X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=Documentation%2Fsysrq.txt;h=ad0bedf678b39cbddfb00d23523f4a3e02a851df;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=f98c2e31c143e6a114f61feaef725f4422e3b028;hpb=f7f1b0f1e2fbadeab12d24236000e778aa9b1ead;p=linux-2.6.git diff --git a/Documentation/sysrq.txt b/Documentation/sysrq.txt index f98c2e31c..ad0bedf67 100644 --- a/Documentation/sysrq.txt +++ b/Documentation/sysrq.txt @@ -72,6 +72,8 @@ On all - write a character to /proc/sysrq-trigger. eg: 'b' - Will immediately reboot the system without syncing or unmounting your disks. +'c' - Will perform a kexec reboot in order to take a crashdump. + 'o' - Will shut your system off (if configured and supported). 's' - Will attempt to sync all mounted filesystems. @@ -122,6 +124,9 @@ useful when you want to exit a program that will not let you switch consoles. re'B'oot is good when you're unable to shut down. But you should also 'S'ync and 'U'mount first. +'C'rashdump can be used to manually trigger a crashdump when the system is hung. +The kernel needs to have been built with CONFIG_KEXEC enabled. + 'S'ync 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 @@ -166,7 +171,7 @@ the header 'include/linux/sysrq.h', this will define everything else you need. Next, you must create a sysrq_key_op struct, and populate it with A) the key handler function you will use, B) a help_msg string, that will print when SysRQ prints help, and C) an action_msg string, that will print right before your -handler is called. Your handler must conform to the protoype in 'sysrq.h'. +handler is called. Your handler must conform to the prototype in 'sysrq.h'. After the sysrq_key_op is created, you can call the macro register_sysrq_key(int key, struct sysrq_key_op *op_p) that is defined in @@ -197,17 +202,13 @@ you must call __handle_sysrq_nolock instead. * I have more questions, who can I ask? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -You may feel free to send email to myrdraal@deathsdoor.com, and I will -respond as soon as possible. - -Myrdraal - And I'll answer any questions about the registration system you got, also responding as soon as possible. -Crutcher * Credits ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -Written by Mydraal +Written by Mydraal Updated by Adam Sulmicki Updated by Jeremy M. Dolan 2001/01/28 10:15:59 Added to by Crutcher Dunnavant