Commit e2a8b0a7 authored by zhangwei(Jovi)'s avatar zhangwei(Jovi) Committed by Linus Torvalds
Browse files

Documentation/sysrq: fix inconstistent help message of sysrq key 



Currently help message of /proc/sysrq-trigger highlight its
upper-case characters, like below:

      SysRq : HELP : loglevel(0-9) reBoot Crash terminate-all-tasks(E)
      memory-full-oom-kill(F) kill-all-tasks(I) ...

this would confuse user trigger sysrq by upper-case character, which is
inconsistent with the real lower-case character registed key.

This inconsistent help message will also lead more confused when
26 upper-case letters put into use in future.

This patch fix sysrq documentation.

Signed-off-by: default avatarzhangwei(Jovi) <jovi.zhangwei@huawei.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7b6b99a0

Documentation/sysrq.txt

+10 −10
Original line number Diff line number Diff line
@@ -129,9 +129,9 @@ On all - write a character to /proc/sysrq-trigger. e.g.: 


*  Okay, so what can I use them for?

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Well, un'R'aw is very handy when your X server or a svgalib program crashes.

Well, unraw(r) is very handy when your X server or a svgalib program crashes.



sa'K' (Secure Access Key) is useful when you want to be sure there is no

sak(k) (Secure Access Key) is useful when you want to be sure there is no

trojan program running at console which could grab your password

when you would try to login. It will kill all programs on given console,

thus letting you make sure that the login prompt you see is actually
@@ -143,20 +143,20 @@ IMPORTANT: such. :IMPORTANT 
useful when you want to exit a program that will not let you switch consoles.

(For example, X or a svgalib program.)



re'B'oot is good when you're unable to shut down. But you should also 'S'ync

and 'U'mount first.

reboot(b) is good when you're unable to shut down. But you should also

sync(s) and umount(u) first.



'C'rash can be used to manually trigger a crashdump when the system is hung.

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.



'S'ync is great when your system is locked up, it allows you to sync your

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...)



'U'mount is basically useful in the same ways as 'S'ync. I generally 'S'ync,

'U'mount, then re'B'oot when my system locks. It's saved me many a fsck.

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.
@@ -165,11 +165,11 @@ kernel messages you do not want to see. Selecting '0' will prevent all but 
the most urgent kernel messages from reaching your console. (They will

still be logged if syslogd/klogd are alive, though.)



t'E'rm and k'I'll are useful if you have some sort of runaway process you

term(e) and kill(i) are useful if you have some sort of runaway process you

are unable to kill any other way, especially if it's spawning other

processes.



"'J'ust thaw it" is useful if your system becomes unresponsive due to a frozen

"just thaw it(j)" is useful if your system becomes unresponsive due to a frozen

(probably root) filesystem via the FIFREEZE ioctl.



*  Sometimes SysRq seems to get 'stuck' after using it, what can I do?

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