From 01573e231f18eb2d99162747186f59511f56b64d Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 08 Dec 2023 10:40:48 +0000
Subject: [PATCH] 移去rt
---
kernel/Documentation/admin-guide/sysrq.rst | 52 +++++++++++++++++++++++++++-------------------------
1 files changed, 27 insertions(+), 25 deletions(-)
diff --git a/kernel/Documentation/admin-guide/sysrq.rst b/kernel/Documentation/admin-guide/sysrq.rst
index 7b9035c..67dfa4c 100644
--- a/kernel/Documentation/admin-guide/sysrq.rst
+++ b/kernel/Documentation/admin-guide/sysrq.rst
@@ -48,9 +48,10 @@
How do I use the magic SysRq key?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-On x86 - You press the key combo :kbd:`ALT-SysRq-<command key>`.
+On x86
+ You press the key combo :kbd:`ALT-SysRq-<command key>`.
-.. note::
+ .. note::
Some
keyboards may not have a key labeled 'SysRq'. The 'SysRq' key is
also known as the 'Print Screen' key. Also some keyboards cannot
@@ -58,14 +59,15 @@
have better luck with press :kbd:`Alt`, press :kbd:`SysRq`,
release :kbd:`SysRq`, press :kbd:`<command key>`, release everything.
-On SPARC - You press :kbd:`ALT-STOP-<command key>`, I believe.
+On SPARC
+ You press :kbd:`ALT-STOP-<command key>`, I believe.
On the serial console (PC style standard serial ports only)
You send a ``BREAK``, then within 5 seconds a command key. Sending
``BREAK`` twice is interpreted as a normal BREAK.
On PowerPC
- Press :kbd:`ALT - Print Screen` (or :kbd:`F13`) - :kbd:`<command key>`,
+ Press :kbd:`ALT - Print Screen` (or :kbd:`F13`) - :kbd:`<command key>`.
:kbd:`Print Screen` (or :kbd:`F13`) - :kbd:`<command key>` may suffice.
On other
@@ -73,9 +75,11 @@
let me know so I can add them to this section.
On all
- write a character to /proc/sysrq-trigger. e.g.::
+ Write a character to /proc/sysrq-trigger. e.g.::
echo t > /proc/sysrq-trigger
+
+The :kbd:`<command key>` is case sensitive.
What are the 'command' keys?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -171,22 +175,20 @@
useful when you want to exit a program that will not let you switch consoles.
(For example, X or a svgalib program.)
-``reboot(b)`` is good when you're unable to shut down. But you should also
-``sync(s)`` and ``umount(u)`` first.
+``reboot(b)`` is good when you're unable to shut down, it is an equivalent
+of pressing the "reset" button.
``crash(c)`` can be used to manually trigger a crashdump when the system is hung.
Note that this just triggers a crash if there is no dump mechanism available.
-``sync(s)`` is great when your system is locked up, it allows you to sync your
-disks and will certainly lessen the chance of data loss and fscking. Note
-that the sync hasn't taken place until you see the "OK" and "Done" appear
-on the screen. (If the kernel is really in strife, you may not ever get the
-OK or Done message...)
+``sync(s)`` is handy before yanking removable medium or after using a rescue
+shell that provides no graceful shutdown -- it will ensure your data is
+safely written to the disk. Note that the sync hasn't taken place until you see
+the "OK" and "Done" appear on the screen.
-``umount(u)`` is basically useful in the same ways as ``sync(s)``. I generally
-``sync(s)``, ``umount(u)``, then ``reboot(b)`` when my system locks. It's saved
-me many a fsck. Again, the unmount (remount read-only) hasn't taken place until
-you see the "OK" and "Done" message appear on the screen.
+``umount(u)`` can be used to mark filesystems as properly unmounted. From the
+running system's point of view, they will be remounted read-only. The remount
+isn't complete until you see the "OK" and "Done" message appear on the screen.
The loglevels ``0``-``9`` are useful when your console is being flooded with
kernel messages you do not want to see. Selecting ``0`` will prevent all but
@@ -231,13 +233,13 @@
handler is called. Your handler must conform to the prototype in 'sysrq.h'.
After the ``sysrq_key_op`` is created, you can call the kernel function
-``register_sysrq_key(int key, struct sysrq_key_op *op_p);`` this will
+``register_sysrq_key(int key, const struct sysrq_key_op *op_p);`` this will
register the operation pointed to by ``op_p`` at table key 'key',
if that slot in the table is blank. At module unload time, you must call
-the function ``unregister_sysrq_key(int key, struct sysrq_key_op *op_p)``, which
-will remove the key op pointed to by 'op_p' from the key 'key', if and only if
-it is currently registered in that slot. This is in case the slot has been
-overwritten since you registered it.
+the function ``unregister_sysrq_key(int key, const struct sysrq_key_op *op_p)``,
+which will remove the key op pointed to by 'op_p' from the key 'key', if and
+only if it is currently registered in that slot. This is in case the slot has
+been overwritten since you registered it.
The Magic SysRQ system works by registering key operations against a key op
lookup table, which is defined in 'drivers/tty/sysrq.c'. This key table has
@@ -284,7 +286,7 @@
Credits
~~~~~~~
-Written by Mydraal <vulpyne@vulpyne.net>
-Updated by Adam Sulmicki <adam@cfar.umd.edu>
-Updated by Jeremy M. Dolan <jmd@turbogeek.org> 2001/01/28 10:15:59
-Added to by Crutcher Dunnavant <crutcher+kernel@datastacks.com>
+- Written by Mydraal <vulpyne@vulpyne.net>
+- Updated by Adam Sulmicki <adam@cfar.umd.edu>
+- Updated by Jeremy M. Dolan <jmd@turbogeek.org> 2001/01/28 10:15:59
+- Added to by Crutcher Dunnavant <crutcher+kernel@datastacks.com>
--
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