mm-memory-rt.patch

From 7024768ab4465901c2ee847d451809028ef03889 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Fri, 3 Jul 2009 08:30:13 -0500
Subject: [PATCH] mm-memory-rt

commit 8a56ce758d645882ffbc920efd1d409c4ff83641 in tip.

On RT this is not a critical code path. It's preemptible so we go for
the PREEMPT=n case as well.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 mm/memory.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 833952d..90f674e 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1062,10 +1062,13 @@ static unsigned long unmap_page_range(struct mmu_gather *tlb,
 	return addr;
 }
 
-#ifdef CONFIG_PREEMPT
+#if defined(CONFIG_PREEMPT) && !defined(CONFIG_PREEMPT_RT)
 # define ZAP_BLOCK_SIZE	(8 * PAGE_SIZE)
 #else
-/* No preempt: go for improved straight-line efficiency */
+/*
+ * No preempt: go for improved straight-line efficiency
+ * on PREEMPT_RT this is not a critical latency-path.
+ */
 # define ZAP_BLOCK_SIZE	(1024 * PAGE_SIZE)
 #endif
 
-- 
1.7.0.4