[tip:core/locking] init/main.c: Execute lockdep_init() as early as possible

[tip-bot for Ming Lei]

Commit-ID:  73839c5b2eacc15cb0aa79c69b285fc659fa8851
Gitweb:     http://git.kernel.org/tip/73839c5b2eacc15cb0aa79c69b285fc659fa8851
Author:     Ming Lei <tom.leiming@xxxxxxxxx>
AuthorDate: Thu, 17 Nov 2011 13:34:31 +0800
Committer:  Ingo Molnar <mingo@xxxxxxx>
CommitDate: Tue, 6 Dec 2011 08:16:53 +0100

init/main.c: Execute lockdep_init() as early as possible

This patch fixes a lockdep warning on ARM platforms:

  [    0.000000] WARNING: lockdep init error! Arch code didn't call lockdep_init() early enough?
  [    0.000000] Call stack leading to lockdep invocation was:
  [    0.000000]  [<c00164bc>] save_stack_trace_tsk+0x0/0x90
  [    0.000000]  [<ffffffff>] 0xffffffff

The warning is caused by printk inside smp_setup_processor_id().

It is safe to do this because lockdep_init() doesn't depend on
smp_setup_processor_id(), so improve things that printk can be
called as early as possible without lockdep complaint.

Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx>
Reviewed-by: Yong Zhang <yong.zhang0@xxxxxxxxx>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1321508072-23853-1-git-send-email-tom.leiming@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
 init/main.c |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/init/main.c b/init/main.c
index 217ed23..2c76efb 100644
--- a/init/main.c
+++ b/init/main.c
@@ -469,13 +469,12 @@ asmlinkage void __init start_kernel(void)
 	char * command_line;
 	extern const struct kernel_param __start___param[], __stop___param[];
 
-	smp_setup_processor_id();
-
 	/*
 	 * Need to run as early as possible, to initialize the
 	 * lockdep hash:
 	 */
 	lockdep_init();
+	smp_setup_processor_id();
 	debug_objects_early_init();
 
 	/*
--
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