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Commit ce003330 authored by Yinghai Lu's avatar Yinghai Lu Committed by Tejun Heo
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x86-64, NUMA: Fix distance table handling 



NUMA distance table handling has the following problems.

* numa_reset_distance() uses numa_distance * sizeof(numa_distance[0])
  as the table size when it should be using the square of
  numa_distance.

* The same size miscalculation when allocation space for phys_dist in
  numa_emulation().

* In numa_emulation(), phys_dist must be reserved; otherwise, the new
  emulated distance table may overlap it.

Fix them and, while at it, take numa_distance_cnt resetting in
numa_reset_distance() out of the if block to simplify the code a bit.

David Rientjes reported incorrect handling of distance table during
emulation.

-tj: Edited out numa_alloc_distance() related changes which weren't
     necessary and rewrote patch description.

-v2: Ingo was unhappy with 80-column limit induced linebreaks.  Let
     lines run over 80-column.

Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Reported-by: default avatarDavid Rientjes <rientjes@google.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
parent cc289894

arch/x86/mm/numa_64.c

+3 −5
Original line number Diff line number Diff line
@@ -390,14 +390,12 @@ static void __init numa_nodemask_from_meminfo(nodemask_t *nodemask, 
 */

void __init numa_reset_distance(void)

{

	size_t size;

	size_t size = numa_distance_cnt * numa_distance_cnt * sizeof(numa_distance[0]);



	if (numa_distance_cnt) {

		size = numa_distance_cnt * sizeof(numa_distance[0]);

	if (numa_distance_cnt)

		memblock_x86_free_range(__pa(numa_distance),

					__pa(numa_distance) + size);

	numa_distance_cnt = 0;

	}

	numa_distance = NULL;

}

arch/x86/mm/numa_emulation.c

+8 −6
Original line number Diff line number Diff line
@@ -300,6 +300,7 @@ void __init numa_emulation(struct numa_meminfo *numa_meminfo, int numa_dist_cnt) 
	static struct numa_meminfo pi __initdata;

	const u64 max_addr = max_pfn << PAGE_SHIFT;

	u8 *phys_dist = NULL;

	size_t phys_size = numa_dist_cnt * numa_dist_cnt * sizeof(phys_dist[0]);

	int i, j, ret;



	if (!emu_cmdline)
@@ -336,21 +337,18 @@ void __init numa_emulation(struct numa_meminfo *numa_meminfo, int numa_dist_cnt) 
		goto no_emu;

	}



	/*

	 * Copy the original distance table.  It's temporary so no need to

	 * reserve it.

	 */

	/* copy the physical distance table */

	if (numa_dist_cnt) {

		size_t size = numa_dist_cnt * sizeof(phys_dist[0]);

		u64 phys;



		phys = memblock_find_in_range(0,

					      (u64)max_pfn_mapped << PAGE_SHIFT,

					      size, PAGE_SIZE);

					      phys_size, PAGE_SIZE);

		if (phys == MEMBLOCK_ERROR) {

			pr_warning("NUMA: Warning: can't allocate copy of distance table, disabling emulation\n");

			goto no_emu;

		}

		memblock_x86_reserve_range(phys, phys + phys_size, "TMP NUMA DIST");

		phys_dist = __va(phys);



		for (i = 0; i < numa_dist_cnt; i++)
@@ -398,6 +396,10 @@ void __init numa_emulation(struct numa_meminfo *numa_meminfo, int numa_dist_cnt) 
			numa_set_distance(i, j, dist);

		}

	}



	/* free the copied physical distance table */

	if (phys_dist)

		memblock_x86_free_range(__pa(phys_dist), __pa(phys_dist) + phys_size);

	return;



no_emu: