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[PATCH] x86-64: split remaining fake nodes equally

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Extends the numa=fake x86_64 command-line option to split the remaining
system memory into equal-sized nodes.

For example:
numa=fake=2*512,4*	gives two 512M nodes and the remaining system
			memory is split into four approximately equal
			chunks.

This is beneficial for systems where the exact size of RAM is unknown or not
necessarily relevant, but the granularity with which nodes shall be allocated
is known.

Cc: Andi Kleen <ak@suse.de>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
David Rientjes 2007-05-02 19:27:09 +02:00 committed by Andi Kleen
parent 8b8ca80e19
commit 14694d736b
2 changed files with 21 additions and 5 deletions
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4
Documentation/x86_64/boot-options.txt
View file

@ -155,7 +155,9 @@ NUMA
depending on the sizes and coefficients listed. For example:
numa=fake=2*512,1024,4*256
gives two 512M nodes, a 1024M node, and four 256M nodes. The
remaining system RAM is allocated to an additional node.
remaining system RAM is allocated to an additional node. If
the last character of CMDLINE is a *, the remaining system RAM
is instead divided up equally among its coefficient.
numa=hotadd=percent
Only allow hotadd memory to preallocate page structures upto

22
arch/x86_64/mm/numa.c
View file

@ -418,11 +418,25 @@ static int __init numa_emulation(unsigned long start_pfn, unsigned long end_pfn)
done:
if (!num_nodes)
return -1;
/* Fill remainder of system RAM with a final node, if appropriate. */
/* Fill remainder of system RAM, if appropriate. */
if (addr < max_addr) {
setup_node_range(num_nodes, nodes, &addr, max_addr - addr,
max_addr);
num_nodes++;
switch (*(cmdline - 1)) {
case '*':
/* Split remaining nodes into coeff chunks */
if (coeff <= 0)
break;
num_nodes += split_nodes_equally(nodes, &addr, max_addr,
num_nodes, coeff);
break;
case ',':
/* Do not allocate remaining system RAM */
break;
default:
/* Give one final node */
setup_node_range(num_nodes, nodes, &addr,
max_addr - addr, max_addr);
num_nodes++;
}
}
out:
memnode_shift = compute_hash_shift(nodes, num_nodes);