From 3bbc54dd1b62f1a4b218c70aafbeceeba7c90c5d Mon Sep 17 00:00:00 2001 From: Muchun Song Date: Tue, 28 Apr 2026 16:18:52 +0800 Subject: mm/sparse-vmemmap: pass @pgmap argument to memory deactivation paths Currently, the memory hot-remove call chain -- arch_remove_memory(), __remove_pages(), sparse_remove_section() and section_deactivate() -- does not carry the struct dev_pagemap pointer. This prevents the lower levels from knowing whether the section was originally populated with vmemmap optimizations (e.g., DAX with vmemmap optimization enabled). Without this information, we cannot call vmemmap_can_optimize() to determine if the vmemmap pages were optimized. As a result, the vmemmap page accounting during teardown will mistakenly assume a non-optimized allocation, leading to incorrect memmap statistics. To lay the groundwork for fixing the vmemmap page accounting, we need to pass the @pgmap pointer down to the deactivation location. Plumb the @pgmap argument through the APIs of arch_remove_memory(), __remove_pages() and sparse_remove_section(), mirroring the corresponding *_activate() paths. Link: https://lore.kernel.org/20260428081855.1249045-4-songmuchun@bytedance.com Signed-off-by: Muchun Song Acked-by: Mike Rapoport (Microsoft) Reviewed-by: Oscar Salvador Acked-by: David Hildenbrand (Arm) Acked-by: Liam R. Howlett Cc: "Aneesh Kumar K.V" Cc: Joao Martins Cc: Lorenzo Stoakes Cc: Madhavan Srinivasan Cc: Michael Ellerman Cc: Michal Hocko Cc: Nicholas Piggin Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- include/linux/memory_hotplug.h | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'include/linux/memory_hotplug.h') diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 815e908c4135..7c9d66729c60 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -135,9 +135,10 @@ static inline bool movable_node_is_enabled(void) return movable_node_enabled; } -extern void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap); +extern void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap, + struct dev_pagemap *pgmap); extern void __remove_pages(unsigned long start_pfn, unsigned long nr_pages, - struct vmem_altmap *altmap); + struct vmem_altmap *altmap, struct dev_pagemap *pgmap); /* reasonably generic interface to expand the physical pages */ extern int __add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages, @@ -307,7 +308,8 @@ extern int sparse_add_section(int nid, unsigned long pfn, unsigned long nr_pages, struct vmem_altmap *altmap, struct dev_pagemap *pgmap); extern void sparse_remove_section(unsigned long pfn, unsigned long nr_pages, - struct vmem_altmap *altmap); + struct vmem_altmap *altmap, + struct dev_pagemap *pgmap); extern struct zone *zone_for_pfn_range(enum mmop online_type, int nid, struct memory_group *group, unsigned long start_pfn, unsigned long nr_pages); -- cgit v1.2.3