[PATCH] Documentation: Refresh sysctl/kernel.txt
From: Borislav Petkov
Date: Sat Jul 16 2011 - 04:23:47 EST
More specifically,
- drop stale index entries
- sync and sort index and entries
- reflow sticking out paragraphs to colwidth 72
- correct typos
- cleanup whitespace
Signed-off-by: Borislav Petkov <bp@xxxxxxxxx>
---
Documentation/sysctl/kernel.txt | 215 ++++++++++++++++++++-------------------
1 files changed, 110 insertions(+), 105 deletions(-)
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index 5e7cb39..1c7fb0a 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -17,23 +17,21 @@ before actually making adjustments.
Currently, these files might (depending on your configuration)
show up in /proc/sys/kernel:
-- acpi_video_flags
+
- acct
+- acpi_video_flags
+- auto_msgmni
- bootloader_type [ X86 only ]
- bootloader_version [ X86 only ]
- callhome [ S390 only ]
-- auto_msgmni
- core_pattern
- core_pipe_limit
- core_uses_pid
- ctrl-alt-del
-- dentry-state
- dmesg_restrict
- domainname
- hostname
- hotplug
-- java-appletviewer [ binfmt_java, obsolete ]
-- java-interpreter [ binfmt_java, obsolete ]
- kptr_restrict
- kstack_depth_to_print [ X86 only ]
- l2cr [ PPC only ]
@@ -48,10 +46,14 @@ show up in /proc/sys/kernel:
- overflowgid
- overflowuid
- panic
+- panic_on_oops
+- panic_on_unrecovered_nmi
- pid_max
- powersave-nap [ PPC only ]
-- panic_on_unrecovered_nmi
- printk
+- printk_delay
+- printk_ratelimit
+- printk_ratelimit_burst
- randomize_va_space
- real-root-dev ==> Documentation/initrd.txt
- reboot-cmd [ SPARC only ]
@@ -62,6 +64,7 @@ show up in /proc/sys/kernel:
- shmall
- shmmax [ sysv ipc ]
- shmmni
+- softlockup_thresh
- stop-a [ SPARC only ]
- sysrq ==> Documentation/sysrq.txt
- tainted
@@ -71,15 +74,6 @@ show up in /proc/sys/kernel:
==============================================================
-acpi_video_flags:
-
-flags
-
-See Doc*/kernel/power/video.txt, it allows mode of video boot to be
-set during run time.
-
-==============================================================
-
acct:
highwater lowwater frequency
@@ -97,6 +91,25 @@ valid for 30 seconds.
==============================================================
+acpi_video_flags:
+
+flags
+
+See Doc*/kernel/power/video.txt, it allows mode of video boot to be
+set during run time.
+
+==============================================================
+
+auto_msgmni:
+
+Enables/Disables automatic recomputing of msgmni upon memory add/remove
+or upon ipc namespace creation/removal (see the msgmni description
+above). Echoing "1" into this file enables msgmni automatic recomputing.
+Echoing "0" turns it off. auto_msgmni default value is 1.
+
+
+==============================================================
+
bootloader_type:
x86 bootloader identification
@@ -172,22 +185,24 @@ core_pattern is used to specify a core dumpfile pattern name.
core_pipe_limit:
-This sysctl is only applicable when core_pattern is configured to pipe core
-files to a user space helper (when the first character of core_pattern is a '|',
-see above). When collecting cores via a pipe to an application, it is
-occasionally useful for the collecting application to gather data about the
-crashing process from its /proc/pid directory. In order to do this safely, the
-kernel must wait for the collecting process to exit, so as not to remove the
-crashing processes proc files prematurely. This in turn creates the possibility
-that a misbehaving userspace collecting process can block the reaping of a
-crashed process simply by never exiting. This sysctl defends against that. It
-defines how many concurrent crashing processes may be piped to user space
-applications in parallel. If this value is exceeded, then those crashing
-processes above that value are noted via the kernel log and their cores are
-skipped. 0 is a special value, indicating that unlimited processes may be
-captured in parallel, but that no waiting will take place (i.e. the collecting
-process is not guaranteed access to /proc/<crashing pid>/). This value defaults
-to 0.
