vm: adjust ifdef for TINY_RCU

There is an ifdef in page_cache_get_speculative() that checks for !SMP
and TREE_RCU, which has been an impossible combination since the advent
of TINY_RCU.  The ifdef enables a fastpath that is valid when preemption
is disabled by rcu_read_lock() in UP systems, which is the case when
TINY_RCU is enabled.  This commit therefore adjusts the ifdef to
generate the fastpath when TINY_RCU is enabled.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Paul E. McKenney 2013-04-29 15:06:13 -07:00 committed by Linus Torvalds
parent 250297edf8
commit 8375ad98cc

View File

@ -149,7 +149,7 @@ static inline int page_cache_get_speculative(struct page *page)
{ {
VM_BUG_ON(in_interrupt()); VM_BUG_ON(in_interrupt());
#if !defined(CONFIG_SMP) && defined(CONFIG_TREE_RCU) #ifdef CONFIG_TINY_RCU
# ifdef CONFIG_PREEMPT_COUNT # ifdef CONFIG_PREEMPT_COUNT
VM_BUG_ON(!in_atomic()); VM_BUG_ON(!in_atomic());
# endif # endif