Commit 5d30f92e authored by Dan Williams's avatar Dan Williams
Browse files

x86/NUMA: Provide a range-to-target_node lookup facility 



The DEV_DAX_KMEM facility is a generic mechanism to allow device-dax
instances, fronting performance-differentiated-memory like pmem, to be
added to the System RAM pool. The NUMA node for that hot-added memory is
derived from the device-dax instance's 'target_node' attribute.

Recall that the 'target_node' is the ACPI-PXM-to-node translation for
memory when it comes online whereas the 'numa_node' attribute of the
device represents the closest online cpu node.

Presently useful target_node information from the ACPI SRAT is discarded
with the expectation that "Reserved" memory will never be onlined. Now,
DEV_DAX_KMEM violates that assumption, there is a need to retain the
translation. Move, rather than discard, numa_memblk data to a secondary
array that memory_add_physaddr_to_target_node() may consider at a later
point in time.

Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <x86@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Reported-by: default avatarkbuild test robot <lkp@intel.com>
Reviewed-by: default avatarIngo Molnar <mingo@kernel.org>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/158188326978.894464.217282995221175417.stgit@dwillia2-desk3.amr.corp.intel.com
parent 1e5d8e1e

arch/x86/mm/numa.c

+51 −10
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ struct pglist_data *node_data[MAX_NUMNODES] __read_mostly; 
EXPORT_SYMBOL(node_data);



static struct numa_meminfo numa_meminfo __initdata_or_meminfo;

static struct numa_meminfo numa_reserved_meminfo __initdata_or_meminfo;



static int numa_distance_cnt;

static u8 *numa_distance;
@@ -164,6 +165,19 @@ void __init numa_remove_memblk_from(int idx, struct numa_meminfo *mi) 
		(mi->nr_blks - idx) * sizeof(mi->blk[0]));

}



/**

 * numa_move_tail_memblk - Move a numa_memblk from one numa_meminfo to another

 * @dst: numa_meminfo to append block to

 * @idx: Index of memblk to remove

 * @src: numa_meminfo to remove memblk from

 */

static void __init numa_move_tail_memblk(struct numa_meminfo *dst, int idx,

					 struct numa_meminfo *src)

{

	dst->blk[dst->nr_blks++] = src->blk[idx];

	numa_remove_memblk_from(idx, src);

}



/**

 * numa_add_memblk - Add one numa_memblk to numa_meminfo

 * @nid: NUMA node ID of the new memblk
@@ -233,14 +247,19 @@ int __init numa_cleanup_meminfo(struct numa_meminfo *mi) 
	for (i = 0; i < mi->nr_blks; i++) {

		struct numa_memblk *bi = &mi->blk[i];



		/* make sure all blocks are inside the limits */

		/* move / save reserved memory ranges */

		if (!memblock_overlaps_region(&memblock.memory,

					bi->start, bi->end - bi->start)) {

			numa_move_tail_memblk(&numa_reserved_meminfo, i--, mi);

			continue;

		}



		/* make sure all non-reserved blocks are inside the limits */

		bi->start = max(bi->start, low);

		bi->end = min(bi->end, high);



		/* and there's no empty or non-exist block */

		if (bi->start >= bi->end ||

		    !memblock_overlaps_region(&memblock.memory,

			bi->start, bi->end - bi->start))

		/* and there's no empty block */

		if (bi->start >= bi->end)

			numa_remove_memblk_from(i--, mi);

	}
@@ -877,16 +896,38 @@ EXPORT_SYMBOL(cpumask_of_node); 


#endif	/* !CONFIG_DEBUG_PER_CPU_MAPS */



#ifdef CONFIG_MEMORY_HOTPLUG

int memory_add_physaddr_to_nid(u64 start)

#ifdef CONFIG_NUMA_KEEP_MEMINFO

static int meminfo_to_nid(struct numa_meminfo *mi, u64 start)

{

	struct numa_meminfo *mi = &numa_meminfo;

	int nid = mi->blk[0].nid;

	int i;



	for (i = 0; i < mi->nr_blks; i++)

		if (mi->blk[i].start <= start && mi->blk[i].end > start)

			nid = mi->blk[i].nid;

			return mi->blk[i].nid;

	return NUMA_NO_NODE;

}



int phys_to_target_node(phys_addr_t start)

{

	int nid = meminfo_to_nid(&numa_meminfo, start);



	/*

	 * Prefer online nodes, but if reserved memory might be

	 * hot-added continue the search with reserved ranges.

	 */

	if (nid != NUMA_NO_NODE)

		return nid;



	return meminfo_to_nid(&numa_reserved_meminfo, start);

}

EXPORT_SYMBOL_GPL(phys_to_target_node);



int memory_add_physaddr_to_nid(u64 start)

{

	int nid = meminfo_to_nid(&numa_meminfo, start);



	if (nid == NUMA_NO_NODE)

		nid = numa_meminfo.blk[0].nid;

	return nid;

}

EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);

include/linux/numa.h

+13 −1
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef _LINUX_NUMA_H

#define _LINUX_NUMA_H



#include <linux/types.h>



#ifdef CONFIG_NODES_SHIFT

#define NODES_SHIFT     CONFIG_NODES_SHIFT
@@ -21,12 +21,24 @@ 
#endif



#ifdef CONFIG_NUMA

/* Generic implementation available */

int numa_map_to_online_node(int node);



/*

 * Optional architecture specific implementation, users need a "depends

 * on $ARCH"

 */

int phys_to_target_node(phys_addr_t addr);

#else

static inline int numa_map_to_online_node(int node)

{

	return NUMA_NO_NODE;

}



static inline int phys_to_target_node(phys_addr_t addr)

{

	return NUMA_NO_NODE;

}

#endif



#endif /* _LINUX_NUMA_H */

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