From: David Rientjes 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 Signed-off-by: David Rientjes Cc: Paul Jackson Cc: Christoph Lameter Signed-off-by: Andrew Morton --- Documentation/x86_64/boot-options.txt | 4 +++- arch/x86_64/mm/numa.c | 22 ++++++++++++++++++---- 2 files changed, 21 insertions(+), 5 deletions(-) diff -puN Documentation/x86_64/boot-options.txt~x86_64-split-remaining-fake-nodes-equally Documentation/x86_64/boot-options.txt --- a/Documentation/x86_64/boot-options.txt~x86_64-split-remaining-fake-nodes-equally +++ a/Documentation/x86_64/boot-options.txt @@ -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 diff -puN arch/x86_64/mm/numa.c~x86_64-split-remaining-fake-nodes-equally arch/x86_64/mm/numa.c --- a/arch/x86_64/mm/numa.c~x86_64-split-remaining-fake-nodes-equally +++ a/arch/x86_64/mm/numa.c @@ -418,11 +418,25 @@ static int __init numa_emulation(unsigne 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); _