+This sysctl is only applicable when core_pattern is configured to pipe
+core files to a user space helper (when the first character of
+core_pattern is a '|', see above). When collecting cores via a pipe
+to an application, it is occasionally useful for the collecting
+application to gather data about the crashing process from its
+/proc/pid directory. In order to do this safely, the kernel must wait
+for the collecting process to exit, so as not to remove the crashing
+processes proc files prematurely. This in turn creates the
+possibility that a misbehaving userspace collecting process can block
+the reaping of a crashed process simply by never exiting. This sysctl
+defends against that. It defines how many concurrent crashing
+processes may be piped to user space applications in parallel. If
+this value is exceeded, then those crashing processes above that value
+are noted via the kernel log and their cores are skipped. 0 is a
+special value, indicating that unlimited processes may be captured in
+parallel, but that no waiting will take place (i.e. the collecting
+process is not guaranteed access to /proc/<crashing pid>/). This
+value defaults to 0.
==============================================================
@@ -218,14 +233,14 @@ to decide what to do with it.
dmesg_restrict:
-This toggle indicates whether unprivileged users are prevented from using
-dmesg(8) to view messages from the kernel's log buffer. When
-dmesg_restrict is set to (0) there are no restrictions. When
+This toggle indicates whether unprivileged users are prevented
+from using dmesg(8) to view messages from the kernel's log buffer.
+When dmesg_restrict is set to (0) there are no restrictions. When
dmesg_restrict is set set to (1), users must have CAP_SYSLOG to use
dmesg(8).
-The kernel config option CONFIG_SECURITY_DMESG_RESTRICT sets the default
-value of dmesg_restrict.
+The kernel config option CONFIG_SECURITY_DMESG_RESTRICT sets the
+default value of dmesg_restrict.
==============================================================
@@ -256,13 +271,6 @@ Default value is "/sbin/hotplug".
==============================================================
-l2cr: (PPC only)
-
-This flag controls the L2 cache of G3 processor boards. If
-0, the cache is disabled. Enabled if nonzero.
-
-==============================================================
-
kptr_restrict:
This toggle indicates whether restrictions are placed on
@@ -283,6 +291,13 @@ kernel stack.
==============================================================
+l2cr: (PPC only)
+
+This flag controls the L2 cache of G3 processor boards. If
+0, the cache is disabled. Enabled if nonzero.
+
+==============================================================
+
modules_disabled:
A toggle value indicating if modules are allowed to be loaded
@@ -293,6 +308,21 @@ to false.
==============================================================
+nmi_watchdog:
+
+Enables/Disables the NMI watchdog on x86 systems. When the value is
+non-zero the NMI watchdog is enabled and will continuously test all
+online cpus to determine whether or not they are still functioning
+properly. Currently, passing "nmi_watchdog=" parameter at boot time is
+required for this function to work.
+
+If LAPIC NMI watchdog method is in use (nmi_watchdog=2 kernel
+parameter), the NMI watchdog shares registers with oprofile. By
+disabling the NMI watchdog, oprofile may have more registers to
+utilize.
+
+==============================================================
+
osrelease, ostype & version:
# cat osrelease
@@ -312,10 +342,10 @@ The only way to tune these values is to rebuild the kernel :-)
overflowgid & overflowuid:
-if your architecture did not always support 32-bit UIDs (i.e. arm, i386,
-m68k, sh, and sparc32), a fixed UID and GID will be returned to
-applications that use the old 16-bit UID/GID system calls, if the actual
-UID or GID would exceed 65535.
+if your architecture did not always support 32-bit UIDs (i.e. arm,
+i386, m68k, sh, and sparc32), a fixed UID and GID will be returned to
+applications that use the old 16-bit UID/GID system calls, if the
+actual UID or GID would exceed 65535.
These sysctls allow you to change the value of the fixed UID and GID.
The default is 65534.
@@ -324,9 +354,22 @@ The default is 65534.
panic:
-The value in this file represents the number of seconds the
-kernel waits before rebooting on a panic. When you use the
-software watchdog, the recommended setting is 60.
