[tip:sched/urgent] x86, tsc: Fix a preemption leak in restore_sched_clock_state()

From: tip-bot for Peter Zijlstra
Date: Sat Sep 11 2010 - 03:50:45 EST


Commit-ID: 55496c896b8a695140045099d4e0175cf09d4eae
Gitweb: http://git.kernel.org/tip/55496c896b8a695140045099d4e0175cf09d4eae
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Fri, 10 Sep 2010 22:32:53 +0200
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Sat, 11 Sep 2010 09:47:07 +0200

x86, tsc: Fix a preemption leak in restore_sched_clock_state()

Doh, a real life genuine preemption leak..

This caused a suspend failure.

Reported-bisected-and-tested-by-the-invaluable: Jeff Chua <jeff.chua.linux@xxxxxxxxx>
Acked-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Rafael J. Wysocki <rjw@xxxxxxx>
Cc: Nico Schottelius <nico-linux-20100709@xxxxxxxxxxxxxxx>
Cc: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Florian Pritz <flo@xxxxxxx>
Cc: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
Cc: Len Brown <lenb@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxx> # Greg, please apply after: cd7240c ("x86, tsc, sched: Recompute cyc2ns_offset's during resume from")
sleep states
LKML-Reference: <1284150773.402.122.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/x86/kernel/tsc.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index d632934..26a863a 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -655,7 +655,7 @@ void restore_sched_clock_state(void)

local_irq_save(flags);

- get_cpu_var(cyc2ns_offset) = 0;
+ __get_cpu_var(cyc2ns_offset) = 0;
offset = cyc2ns_suspend - sched_clock();

for_each_possible_cpu(cpu)
--
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