The quilt patch titled Subject: mm/memory_hotplug: allow memmap on memory hotplug request to fallback has been removed from the -mm tree. Its filename was mm-memory_hotplug-allow-memmap-on-memory-hotplug-request-to-fallback.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx> Subject: mm/memory_hotplug: allow memmap on memory hotplug request to fallback Date: Tue, 8 Aug 2023 14:44:57 +0530 If not supported, fallback to not using memap on memmory. This avoids the need for callers to do the fallback. Link: https://lkml.kernel.org/r/20230808091501.287660-3-aneesh.kumar@xxxxxxxxxxxxx Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Acked-by: David Hildenbrand <david@xxxxxxxxxx> Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Nicholas Piggin <npiggin@xxxxxxxxx> Cc: Oscar Salvador <osalvador@xxxxxxx> Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/acpi/acpi_memhotplug.c | 3 +-- include/linux/memory_hotplug.h | 3 ++- mm/memory_hotplug.c | 13 ++++++------- 3 files changed, 9 insertions(+), 10 deletions(-) --- a/drivers/acpi/acpi_memhotplug.c~mm-memory_hotplug-allow-memmap-on-memory-hotplug-request-to-fallback +++ a/drivers/acpi/acpi_memhotplug.c @@ -211,8 +211,7 @@ static int acpi_memory_enable_device(str if (!info->length) continue; - if (mhp_supports_memmap_on_memory(info->length)) - mhp_flags |= MHP_MEMMAP_ON_MEMORY; + mhp_flags |= MHP_MEMMAP_ON_MEMORY; result = __add_memory(mgid, info->start_addr, info->length, mhp_flags); --- a/include/linux/memory_hotplug.h~mm-memory_hotplug-allow-memmap-on-memory-hotplug-request-to-fallback +++ a/include/linux/memory_hotplug.h @@ -97,6 +97,8 @@ typedef int __bitwise mhp_t; * To do so, we will use the beginning of the hot-added range to build * the page tables for the memmap array that describes the entire range. * Only selected architectures support it with SPARSE_VMEMMAP. + * This is only a hint, the core kernel can decide to not do this based on + * different alignment checks. */ #define MHP_MEMMAP_ON_MEMORY ((__force mhp_t)BIT(1)) /* @@ -354,7 +356,6 @@ extern struct zone *zone_for_pfn_range(i extern int arch_create_linear_mapping(int nid, u64 start, u64 size, struct mhp_params *params); void arch_remove_linear_mapping(u64 start, u64 size); -extern bool mhp_supports_memmap_on_memory(unsigned long size); #endif /* CONFIG_MEMORY_HOTPLUG */ #endif /* __LINUX_MEMORY_HOTPLUG_H */ --- a/mm/memory_hotplug.c~mm-memory_hotplug-allow-memmap-on-memory-hotplug-request-to-fallback +++ a/mm/memory_hotplug.c @@ -1247,7 +1247,7 @@ static int online_memory_block(struct me return device_online(&mem->dev); } -bool mhp_supports_memmap_on_memory(unsigned long size) +static bool mhp_supports_memmap_on_memory(unsigned long size) { unsigned long nr_vmemmap_pages = size / PAGE_SIZE; unsigned long vmemmap_size = nr_vmemmap_pages * sizeof(struct page); @@ -1339,13 +1339,12 @@ int __ref add_memory_resource(int nid, s * Self hosted memmap array */ if (mhp_flags & MHP_MEMMAP_ON_MEMORY) { - if (!mhp_supports_memmap_on_memory(size)) { - ret = -EINVAL; - goto error; + if (mhp_supports_memmap_on_memory(size)) { + mhp_altmap.free = PHYS_PFN(size); + mhp_altmap.base_pfn = PHYS_PFN(start); + params.altmap = &mhp_altmap; } - mhp_altmap.free = PHYS_PFN(size); - mhp_altmap.base_pfn = PHYS_PFN(start); - params.altmap = &mhp_altmap; + /* fallback to not using altmap */ } /* call arch's memory hotadd */ _ Patches currently in -mm which might be from aneesh.kumar@xxxxxxxxxxxxx are