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8dcd1448e7
Currently the heap has a fixed housekeeping factor of 16, which means 1/16 of the heap is reserved for list nodes. But this is not enough when there are many small allocations; in the worst case, 1/3 of the heap is needed for list nodes (32 byte heap_node for each 64 byte allocation). This has caused allocation failures on some platforms. Let's avoid trying to guess the best ratio. Instead, allocate more nodes as needed. To avoid recursion, the nodes are permanent allocations. So to minimize fragmentation, allocate them in small batches from the end of the last free space node. Bootstrap the free space list by embedding one node in the heap control struct. Some error paths are avoided because the nodes are allocated up front. Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org> Tested-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/r/20250617032306.1494528-3-samuel.holland@sifive.com Signed-off-by: Anup Patel <anup@brainfault.org>