[PATCH] Revert "sched: improve preempt debugging"

From: Ingo Molnar
Date: Mon Jan 12 2009 - 07:00:50 EST


This reverts commit 7317d7b87edb41a9135e30be1ec3f7ef817c53dd.

This has been reported (and bisected) by Alexey Zaytsev and
Kamalesh Babulal to produce annoying warnings during bootup
on both x86 and powerpc.

kernel_locked() is not a valid test in IRQ context (we update the
BKL's ->lock_depth and the preempt count separately and non-atomicalyy),
so we cannot put it into the generic preempt debugging checks which
can run in IRQ contexts too.

Reported-and-bisected-by: Alexey Zaytsev <alexey.zaytsev@xxxxxxxxx>
Reported-and-bisected-by: Kamalesh Babulal <kamalesh@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
kernel/sched.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/sched.c b/kernel/sched.c
index 8be2c13..3b630d8 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4440,7 +4440,7 @@ void __kprobes sub_preempt_count(int val)
/*
* Underflow?
*/
- if (DEBUG_LOCKS_WARN_ON(val > preempt_count() - (!!kernel_locked())))
+ if (DEBUG_LOCKS_WARN_ON(val > preempt_count()))
return;
/*
* Is the spinlock portion underflowing?
--
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