projects/linux·commit 4302fbc8

panic: panic=-1 for immediate reboot

4302fbc8 · Hugh Dickins <[email protected]> · 2011-07-26 16:08:52 -07:00

When a kernel BUG or oops occurs, ChromeOS intends to panic and
immediately reboot, with stacktrace and other messages preserved in RAM
across reboot.

But the longer we delay, the more likely the user is to poweroff and
lose the info.

panic_timeout (seconds before rebooting) is set by panic= boot option or
sysctl or /proc/sys/kernel/panic; but 0 means wait forever, so at
present we have to delay at least 1 second.

Let a negative number mean reboot immediately (with the small cosmetic
benefit of suppressing that newline-less "Rebooting in %d seconds.."
message).

Signed-off-by: Hugh Dickins <[email protected]>
Signed-off-by: Mandeep Singh Baines <[email protected]>
Cc: Huang Ying <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Olaf Hering <[email protected]>
Cc: Jesse Barnes <[email protected]>
Cc: Dave Airlie <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Alan Cox <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Commit
4302fbc8ec2ccae279c939f241bf8ce64e1a0bb7
Parents
3f0fb4e8

Changes

2 files changed · +5 −1

FileStatusAddDelContent
Documentation/kernel-parameters.txtmodified+3−1View file
kernel/panic.cmodified+2−0View file

Documentation/kernel-parameters.txt

View file
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index a70e43e..4ca9389 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1846,7 +1846,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
See Documentation/sound/oss/oss-parameters.txt
panic= [KNL] Kernel behaviour on panic: delay <timeout>
- seconds before rebooting
+ timeout > 0: seconds before rebooting
+ timeout = 0: wait forever
+ timeout < 0: reboot immediately
Format: <timeout>
parkbd.port= [HW] Parallel port number the keyboard adapter is

kernel/panic.c

View file
diff --git a/kernel/panic.c b/kernel/panic.c
index 6923167..d7bb697 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -119,6 +119,8 @@ NORET_TYPE void panic(const char * fmt, ...)
}
mdelay(PANIC_TIMER_STEP);
}
+ }
+ if (panic_timeout != 0) {
/*
* This will not be a clean reboot, with everything
* shutting down. But if there is a chance of