Commit fbe99959 authored by Tejun Heo's avatar Tejun Heo
Browse files

x86-64, NUMA: Prepare numa_emulation() for moving NUMA emulation into a separate file 



Update numa_emulation() such that, it

- takes @numa_meminfo and @numa_dist_cnt instead of directly
  referencing the global variables.

- copies the distance table by iterating each distance with
  node_distance() instead of memcpy'ing the distance table.

- tests emu_cmdline to determine whether emulation is requested and
  fills emu_nid_to_phys[] with identity mapping if emulation is not
  used.  This allows the caller to call numa_emulation()
  unconditionally and makes return value unncessary.

- defines dummy version if CONFIG_NUMA_EMU is disabled.

This patch doesn't introduce any behavior change.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
parent 69efcc6d

arch/x86/mm/numa_64.c

+33 −23
Original line number Diff line number Diff line
@@ -789,17 +789,20 @@ static int __init split_nodes_size_interleave(struct numa_meminfo *ei, 
 * Sets up the system RAM area from start_pfn to last_pfn according to the

 * numa=fake command-line option.

 */

static bool __init numa_emulation(void)

static void __init numa_emulation(struct numa_meminfo *numa_meminfo,

				  int numa_dist_cnt)

{

	static struct numa_meminfo ei __initdata;

	static struct numa_meminfo pi __initdata;

	const u64 max_addr = max_pfn << PAGE_SHIFT;

	int phys_dist_cnt = numa_distance_cnt;

	u8 *phys_dist = NULL;

	int i, j, ret;



	if (!emu_cmdline)

		goto no_emu;



	memset(&ei, 0, sizeof(ei));

	pi = numa_meminfo;

	pi = *numa_meminfo;



	for (i = 0; i < MAX_NUMNODES; i++)

		emu_nid_to_phys[i] = NUMA_NO_NODE;
@@ -822,19 +825,19 @@ static bool __init numa_emulation(void) 
	}



	if (ret < 0)

		return false;

		goto no_emu;



	if (numa_cleanup_meminfo(&ei) < 0) {

		pr_warning("NUMA: Warning: constructed meminfo invalid, disabling emulation\n");

		return false;

		goto no_emu;

	}



	/*

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

	 * reserve it.

	 */

	if (phys_dist_cnt) {

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

	if (numa_dist_cnt) {

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

		u64 phys;



		phys = memblock_find_in_range(0,
@@ -842,14 +845,18 @@ static bool __init numa_emulation(void) 
					      size, PAGE_SIZE);

		if (phys == MEMBLOCK_ERROR) {

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

			return false;

			goto no_emu;

		}

		phys_dist = __va(phys);

		memcpy(phys_dist, numa_distance, size);



		for (i = 0; i < numa_dist_cnt; i++)

			for (j = 0; j < numa_dist_cnt; j++)

				phys_dist[i * numa_dist_cnt + j] =

					node_distance(i, j);

	}



	/* commit */

	numa_meminfo = ei;

	*numa_meminfo = ei;



	/*

	 * Transform __apicid_to_node table to use emulated nids by
@@ -878,17 +885,26 @@ static bool __init numa_emulation(void) 
			int physj = emu_nid_to_phys[j];

			int dist;



			if (physi >= phys_dist_cnt || physj >= phys_dist_cnt)

			if (physi >= numa_dist_cnt || physj >= numa_dist_cnt)

				dist = physi == physj ?

					LOCAL_DISTANCE : REMOTE_DISTANCE;

			else

				dist = phys_dist[physi * phys_dist_cnt + physj];

				dist = phys_dist[physi * numa_dist_cnt + physj];



			numa_set_distance(i, j, dist);

		}

	}

	return true;

	return;



no_emu:

	/* No emulation.  Build identity emu_nid_to_phys[] for numa_add_cpu() */

	for (i = 0; i < ARRAY_SIZE(emu_nid_to_phys); i++)

		emu_nid_to_phys[i] = i;

}

#else	/* CONFIG_NUMA_EMU */

static inline void numa_emulation(struct numa_meminfo *numa_meminfo,

				  int numa_dist_cnt)

{ }

#endif	/* CONFIG_NUMA_EMU */



static int __init dummy_numa_init(void)
@@ -937,15 +953,9 @@ void __init initmem_init(void) 


		if (numa_cleanup_meminfo(&numa_meminfo) < 0)

			continue;

#ifdef CONFIG_NUMA_EMU

		/*

		 * If requested, try emulation.  If emulation is not used,

		 * build identity emu_nid_to_phys[] for numa_add_cpu()

		 */

		if (!emu_cmdline || !numa_emulation())

			for (j = 0; j < ARRAY_SIZE(emu_nid_to_phys); j++)

				emu_nid_to_phys[j] = j;

#endif



		numa_emulation(&numa_meminfo, numa_distance_cnt);



		if (numa_register_memblks(&numa_meminfo) < 0)

			continue;

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