alistair23-linux/drivers/nvdimm/e820.c
Dan Williams 7b27a8622f libnvdimm/e820: Retrieve and populate correct 'target_node' info
Use the new phys_to_target_node() and numa_map_to_online_node() helpers
to retrieve the correct id for the 'numa_node' ("local" / online
initiator node) and 'target_node' (offline target memory node) sysfs
attributes.

Below is an example from a 4 NUMA node system where all the memory on
node2 is pmem / reserved. It should be noted that with the arrival of
the ACPI HMAT table and EFI Specific Purpose Memory the kernel will
start to see more platforms with reserved / performance differentiated
memory in its own NUMA node. Hence all the stakeholders on the Cc for
what is ostensibly a libnvdimm local patch.

=== Before ===

/* Notice no online memory on node2 at start */

# numactl --hardware
available: 3 nodes (0-1,3)
node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
node 0 size: 3958 MB
node 0 free: 3708 MB
node 1 cpus: 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39
node 1 size: 4027 MB
node 1 free: 3871 MB
node 3 cpus:
node 3 size: 3994 MB
node 3 free: 3971 MB
node distances:
node   0   1   3
  0:  10  21  21
  1:  21  10  21
  3:  21  21  10

/*
 * Put the pmem namespace into devdax mode so it can be assigned to the
 * kmem driver
 */

# ndctl create-namespace -e namespace0.0 -m devdax -f
{
  "dev":"namespace0.0",
  "mode":"devdax",
  "map":"dev",
  "size":"3.94 GiB (4.23 GB)",
  "uuid":"1650af9b-9ba3-4704-acd6-10178399d9a3",
  [..]
}

/* Online Persistent Memory as System RAM */

# daxctl reconfigure-device --mode=system-ram dax0.0
libdaxctl: memblock_in_dev: dax0.0: memory0: Unable to determine phys_index: Success
libdaxctl: memblock_in_dev: dax0.0: memory0: Unable to determine phys_index: Success
libdaxctl: memblock_in_dev: dax0.0: memory0: Unable to determine phys_index: Success
libdaxctl: memblock_in_dev: dax0.0: memory0: Unable to determine phys_index: Success
[
  {
    "chardev":"dax0.0",
    "size":4225761280,
    "target_node":0,
    "mode":"system-ram"
  }
]
reconfigured 1 device

/* Note that the memory is onlined by default to the wrong node, node0 */

# numactl --hardware
available: 3 nodes (0-1,3)
node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
node 0 size: 7926 MB
node 0 free: 7655 MB
node 1 cpus: 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39
node 1 size: 4027 MB
node 1 free: 3871 MB
node 3 cpus:
node 3 size: 3994 MB
node 3 free: 3971 MB
node distances:
node   0   1   3
  0:  10  21  21
  1:  21  10  21
  3:  21  21  10

=== After ===

/* Notice that the "phys_index" error messages are gone */

# daxctl reconfigure-device --mode=system-ram dax0.0
[
  {
    "chardev":"dax0.0",
    "size":4225761280,
    "target_node":2,
    "mode":"system-ram"
  }
]
reconfigured 1 device

/* Notice that node2 is now correctly populated */

# numactl --hardware
available: 4 nodes (0-3)
node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
node 0 size: 3958 MB
node 0 free: 3793 MB
node 1 cpus: 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39
node 1 size: 4027 MB
node 1 free: 3851 MB
node 2 cpus:
node 2 size: 3968 MB
node 2 free: 3968 MB
node 3 cpus:
node 3 size: 3994 MB
node 3 free: 3908 MB
node distances:
node   0   1   2   3
  0:  10  21  21  21
  1:  21  10  21  21
  2:  21  21  10  21
  3:  21  21  21  10

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: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/158188327614.894464.13122730362187722603.stgit@dwillia2-desk3.amr.corp.intel.com
2020-02-18 10:28:05 -08:00

74 lines
1.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2015, Christoph Hellwig.
* Copyright (c) 2015, Intel Corporation.
*/
#include <linux/platform_device.h>
#include <linux/memory_hotplug.h>
#include <linux/libnvdimm.h>
#include <linux/module.h>
#include <linux/numa.h>
static int e820_pmem_remove(struct platform_device *pdev)
{
struct nvdimm_bus *nvdimm_bus = platform_get_drvdata(pdev);
nvdimm_bus_unregister(nvdimm_bus);
return 0;
}
static int e820_register_one(struct resource *res, void *data)
{
struct nd_region_desc ndr_desc;
struct nvdimm_bus *nvdimm_bus = data;
int nid = phys_to_target_node(res->start);
memset(&ndr_desc, 0, sizeof(ndr_desc));
ndr_desc.res = res;
ndr_desc.numa_node = numa_map_to_online_node(nid);
ndr_desc.target_node = nid;
set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
if (!nvdimm_pmem_region_create(nvdimm_bus, &ndr_desc))
return -ENXIO;
return 0;
}
static int e820_pmem_probe(struct platform_device *pdev)
{
static struct nvdimm_bus_descriptor nd_desc;
struct device *dev = &pdev->dev;
struct nvdimm_bus *nvdimm_bus;
int rc = -ENXIO;
nd_desc.provider_name = "e820";
nd_desc.module = THIS_MODULE;
nvdimm_bus = nvdimm_bus_register(dev, &nd_desc);
if (!nvdimm_bus)
goto err;
platform_set_drvdata(pdev, nvdimm_bus);
rc = walk_iomem_res_desc(IORES_DESC_PERSISTENT_MEMORY_LEGACY,
IORESOURCE_MEM, 0, -1, nvdimm_bus, e820_register_one);
if (rc)
goto err;
return 0;
err:
nvdimm_bus_unregister(nvdimm_bus);
dev_err(dev, "failed to register legacy persistent memory ranges\n");
return rc;
}
static struct platform_driver e820_pmem_driver = {
.probe = e820_pmem_probe,
.remove = e820_pmem_remove,
.driver = {
.name = "e820_pmem",
},
};
module_platform_driver(e820_pmem_driver);
MODULE_ALIAS("platform:e820_pmem*");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Intel Corporation");