Commit cd429ce2 authored Feb 16, 2017 by Pavel Tatashin Committed by David S. Miller Feb 23, 2017

sparc64: memblock resizes are not handled properly

In add_node_ranges() when memblock resize happens, the iterator keeps using
the previous freed array. This bug cause hangs on machine where there are
over 128 memory blocks during boot. For example, on machines where memory
interleaving is small.
The problem is seen on T4-4 because it cant have 2T of memory, and memory
is interleaved at 8G. So we have 2T/8G = 256 regions to set node IDs. The
starting size of regions array is 128. Thus, we have to double at least one
time (actually we have to double twice because some memory is already
reserved and thus we need more than 256 regions). We start using an
incorrect pointer to the array after the first doubling.

Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Babu Moger <babu.moger@oracle.com>
Reviewed-by: Babu Moger <babu.moger@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 1537b26d

arch/sparc/mm/init_64.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -1126,6 +1126,10 @@ int of_node_to_nid(struct device_node *dp)
		static void __init add_node_ranges(void)
		{
		struct memblock_region *reg;
		unsigned long prev_max;

		memblock_resized:
		prev_max = memblock.memory.max;

		for_each_memblock(memory, reg) {
		unsigned long size = reg->size;
		@@ -1145,6 +1149,8 @@ static void __init add_node_ranges(void)

		memblock_set_node(start, this_end - start,
		&memblock.memory, nid);
		if (memblock.memory.max != prev_max)
		goto memblock_resized;
		start = this_end;
		}
		}

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