[tip:tracing/urgent] tracing: Fix lockdep warning in global_clock()

From: tip-bot for Li Zefan
Date: Sat Apr 03 2010 - 05:28:42 EST


Commit-ID: e36673ec5126f15a8cddf6049aede7bdcf484c26
Gitweb: http://git.kernel.org/tip/e36673ec5126f15a8cddf6049aede7bdcf484c26
Author: Li Zefan <lizf@xxxxxxxxxxxxxx>
AuthorDate: Wed, 24 Mar 2010 10:57:37 +0800
Committer: Steven Rostedt <rostedt@xxxxxxxxxxx>
CommitDate: Mon, 29 Mar 2010 15:16:44 -0400

tracing: Fix lockdep warning in global_clock()

# echo 1 > events/enable
# echo global > trace_clock

------------[ cut here ]------------
WARNING: at kernel/lockdep.c:3162 check_flags+0xb2/0x190()
...
---[ end trace 3f86734a89416623 ]---
possible reason: unannotated irqs-on.
...

There's no reason to use the raw_local_irq_save() in trace_clock_global.
The local_irq_save() version is fine, and does not cause the bug in lockdep.

Acked-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Signed-off-by: Li Zefan <lizf@xxxxxxxxxxxxxx>
LKML-Reference: <4BA97FA1.7030606@xxxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
kernel/trace/trace_clock.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace_clock.c b/kernel/trace/trace_clock.c
index 6fbfb8f..9d589d8 100644
--- a/kernel/trace/trace_clock.c
+++ b/kernel/trace/trace_clock.c
@@ -84,7 +84,7 @@ u64 notrace trace_clock_global(void)
int this_cpu;
u64 now;

- raw_local_irq_save(flags);
+ local_irq_save(flags);

this_cpu = raw_smp_processor_id();
now = cpu_clock(this_cpu);
@@ -110,7 +110,7 @@ u64 notrace trace_clock_global(void)
arch_spin_unlock(&trace_clock_struct.lock);

out:
- raw_local_irq_restore(flags);
+ local_irq_restore(flags);

return now;
}
--
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