MIPS: Add arch_trigger_all_cpu_backtrace() function
authorEunbong Song <eunb.song@samsung.com>
Wed, 22 Oct 2014 06:39:56 +0000 (06:39 +0000)
committerRalf Baechle <ralf@linux-mips.org>
Mon, 24 Nov 2014 06:44:49 +0000 (07:44 +0100)
commit856839b76836a2ee524a8638f568275da57f719c
treef0aff422237181b79cceb891794aa532151f3983
parent635c99070600ff04b4c1d5afe67f051631a8397c
MIPS: Add arch_trigger_all_cpu_backtrace() function

Currently, arch_trigger_all_cpu_backtrace() is defined in only x86 and
sparc which have an NMI.  But in case of softlockup, it could be possible
to dump backtrace of all cpus. and this could be helpful for debugging.

for example, if system has 2 cpus.

CPU 0 CPU 1
 acquire read_lock()

try to do write_lock()

 ,,,
 missing read_unlock()

In this case, softlockup will occur becasuse CPU 0 does not call
read_unlock().  And dump_stack() print only backtrace for "CPU 0". If
CPU1's backtrace is printed it's very helpful.

[ralf@linux-mips.org: Fixed whitespace and formatting issues.]

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8200/
arch/mips/include/asm/irq.h
arch/mips/kernel/process.c