From: David Hildenbrand <david@xxxxxxxxxx> Subject: dax/kmem: use a single static memory group for a single probed unit Although dax/kmem users often disable auto-onlining and instead online memory manually (usually to ZONE_MOVABLE), there is still value in having auto-onlining be aware of the relationship of memory blocks. Let's treat one probed unit as a single static memory device, similar to a single ACPI memory device. Link: https://lkml.kernel.org/r/20210806124715.17090-7-david@xxxxxxxxxx Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Hui Zhu <teawater@xxxxxxxxx> Cc: Jason Wang <jasowang@xxxxxxxxxx> Cc: Len Brown <lenb@xxxxxxxxxx> Cc: Marek Kedzierski <mkedzier@xxxxxxxxxx> Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Mike Rapoport <rppt@xxxxxxxxxx> Cc: Oscar Salvador <osalvador@xxxxxxx> Cc: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx> Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx> Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx> Cc: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/dax/kmem.c | 40 ++++++++++++++++++++++++++++++++-------- 1 file changed, 32 insertions(+), 8 deletions(-) --- a/drivers/dax/kmem.c~dax-kmem-use-a-single-static-memory-group-for-a-single-probed-unit +++ a/drivers/dax/kmem.c @@ -37,15 +37,16 @@ static int dax_kmem_range(struct dev_dax struct dax_kmem_data { const char *res_name; + int mgid; struct resource *res[]; }; static int dev_dax_kmem_probe(struct dev_dax *dev_dax) { struct device *dev = &dev_dax->dev; + unsigned long total_len = 0; struct dax_kmem_data *data; - int rc = -ENOMEM; - int i, mapped = 0; + int i, rc, mapped = 0; int numa_node; /* @@ -61,24 +62,44 @@ static int dev_dax_kmem_probe(struct dev return -EINVAL; } + for (i = 0; i < dev_dax->nr_range; i++) { + struct range range; + + rc = dax_kmem_range(dev_dax, i, &range); + if (rc) { + dev_info(dev, "mapping%d: %#llx-%#llx too small after alignment\n", + i, range.start, range.end); + continue; + } + total_len += range_len(&range); + } + + if (!total_len) { + dev_warn(dev, "rejecting DAX region without any memory after alignment\n"); + return -EINVAL; + } + data = kzalloc(struct_size(data, res, dev_dax->nr_range), GFP_KERNEL); if (!data) return -ENOMEM; + rc = -ENOMEM; data->res_name = kstrdup(dev_name(dev), GFP_KERNEL); if (!data->res_name) goto err_res_name; + rc = memory_group_register_static(numa_node, total_len); + if (rc < 0) + goto err_reg_mgid; + data->mgid = rc; + for (i = 0; i < dev_dax->nr_range; i++) { struct resource *res; struct range range; rc = dax_kmem_range(dev_dax, i, &range); - if (rc) { - dev_info(dev, "mapping%d: %#llx-%#llx too small after alignment\n", - i, range.start, range.end); + if (rc) continue; - } /* Region is permanently reserved if hotremove fails. */ res = request_mem_region(range.start, range_len(&range), data->res_name); @@ -108,8 +129,8 @@ static int dev_dax_kmem_probe(struct dev * Ensure that future kexec'd kernels will not treat * this as RAM automatically. */ - rc = add_memory_driver_managed(numa_node, range.start, - range_len(&range), kmem_name, MHP_NONE); + rc = add_memory_driver_managed(data->mgid, range.start, + range_len(&range), kmem_name, MHP_NID_IS_MGID); if (rc) { dev_warn(dev, "mapping%d: %#llx-%#llx memory add failed\n", @@ -129,6 +150,8 @@ static int dev_dax_kmem_probe(struct dev return 0; err_request_mem: + memory_group_unregister(data->mgid); +err_reg_mgid: kfree(data->res_name); err_res_name: kfree(data); @@ -171,6 +194,7 @@ static void dev_dax_kmem_remove(struct d } if (success >= dev_dax->nr_range) { + memory_group_unregister(data->mgid); kfree(data->res_name); kfree(data); dev_set_drvdata(dev, NULL); _
