From: "David Hildenbrand (Arm)" <david@kernel.org>
To: linux-kernel@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>,
Oscar Salvador <osalvador@suse.de>,
Axel Rasmussen <axelrasmussen@google.com>,
Yuanchu Xie <yuanchu@google.com>, Wei Xu <weixugc@google.com>,
Lorenzo Stoakes <ljs@kernel.org>,
"Liam R. Howlett" <Liam.Howlett@oracle.com>,
Vlastimil Babka <vbabka@kernel.org>,
Mike Rapoport <rppt@kernel.org>,
Suren Baghdasaryan <surenb@google.com>,
Michal Hocko <mhocko@suse.com>,
Sidhartha Kumar <sidhartha.kumar@oracle.com>,
linux-mm@kvack.org, linux-cxl@vger.kernel.org,
linux-riscv@lists.infradead.org,
"David Hildenbrand (Arm)" <david@kernel.org>
Subject: [PATCH v2 09/15] mm/sparse: remove sparse_decode_mem_map()
Date: Fri, 20 Mar 2026 23:13:41 +0100 [thread overview]
Message-ID: <20260320-sparsemem_cleanups-v2-9-096addc8800d@kernel.org> (raw)
In-Reply-To: <20260320-sparsemem_cleanups-v2-0-096addc8800d@kernel.org>
section_deactivate() applies to CONFIG_SPARSEMEM_VMEMMAP only. So we can
just use pfn_to_page() (after making sure we have the start PFN of the
section), and remove sparse_decode_mem_map().
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
---
include/linux/memory_hotplug.h | 2 --
mm/sparse.c | 16 +---------------
2 files changed, 1 insertion(+), 17 deletions(-)
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index e77ef3d7ff73..815e908c4135 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -308,8 +308,6 @@ extern int sparse_add_section(int nid, unsigned long pfn,
struct dev_pagemap *pgmap);
extern void sparse_remove_section(unsigned long pfn, unsigned long nr_pages,
struct vmem_altmap *altmap);
-extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map,
- unsigned long pnum);
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);
diff --git a/mm/sparse.c b/mm/sparse.c
index 875f718a4c79..b5825c9ee2f2 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -274,18 +274,6 @@ static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long p
return coded_mem_map;
}
-#ifdef CONFIG_MEMORY_HOTPLUG
-/*
- * Decode mem_map from the coded memmap
- */
-struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum)
-{
- /* mask off the extra low bits of information */
- coded_mem_map &= SECTION_MAP_MASK;
- return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum);
-}
-#endif /* CONFIG_MEMORY_HOTPLUG */
-
static void __meminit sparse_init_one_section(struct mem_section *ms,
unsigned long pnum, struct page *mem_map,
struct mem_section_usage *usage, unsigned long flags)
@@ -754,8 +742,6 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
empty = is_subsection_map_empty(ms);
if (empty) {
- unsigned long section_nr = pfn_to_section_nr(pfn);
-
/*
* Mark the section invalid so that valid_section()
* return false. This prevents code from dereferencing
@@ -774,7 +760,7 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
kfree_rcu(ms->usage, rcu);
WRITE_ONCE(ms->usage, NULL);
}
- memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
+ memmap = pfn_to_page(SECTION_ALIGN_DOWN(pfn));
}
/*
--
2.43.0
next prev parent reply other threads:[~2026-03-20 22:14 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-20 22:13 [PATCH v2 00/15] mm: memory hot(un)plug and SPARSEMEM cleanups David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 01/15] mm/memory_hotplug: fix possible race in scan_movable_pages() David Hildenbrand (Arm)
2026-03-23 13:26 ` Lorenzo Stoakes (Oracle)
2026-03-23 13:40 ` David Hildenbrand (Arm)
2026-03-23 14:00 ` Lorenzo Stoakes (Oracle)
2026-03-20 22:13 ` [PATCH v2 02/15] mm/memory_hotplug: remove for_each_valid_pfn() usage David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 03/15] mm/sparse: remove WARN_ONs from (online|offline)_mem_sections() David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 04/15] mm/Kconfig: make CONFIG_MEMORY_HOTPLUG depend on CONFIG_SPARSEMEM_VMEMMAP David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 05/15] mm/memory_hotplug: simplify check_pfn_span() David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 06/15] mm/sparse: remove !CONFIG_SPARSEMEM_VMEMMAP leftovers for CONFIG_MEMORY_HOTPLUG David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 07/15] mm/bootmem_info: remove handling for !CONFIG_SPARSEMEM_VMEMMAP David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 08/15] mm/bootmem_info: avoid using sparse_decode_mem_map() David Hildenbrand (Arm)
2026-03-20 22:13 ` David Hildenbrand (Arm) [this message]
2026-03-20 22:13 ` [PATCH v2 10/15] mm/sparse: remove CONFIG_MEMORY_HOTPLUG-specific usemap allocation handling David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 11/15] mm: prepare to move subsection_map_init() to mm/sparse-vmemmap.c David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 12/15] mm/sparse: drop set_section_nid() from sparse_add_section() David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 13/15] mm/sparse: move sparse_init_one_section() to internal.h David Hildenbrand (Arm)
2026-03-23 8:49 ` David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 14/15] mm/sparse: move __section_mark_present() " David Hildenbrand (Arm)
2026-03-20 22:13 ` [PATCH v2 15/15] mm/sparse: move memory hotplug bits to sparse-vmemmap.c David Hildenbrand (Arm)
2026-03-27 2:58 ` [PATCH v2 00/15] mm: memory hot(un)plug and SPARSEMEM cleanups Andrew Morton
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