+The value in this file represents the number of seconds the kernel
+waits before rebooting on a panic. When you use the software watchdog,
+the recommended setting is 60.
+
+==============================================================
+
+panic_on_unrecovered_nmi:
+
+The default Linux behaviour on an NMI of either memory or unknown is
+to continue operation. For many environments such as scientific
+computing it is preferable that the box is taken out and the error
+dealt with than an uncorrected parity/ECC error get propagated.
+
+A small number of systems do generate NMI's for bizarre random reasons
+such as power management so the default is off. That sysctl works like
+the existing panic controls already in that directory.
==============================================================
@@ -376,6 +419,14 @@ the different loglevels.
==============================================================
+printk_delay:
+
+Delay each printk message in printk_delay milliseconds
+
+Value from 0 - 10000 is allowed.
+
+==============================================================
+
printk_ratelimit:
Some warning messages are rate limited. printk_ratelimit specifies
@@ -395,15 +446,7 @@ send before ratelimiting kicks in.
==============================================================
-printk_delay:
-
-Delay each printk message in printk_delay milliseconds
-
-Value from 0 - 10000 is allowed.
-
-==============================================================
-
-randomize-va-space:
+randomize_va_space:
This option can be used to select the type of process address
space randomization that is used in the system, for architectures
@@ -466,11 +509,11 @@ are doing anyway :)
==============================================================
-shmmax:
+shmmax:
This value can be used to query and set the run time limit
on the maximum shared memory segment size that can be created.
-Shared memory segments up to 1Gb are now supported in the
+Shared memory segments up to 1Gb are now supported in the
kernel. This value defaults to SHMMAX.
==============================================================
@@ -484,7 +527,7 @@ tunable to zero will disable the softlockup detection altogether.
==============================================================
-tainted:
+tainted:
Non-zero if the kernel has been tainted. Numeric values, which
can be ORed together:
@@ -509,49 +552,11 @@ can be ORed together:
==============================================================
-auto_msgmni:
-
-Enables/Disables automatic recomputing of msgmni upon memory add/remove or
-upon ipc namespace creation/removal (see the msgmni description above).
-Echoing "1" into this file enables msgmni automatic recomputing.
-Echoing "0" turns it off.
-auto_msgmni default value is 1.
-
-==============================================================
-
-nmi_watchdog:
-
-Enables/Disables the NMI watchdog on x86 systems. When the value is non-zero
-the NMI watchdog is enabled and will continuously test all online cpus to
-determine whether or not they are still functioning properly. Currently,
-passing "nmi_watchdog=" parameter at boot time is required for this function
-to work.
-
-If LAPIC NMI watchdog method is in use (nmi_watchdog=2 kernel parameter), the
-NMI watchdog shares registers with oprofile. By disabling the NMI watchdog,
-oprofile may have more registers to utilize.
-
-==============================================================
-
unknown_nmi_panic:
-The value in this file affects behavior of handling NMI. When the value is
-non-zero, unknown NMI is trapped and then panic occurs. At that time, kernel
-debugging information is displayed on console.
-
-NMI switch that most IA32 servers have fires unknown NMI up, for example.
-If a system hangs up, try pressing the NMI switch.
-
-==============================================================
-
-panic_on_unrecovered_nmi:
-
-The default Linux behaviour on an NMI of either memory or unknown is to continue
-operation. For many environments such as scientific computing it is preferable
-that the box is taken out and the error dealt with than an uncorrected
-parity/ECC error get propogated.
-
-A small number of systems do generate NMI's for bizarre random reasons such as
-power management so the default is off. That sysctl works like the existing
-panic controls already in that directory.
+The value in this file affects behavior of handling NMI. When the
+value is non-zero, unknown NMI is trapped and then panic occurs. At
+that time, kernel debugging information is displayed on console.
+NMI switch that most IA32 servers have fires unknown NMI up, for
+example. If a system hangs up, try pressing the NMI switch.
--
1.7.5.3.401.gfb674
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