From: Ingo Molnar <mingo@elte.hu>
Date: Sun, 29 Jun 2008 13:01:59 +0000 (+0200)
Subject: sched: sched_clock_cpu() based cpu_clock(), lockdep fix
X-Git-Tag: v2.6.27-rc1~1105^2~9
X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=commitdiff_plain;h=2d452c9b10caeec455eb5e56a0ef4ed485178213

sched: sched_clock_cpu() based cpu_clock(), lockdep fix

Vegard Nossum reported:

> WARNING: at kernel/lockdep.c:2738 check_flags+0x142/0x160()

which happens due to:

 unsigned long long cpu_clock(int cpu)
 {
         unsigned long long clock;
         unsigned long flags;

         raw_local_irq_save(flags);

as lower level functions can take locks, we must not do that, use
proper lockdep-annotated irq save/restore.

Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c
index ed5a8c4..60094e2 100644
--- a/kernel/sched_clock.c
+++ b/kernel/sched_clock.c
@@ -250,9 +250,9 @@ unsigned long long cpu_clock(int cpu)
 	unsigned long long clock;
 	unsigned long flags;
 
-	raw_local_irq_save(flags);
+	local_irq_save(flags);
 	clock = sched_clock_cpu(cpu);
-	raw_local_irq_restore(flags);
+	local_irq_restore(flags);
 
 	return clock;
 }