabling the NMI watchdog, oprofile may have more registers to
332utilize.
333
334==============================================================
335
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336osrelease, ostype & version:
337
338# cat osrelease
3392.1.88
340# cat ostype
341Linux
342# cat version
343#5 Wed Feb 25 21:49:24 MET 1998
344
345The files osrelease and ostype should be clear enough. Version
346needs a little more clarification however. The '#5' means that
347this is the fifth kernel built from this source base and the
348date behind it indicates the time the kernel was built.
349The only way to tune these values is to rebuild the kernel :-)
350
351==============================================================
352
353overflowgid & overflowuid:
354
Borislav Petkov807094c2011-07-23 10:39:29 -0700355if your architecture did not always support 32-bit UIDs (i.e. arm,
356i386, m68k, sh, and sparc32), a fixed UID and GID will be returned to
357applications that use the old 16-bit UID/GID system calls, if the
358actual UID or GID would exceed 65535.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359
360These sysctls allow you to change the value of the fixed UID and GID.
361The default is 65534.
362
363==============================================================
364
365panic:
366
Borislav Petkov807094c2011-07-23 10:39:29 -0700367The value in this file represents the number of seconds the kernel
368waits before rebooting on a panic. When you use the software watchdog,
369the recommended setting is 60.
370
371==============================================================
372
373panic_on_unrecovered_nmi:
374
375The default Linux behaviour on an NMI of either memory or unknown is
376to continue operation. For many environments such as scientific
377computing it is preferable that the box is taken out and the error
378dealt with than an uncorrected parity/ECC error get propagated.
379
380A small number of systems do generate NMI's for bizarre random reasons
381such as power management so the default is off. That sysctl works like
382the existing panic controls already in that directory.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383
384==============================================================
385
386panic_on_oops:
387
388Controls the kernel's behaviour when an oops or BUG is encountered.
389
3900: try to continue operation
391
Matt LaPlantea982ac02007-05-09 07:35:06 +02003921: panic immediately. If the `panic' sysctl is also non-zero then the
Maxime Bizon8b23d04d2006-08-05 12:14:32 -0700393 machine will be rebooted.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394
395==============================================================
396
Mitsuo Hayasaka55af7792011-11-29 15:08:36 +0900397panic_on_stackoverflow:
398
399Controls the kernel's behavior when detecting the overflows of
400kernel, IRQ and exception stacks except a user stack.
401This file shows up if CONFIG_DEBUG_STACKOVERFLOW is enabled.
402
4030: try to continue operation.
404
4051: panic immediately.
406
407==============================================================
408
409
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410pid_max:
411
Robert P. J. Daybeb7dd82007-05-09 07:14:03 +0200412PID allocation wrap value. When the kernel's next PID value
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413reaches this value, it wraps back to a minimum PID value.
414PIDs of value pid_max or larger are not allocated.
415
416==============================================================
417
Pavel Emelyanovb8f566b2012-01-12 17:20:27 -0800418ns_last_pid:
419
420The last pid allocated in the current (the one task using this sysctl
421lives in) pid namespace. When selecting a pid for a next task on fork
422kernel tries to allocate a number starting from this one.
423
424==============================================================
425
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426powersave-nap: (PPC only)
427
428If set, Linux-PPC will use the 'nap' mode of powersaving,
429otherwise the 'doze' mode will be used.
430
431==============================================================
432
433printk:
434
435The four values in printk denote: console_loglevel,
436default_message_loglevel, minimum_console_loglevel and
437default_console_loglevel respectively.
438
439These values influence printk() behavior when printing or
440logging error messages. See 'man 2 syslog' for more info on
441the different loglevels.
442
443- console_loglevel: messages with a higher priority than
444 this will be printed to the console
Paul Bolle87889e12011-02-06 21:00:41 +0100445- default_message_loglevel: messages without an explicit priority
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 will be printed with this priority
447- minimum_console_loglevel: minimum (highest) value to which
448 console_loglevel can be set
449- default_console_loglevel: default value for console_loglevel
450
451==============================================================
452
Borislav Petkov807094c2011-07-23 10:39:29 -0700453printk_delay:
454
455Delay each printk message in printk_delay milliseconds
456
457Value from 0 - 10000 is allowed.
458
459==============================================================
460
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461printk_ratelimit:
462
463Some warning messages are rate limited. printk_ratelimit specifies
464the minimum length of time between these messages (in jiffies), by
465default we allow one every 5 seconds.
466
467A value of 0 will disable rate limiting.
468
469==============================================================
470
471printk_ratelimit_burst:
472
473While long term we enforce one message per printk_ratelimit
474seconds, we do allow a burst of messages to pass through.
475printk_ratelimit_burst specifies the number of messages we can
476send before ratelimiting kicks in.
477
478==============================================================
479
Borislav Petkov807094c2011-07-23 10:39:29 -0700480randomize_va_space:
Jiri Kosina1ec7fd52008-02-09 23:24:08 +0100481
482This option can be used to select the type of process address
483space randomization that is used in the system, for architectures
484that support this feature.
485
Horst Schirmeierb7f5ab62009-07-03 14:20:17 +02004860 - Turn the process address space randomization off. This is the
487 default for architectures that do not support this feature anyways,
488 and kernels that are booted with the "norandmaps" parameter.
Jiri Kosina1ec7fd52008-02-09 23:24:08 +0100489
4901 - Make the addresses of mmap base, stack and VDSO page randomized.
