From 4302fbc8ec2ccae279c939f241bf8ce64e1a0bb7 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Tue, 26 Jul 2011 16:08:52 -0700 Subject: panic: panic=-1 for immediate reboot 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 Signed-off-by: Mandeep Singh Baines Cc: Huang Ying Cc: Andi Kleen Cc: Hugh Dickins Cc: Olaf Hering Cc: Jesse Barnes Cc: Dave Airlie Cc: Greg Kroah-Hartman Cc: Alan Cox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/kernel-parameters.txt | 4 +++- kernel/panic.c | 2 ++ 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index a70e43edcb6..4ca93898fbd 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 - seconds before rebooting + timeout > 0: seconds before rebooting + timeout = 0: wait forever + timeout < 0: reboot immediately Format: parkbd.port= [HW] Parallel port number the keyboard adapter is diff --git a/kernel/panic.c b/kernel/panic.c index 69231670eb9..d7bb6974efb 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 -- cgit v1.2.3-70-g09d2