Move xen patchset to new version's subdir.

[people/pmueller/ipfire-2.x.git] / src / patches / suse-2.6.27.31 / patches.suse / unmap_vmas-lat

diff --git a/src/patches/suse-2.6.27.31/patches.suse/unmap_vmas-lat b/src/patches/suse-2.6.27.31/patches.suse/unmap_vmas-lat
new file mode 100644 (file)
index 0000000..532f1ff
--- /dev/null
+++ b/src/patches/suse-2.6.27.31/patches.suse/unmap_vmas-lat
@@ -0,0 +1,32 @@
+From: andrea@suse.de
+Subject: low-latency stuff
+
+
+My point is that preempt and no-preempt should do the same thing there,
+otherwise when you benchmark -preempt, you'll get better latency,
+but not because of the preempt feature, but just because of unrelated
+latency improvements that have nothing to do with preempt.
+
+
+---
+ mm/memory.c |    8 ++++----
+ 1 file changed, 4 insertions(+), 4 deletions(-)
+
+--- a/mm/memory.c
++++ b/mm/memory.c
+@@ -855,11 +855,11 @@ static unsigned long unmap_page_range(st
+       return addr;
+ }
+ 
+-#ifdef CONFIG_PREEMPT
+-# define ZAP_BLOCK_SIZE       (8 * PAGE_SIZE)
++#ifdef CONFIG_SMP
++/* zap one pte page at a time */
++#define ZAP_BLOCK_SIZE                (FREE_PTE_NR * PAGE_SIZE)
+ #else
+-/* No preempt: go for improved straight-line efficiency */
+-# define ZAP_BLOCK_SIZE       (1024 * PAGE_SIZE)
++#define ZAP_BLOCK_SIZE                (253 * PAGE_SIZE)
+ #endif
+ 
+ /**