From ee408c79420b6a437332d6977fe33ab72c36dc97 Mon Sep 17 00:00:00 2001
From: Andi Kleen <ak@suse.de>
Date: Mon, 16 Jan 2006 01:56:51 +0100
Subject: [PATCH] [PATCH] x86_64: Don't try to put kernel page tables beyond
ZONE_DMA32.
For not fully explained reasons it broke mem=... on several setups.
Also minor cleanup.
Cc: axboe@suse.de
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
arch/x86_64/mm/init.c | 18 +++++-------------
1 file changed, 5 insertions(+), 13 deletions(-)
diff --git a/arch/x86_64/mm/init.c b/arch/x86_64/mm/init.c
index eca60125efc3..ef84106c1509 100644
--- a/arch/x86_64/mm/init.c
+++ b/arch/x86_64/mm/init.c
@@ -262,19 +262,11 @@ static void __init find_early_table_space(unsigned long end)
tables = round_up(puds * sizeof(pud_t), PAGE_SIZE) +
round_up(pmds * sizeof(pmd_t), PAGE_SIZE);
- /* Put page tables beyond the DMA zones if possible.
- RED-PEN might be better to spread them out more over
- memory to avoid hotspots */
- if (end > MAX_DMA32_PFN<<PAGE_SHIFT)
- start = MAX_DMA32_PFN << PAGE_SHIFT;
- else if (end > MAX_DMA_PFN << PAGE_SHIFT)
- start = MAX_DMA_PFN << PAGE_SHIFT;
- else
- start = 0x8000;
-
- table_start = find_e820_area(start, end, tables);
- if (table_start == -1)
- table_start = find_e820_area(0x8000, end, tables);
+ /* RED-PEN putting page tables only on node 0 could
+ cause a hotspot and fill up ZONE_DMA. The page tables
+ need roughly 0.5KB per GB. */
+ start = 0x8000;
+ table_start = find_e820_area(start, end, tables);
if (table_start == -1UL)
panic("Cannot find space for the kernel page tables");
--
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