Previously, numa_off was set unconditionally in dummy_numa_init() even with a fake numa node. Then ACPI set node id as NUMA_NO_NODE(-1) after acpi_map_pxm_to_node() because it regards numa_off as turning off the numa node. Hence dev_dax->target_node is NUMA_NO_NODE on arm64 with fake numa.
Without this patch, pmem can't be probed as a RAM device on arm64 if SRAT table isn't present: $ndctl create-namespace -fe namespace0.0 --mode=devdax --map=dev -s 1g -a 64K kmem dax0.0: rejecting DAX region [mem 0x240400000-0x2bfffffff] with invalid node: -1 kmem: probe of dax0.0 failed with error -22 This fixes it by using fallback memory_add_physaddr_to_nid() as nid. Suggested-by: David Hildenbrand <[email protected]> Signed-off-by: Jia He <[email protected]> --- drivers/dax/kmem.c | 36 ++++++++++++++++++++---------------- 1 file changed, 20 insertions(+), 16 deletions(-) diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c index ac231cc36359..749674909e51 100644 --- a/drivers/dax/kmem.c +++ b/drivers/dax/kmem.c @@ -46,20 +46,7 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax) struct dax_kmem_data *data; int rc = -ENOMEM; int i, mapped = 0; - int numa_node; - - /* - * Ensure good NUMA information for the persistent memory. - * Without this check, there is a risk that slow memory - * could be mixed in a node with faster memory, causing - * unavoidable performance issues. - */ - numa_node = dev_dax->target_node; - if (numa_node < 0) { - dev_warn(dev, "rejecting DAX region with invalid node: %d\n", - numa_node); - return -EINVAL; - } + int numa_node = dev_dax->target_node, new_node; data = kzalloc(struct_size(data, res, dev_dax->nr_range), GFP_KERNEL); if (!data) @@ -104,6 +91,20 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax) */ res->flags = IORESOURCE_SYSTEM_RAM; + /* + * Ensure good NUMA information for the persistent memory. + * Without this check, there is a risk but not fatal that slow + * memory could be mixed in a node with faster memory, causing + * unavoidable performance issues. Furthermore, fallback node + * id can be used when numa_node is invalid. + */ + if (numa_node < 0) { + new_node = memory_add_physaddr_to_nid(range.start); + dev_info(dev, "changing nid from %d to %d for DAX region %pR\n", + numa_node, new_node, res); + numa_node = new_node; + } + /* * Ensure that future kexec'd kernels will not treat * this as RAM automatically. @@ -141,6 +142,7 @@ static void dev_dax_kmem_remove(struct dev_dax *dev_dax) int i, success = 0; struct device *dev = &dev_dax->dev; struct dax_kmem_data *data = dev_get_drvdata(dev); + int numa_node = dev_dax->target_node; /* * We have one shot for removing memory, if some memory blocks were not @@ -156,8 +158,10 @@ static void dev_dax_kmem_remove(struct dev_dax *dev_dax) if (rc) continue; - rc = remove_memory(dev_dax->target_node, range.start, - range_len(&range)); + if (numa_node < 0) + numa_node = memory_add_physaddr_to_nid(range.start); + + rc = remove_memory(numa_node, range.start, range_len(&range)); if (rc == 0) { release_resource(data->res[i]); kfree(data->res[i]); -- 2.17.1
