[PATCH 7/9] x86: make early_node_mem get mem > 4g if possible -v2

Yinghai Lu
2009-12-18T09:50:35Z

so we could put pgdata for the node high, and later sparse
vmmap will get the section nr that need.

with this patch will make <4g ram will not use sparse vmmap

before this patch, will get, before swiotlb try get bootmem
[ 0.000000] nid=1 start=0 end=2080000 aligned=1
[ 0.000000] free [10 - 96]
[ 0.000000] free [b12 - 1000]
[ 0.000000] free [359f - 38a3]
[ 0.000000] free [38b5 - 3a00]
[ 0.000000] free [41e01 - 42000]
[ 0.000000] free [73dde - 73e00]
[ 0.000000] free [73fdd - 74000]
[ 0.000000] free [741dd - 74200]
[ 0.000000] free [743dd - 74400]
[ 0.000000] free [745dd - 74600]
[ 0.000000] free [747dd - 74800]
[ 0.000000] free [749dd - 74a00]
[ 0.000000] free [74bdd - 74c00]
[ 0.000000] free [74ddd - 74e00]
[ 0.000000] free [74fdd - 75000]
[ 0.000000] free [751dd - 75200]
[ 0.000000] free [753dd - 75400]
[ 0.000000] free [755dd - 75600]
[ 0.000000] free [757dd - 75800]
[ 0.000000] free [759dd - 75a00]
[ 0.000000] free [75bdd - 7bf5f]
[ 0.000000] free [7f730 - 7f750]
[ 0.000000] free [100000 - 2080000]
[ 0.000000] total free 1f87170
[ 93.301474] Placing 64MB software IO TLB between ffff880075bdd000 - ffff880079bdd000
[ 93.311814] software IO TLB at phys 0x75bdd000 - 0x79bdd000

with this patch will get: before swiotlb try get bootmem
[ 0.000000] nid=1 start=0 end=2080000 aligned=1
[ 0.000000] free [a - 96]
[ 0.000000] free [702 - 1000]
[ 0.000000] free [359f - 3600]
[ 0.000000] free [37de - 3800]
[ 0.000000] free [39dd - 3a00]
[ 0.000000] free [3bdd - 3c00]
[ 0.000000] free [3ddd - 3e00]
[ 0.000000] free [3fdd - 4000]
[ 0.000000] free [41dd - 4200]
[ 0.000000] free [43dd - 4400]
[ 0.000000] free [45dd - 4600]
[ 0.000000] free [47dd - 4800]
[ 0.000000] free [49dd - 4a00]
[ 0.000000] free [4bdd - 4c00]
[ 0.000000] free [4ddd - 4e00]
[ 0.000000] free [4fdd - 5000]
[ 0.000000] free [51dd - 5200]
[ 0.000000] free [53dd - 5400]
[ 0.000000] free [55dd - 7bf5f]
[ 0.000000] free [7f730 - 7f750]
[ 0.000000] free [100428 - 100600]
[ 0.000000] free [13ea01 - 13ec00]
[ 0.000000] free [170800 - 2080000]
[ 0.000000] total free 1f87170

[ 92.689485] PCI-DMA: Using software bounce buffering for IO (SWIOTLB)
[ 92.699799] Placing 64MB software IO TLB between ffff8800055dd000 - ffff8800095dd000
[ 92.710916] software IO TLB at phys 0x55dd000 - 0x95dd000

so will get enough space below 4G, aka pfn 0x100000

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
arch/x86/mm/numa_64.c | 21 +++++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)

Index: linux-2.6/arch/x86/mm/numa_64.c
===================================================================
--- linux-2.6.orig/arch/x86/mm/numa_64.c
+++ linux-2.6/arch/x86/mm/numa_64.c
@@ -163,14 +163,27 @@ static void * __init early_node_mem(int
unsigned long end, unsigned long size,
unsigned long align)
{
- unsigned long mem = find_e820_area(start, end, size, align);
+ unsigned long mem;

+ /*
+ * put it on high as possible
+ * something will go with NODE_DATA
+ */
+ if (start < (MAX_DMA_PFN<<PAGE_SHIFT))
+ start = MAX_DMA_PFN<<PAGE_SHIFT;
+ if (start < (MAX_DMA32_PFN<<PAGE_SHIFT) &&
+ end > (MAX_DMA32_PFN<<PAGE_SHIFT))
+ start = MAX_DMA32_PFN<<PAGE_SHIFT;
+ mem = find_e820_area(start, end, size, align);
if (mem != -1L)
return __va(mem);

-
- start = __pa(MAX_DMA_ADDRESS);
- end = max_low_pfn_mapped << PAGE_SHIFT;
+ /* extend the search scope */
+ end = max_pfn_mapped << PAGE_SHIFT;
+ if (end > (MAX_DMA32_PFN<<PAGE_SHIFT))
+ start = MAX_DMA32_PFN<<PAGE_SHIFT;
+ else
+ start = MAX_DMA_PFN<<PAGE_SHIFT;
mem = find_e820_area(start, end, size, align);
if (mem != -1L)
return __va(mem);