Messages in this thread |  | | | From | Johannes Weiner <> | | Subject | [RFC no patch yet] bootmem2: Another try | | Date | Wed, 07 May 2008 14:29:20 +0200 | |
Hi,
my idea is now as follows:
Bootmem2 is block-oriented where a block represents a contiguous range
of physical memory. Every block has a bitmap that keeps track of the
pages on it.
On top of this block interface, bootmem2 implements the node model
where a node can provide one or more memory blocks.
On configurations with multiple blocks per node, the arch code has to
register each block on its own.
free_bootmem and reserve_bootmem require that the requested range is
contiguous but they might go across node boundaries (two blocks on two
nodes can be contiguous). For example:
node 0: block 0 = 0-2G, block 1 = 4-6G
node 1: block 2 = 2-4G, block 3 = 6-8G
free_bootmem(1.5G, 3G) is valid here, the range spans two nodes and two
blocks but is contiguous.
free_bootmem_node and reserve_bootmem_node are more strict, the ranges
have to be completely within one block of the specified node (two
blocks on one node are never contiguous).
alloc_bootmem_node tries to get memory between goal and limit from a
specific node and falls back to any free memory range on that node on
failure.
alloc_bootmem tries to get memory from between goal and limit and
falls back to any free memory range in the system on failure.
What do you say?
Hannes
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