sched: Isolate preempt counting in its own config option

Create a new CONFIG_PREEMPT_COUNT that handles the inc/dec
of preempt count offset independently. So that the offset
can be updated by preempt_disable() and preempt_enable()
even without the need for CONFIG_PREEMPT beeing set.

This prepares to make CONFIG_DEBUG_SPINLOCK_SLEEP working
with !CONFIG_PREEMPT where it currently doesn't detect
code that sleeps inside explicit preemption disabled
sections.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 716875e53520..8e38d4c140ff 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -134,7 +134,7 @@ static inline int page_cache_get_speculative(struct page *page)
         VM_BUG_ON(in_interrupt());
 
 #if !defined(CONFIG_SMP) && defined(CONFIG_TREE_RCU)
-# ifdef CONFIG_PREEMPT
+# ifdef CONFIG_PREEMPT_COUNT
         VM_BUG_ON(!in_atomic());
 # endif
         /*
@@ -172,7 +172,7 @@ static inline int page_cache_add_speculative(struct page *page, int count)
         VM_BUG_ON(in_interrupt());
 
 #if !defined(CONFIG_SMP) && defined(CONFIG_TREE_RCU)
-# ifdef CONFIG_PREEMPT
+# ifdef CONFIG_PREEMPT_COUNT
         VM_BUG_ON(!in_atomic());
 # endif
         VM_BUG_ON(page_count(page) == 0);