From 8b8ca80e192b10eecc01fc44a2902510af86f73b Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Wed, 2 May 2007 19:27:09 +0200 Subject: [PATCH] x86-64: configurable fake numa node sizes Extends the numa=fake x86_64 command-line option to allow for configurable node sizes. These nodes can be used in conjunction with cpusets for coarse memory resource management. The old command-line option is still supported: numa=fake=32 gives 32 fake NUMA nodes, ignoring the NUMA setup of the actual machine. But now you may configure your system for the node sizes of your choice: numa=fake=2*512,1024,2*256 gives two 512M nodes, one 1024M node, two 256M nodes, and the rest of system memory to a sixth node. The existing hash function is maintained to support the various node sizes that are possible with this implementation. Each node of the same size receives roughly the same amount of available pages, regardless of any reserved memory with its address range. The total available pages on the system is calculated and divided by the number of equal nodes to allocate. These nodes are then dynamically allocated and their borders extended until such time as their number of available pages reaches the required size. Configurable node sizes are recommended when used in conjunction with cpusets for memory control because it eliminates the overhead associated with scanning the zonelists of many smaller full nodes on page_alloc(). Cc: Andi Kleen Signed-off-by: David Rientjes Signed-off-by: Andi Kleen Cc: Paul Jackson Cc: Christoph Lameter Signed-off-by: Andrew Morton --- Documentation/x86_64/boot-options.txt | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'Documentation/x86_64') diff --git a/Documentation/x86_64/boot-options.txt b/Documentation/x86_64/boot-options.txt index 85f51e5a749f..7500aad95f3c 100644 --- a/Documentation/x86_64/boot-options.txt +++ b/Documentation/x86_64/boot-options.txt @@ -149,7 +149,13 @@ NUMA numa=noacpi Don't parse the SRAT table for NUMA setup - numa=fake=X Fake X nodes and ignore NUMA setup of the actual machine. + numa=fake=CMDLINE + If a number, fakes CMDLINE nodes and ignores NUMA setup of the + actual machine. Otherwise, system memory is configured + 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. numa=hotadd=percent Only allow hotadd memory to preallocate page structures upto -- cgit v1.2.3-59-g8ed1b