The patch titled
Subject: mm/memory_hotplug: allow memmap on memory hotplug request to fallback
has been added to the -mm mm-unstable branch. Its filename is
mm-memory_hotplug-allow-memmap-on-memory-hotplug-request-to-fallback.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-memory_hotplug-allow-memmap-on-memory-hotplug-request-to-fallback.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
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
mm-hugepage-pud-allow-arch-specific-helper-function-to-check-huge-page-pud-support.patch
mm-hugepage-pud-allow-arch-specific-helper-function-to-check-huge-page-pud-support-fix.patch
mm-change-pudp_huge_get_and_clear_full-take-vm_area_struct-as-arg.patch
mm-vmemmap-improve-vmemmap_can_optimize-and-allow-architectures-to-override.patch
mm-vmemmap-allow-architectures-to-override-how-vmemmap-optimization-works.patch
mm-add-pud_same-similar-to-__have_arch_p4d_same.patch
mm-huge-pud-use-transparent-huge-pud-helpers-only-with-config_transparent_hugepage.patch
mm-vmemmap-optimization-split-hugetlb-and-devdax-vmemmap-optimization.patch
powerpc-mm-trace-convert-trace-event-to-trace-event-class.patch
powerpc-book3s64-mm-enable-transparent-pud-hugepage.patch
powerpc-book3s64-vmemmap-switch-radix-to-use-a-different-vmemmap-handling-function.patch
powerpc-book3s64-vmemmap-switch-radix-to-use-a-different-vmemmap-handling-function-fix.patch
powerpc-book3s64-vmemmap-switch-radix-to-use-a-different-vmemmap-handling-function-fix-2.patch
powerpc-book3s64-radix-add-support-for-vmemmap-optimization-for-radix.patch
powerpc-book3s64-radix-add-support-for-vmemmap-optimization-for-radix-fix.patch
powerpc-book3s64-radix-remove-mmu_vmemmap_psize.patch
powerpc-book3s64-radix-remove-mmu_vmemmap_psize-fix.patch
powerpc-book3s64-radix-add-debug-message-to-give-more-details-of-vmemmap-allocation.patch
mm-memory_hotplug-simplify-arch_mhp_memmap_on_memory_enable-kconfig.patch
mm-memory_hotplug-allow-memmap-on-memory-hotplug-request-to-fallback.patch
mm-memory_hotplug-allow-architecture-to-override-memmap-on-memory-support-check.patch
mm-memory_hotplug-support-memmap_on_memory-when-memmap-is-not-aligned-to-pageblocks.patch
powerpc-book3s64-memhotplug-enable-memmap-on-memory-for-radix.patch
mm-memory_hotplug-embed-vmem_altmap-details-in-memory-block.patch
