qubes-linux-kernel/patches.suse/unmap_vmas-lat
2011-04-19 22:09:59 +02:00

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From: andrea@suse.de
Subject: low-latency stuff
Patch-mainline: not yet
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
@@ -1060,11 +1060,11 @@ 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
/**