491 This, among other things, implies that shared libraries will be
Horst Schirmeierb7f5ab62009-07-03 14:20:17 +0200492 loaded to random addresses. Also for PIE-linked binaries, the
493 location of code start is randomized. This is the default if the
494 CONFIG_COMPAT_BRK option is enabled.
Jiri Kosina1ec7fd52008-02-09 23:24:08 +0100495
Horst Schirmeierb7f5ab62009-07-03 14:20:17 +02004962 - Additionally enable heap randomization. This is the default if
497 CONFIG_COMPAT_BRK is disabled.
498
499 There are a few legacy applications out there (such as some ancient
Jiri Kosina1ec7fd52008-02-09 23:24:08 +0100500 versions of libc.so.5 from 1996) that assume that brk area starts
Horst Schirmeierb7f5ab62009-07-03 14:20:17 +0200501 just after the end of the code+bss. These applications break when
502 start of the brk area is randomized. There are however no known
Jiri Kosina1ec7fd52008-02-09 23:24:08 +0100503 non-legacy applications that would be broken this way, so for most
Horst Schirmeierb7f5ab62009-07-03 14:20:17 +0200504 systems it is safe to choose full randomization.
505
506 Systems with ancient and/or broken binaries should be configured
507 with CONFIG_COMPAT_BRK enabled, which excludes the heap from process
508 address space randomization.
Jiri Kosina1ec7fd52008-02-09 23:24:08 +0100509
510==============================================================
511
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512reboot-cmd: (Sparc only)
513
514??? This seems to be a way to give an argument to the Sparc
515ROM/Flash boot loader. Maybe to tell it what to do after
516rebooting. ???
517
518==============================================================
519
520rtsig-max & rtsig-nr:
521
522The file rtsig-max can be used to tune the maximum number
523of POSIX realtime (queued) signals that can be outstanding
524in the system.
525
526rtsig-nr shows the number of RT signals currently queued.
527
528==============================================================
529
530sg-big-buff:
531
532This file shows the size of the generic SCSI (sg) buffer.
533You can't tune it just yet, but you could change it on
534compile time by editing include/scsi/sg.h and changing
535the value of SG_BIG_BUFF.
536
537There shouldn't be any reason to change this value. If
538you can come up with one, you probably know what you
539are doing anyway :)
540
541==============================================================
542
Borislav Petkov807094c2011-07-23 10:39:29 -0700543shmmax:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544
545This value can be used to query and set the run time limit
546on the maximum shared memory segment size that can be created.
Borislav Petkov807094c2011-07-23 10:39:29 -0700547Shared memory segments up to 1Gb are now supported in the
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548kernel. This value defaults to SHMMAX.
549
550==============================================================
551
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700552shm_rmid_forced:
553
554Linux lets you set resource limits, including how much memory one
555process can consume, via setrlimit(2). Unfortunately, shared memory
556segments are allowed to exist without association with any process, and
557thus might not be counted against any resource limits. If enabled,
558shared memory segments are automatically destroyed when their attach
559count becomes zero after a detach or a process termination. It will
560also destroy segments that were created, but never attached to, on exit
561from the process. The only use left for IPC_RMID is to immediately
562destroy an unattached segment. Of course, this breaks the way things are
563defined, so some applications might stop working. Note that this
564feature will do you no good unless you also configure your resource
565limits (in particular, RLIMIT_AS and RLIMIT_NPROC). Most systems don't
566need this.
567
568Note that if you change this from 0 to 1, already created segments
569without users and with a dead originative process will be destroyed.
570
571==============================================================
572
Ravikiran G Thirumalaic4f3b632007-10-16 23:26:09 -0700573softlockup_thresh:
574
Andrew Mortonb4d19cc2008-09-22 13:57:51 -0700575This value can be used to lower the softlockup tolerance threshold. The
576default threshold is 60 seconds. If a cpu is locked up for 60 seconds,
577the kernel complains. Valid values are 1-60 seconds. Setting this
578tunable to zero will disable the softlockup detection altogether.
Ravikiran G Thirumalaic4f3b632007-10-16 23:26:09 -0700579
580==============================================================
581
Borislav Petkov807094c2011-07-23 10:39:29 -0700582tainted:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583
584Non-zero if the kernel has been tainted. Numeric values, which
585can be ORed together:
586
Greg Kroah-Hartmanbb206982008-10-17 15:01:07 -0700587 1 - A module with a non-GPL license has been loaded, this
588 includes modules with no license.
589 Set by modutils >= 2.4.9 and module-init-tools.
590 2 - A module was force loaded by insmod -f.
591 Set by modutils >= 2.4.9 and module-init-tools.
592 4 - Unsafe SMP processors: SMP with CPUs not designed for SMP.
593 8 - A module was forcibly unloaded from the system by rmmod -f.
594 16 - A hardware machine check error occurred on the system.
595 32 - A bad page was discovered on the system.
596 64 - The user has asked that the system be marked "tainted". This
597 could be because they are running software that directly modifies
598 the hardware, or for other reasons.
599 128 - The system has died.
600 256 - The ACPI DSDT has been overridden with one supplied by the user
601 instead of using the one provided by the hardware.
602 512 - A kernel warning has occurred.
6031024 - A module from drivers/staging was loaded.
Larry Fingerf5fe1842012-02-06 09:49:50 -08006042048 - The system is working around a severe firmware bug.
6054096 - An out-of-tree module has been loaded.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606
Shen Feng760df932009-04-02 16:57:20 -0700607==============================================================
608
Shen Feng760df932009-04-02 16:57:20 -0700609unknown_nmi_panic:
610
Borislav Petkov807094c2011-07-23 10:39:29 -0700611The value in this file affects behavior of handling NMI. When the
612value is non-zero, unknown NMI is trapped and then panic occurs. At
613that time, kernel debugging information is displayed on console.
Shen Feng760df932009-04-02 16:57:20 -0700614
Borislav Petkov807094c2011-07-23 10:39:29 -0700615NMI switch that most IA32 servers have fires unknown NMI up, for
616example. If a system hangs up, try pressing the NMI switch.