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Commit ffd10a2b authored by Magnus Damm's avatar Magnus Damm Committed by Linus Torvalds
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[PATCH] x86_64: Make node boundaries consistent 



The current x86_64 NUMA memory code is inconsequent when it comes to node
memory ranges. The exact behaviour varies depending on which config option
that is used.

setup_node_bootmem() has start and end as arguments and these are used to
calculate the size of the node like this: (end - start). This is all fine
if end is pointing to the first non-available byte. The problem is that the
current x86_64 code sometimes treats it as the last present byte and sometimes
as the first non-available byte. The result is that some configurations might
lose a page at the end of the range.

This patch tries to fix CONFIG_ACPI_NUMA, CONFIG_K8_NUMA and CONFIG_NUMA_EMU
so they all treat the end variable as the first non-available byte. This is
the same way as the single node code.

The patch is boot tested on dual x86_64 hardware with the above configurations,
but maybe the removed code is needed as some workaround?

Signed-off-by: default avatarMagnus Damm <magnus@valinux.co.jp>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent e583538f

arch/x86_64/mm/k8topology.c

+1 −0
Original line number Diff line number Diff line
@@ -108,6 +108,7 @@ int __init k8_scan_nodes(unsigned long start, unsigned long end) 
		limit >>= 16; 

		limit <<= 24; 

		limit |= (1<<24)-1;

		limit++;



		if (limit > end_pfn << PAGE_SHIFT)

			limit = end_pfn << PAGE_SHIFT;

arch/x86_64/mm/numa.c

+0 −2
Original line number Diff line number Diff line
@@ -209,8 +209,6 @@ static int numa_emulation(unsigned long start_pfn, unsigned long end_pfn) 
 		if (i == numa_fake-1)

 			sz = (end_pfn<<PAGE_SHIFT) - nodes[i].start;

 		nodes[i].end = nodes[i].start + sz;

 		if (i != numa_fake-1)

 			nodes[i].end--;

 		printk(KERN_INFO "Faking node %d at %016Lx-%016Lx (%LuMB)\n",

 		       i,

 		       nodes[i].start, nodes[i].end,

arch/x86_64/mm/srat.c

+0 −4
Original line number Diff line number Diff line
@@ -71,8 +71,6 @@ static __init void cutoff_node(int i, unsigned long start, unsigned long end) 
			nd->start = nd->end;

	}

	if (nd->end > end) {

		if (!(end & 0xfff))

			end--;

		nd->end = end;

		if (nd->start > nd->end)

			nd->start = nd->end;
@@ -166,8 +164,6 @@ acpi_numa_memory_affinity_init(struct acpi_table_memory_affinity *ma) 
		if (nd->end < end)

			nd->end = end;

	}

	if (!(nd->end & 0xfff))

		nd->end--;

	printk(KERN_INFO "SRAT: Node %u PXM %u %Lx-%Lx\n", node, pxm,

	       nd->start, nd->end);

}