The patch titled
Subject: mm: use vmem_altmap code without CONFIG_ZONE_DEVICE
has been added to the -mm mm-unstable branch. Its filename is
mm-use-vmem_altmap-code-without-config_zone_device.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-use-vmem_altmap-code-without-config_zone_device.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: Sumanth Korikkar <sumanthk@xxxxxxxxxxxxx>
Subject: mm: use vmem_altmap code without CONFIG_ZONE_DEVICE
Date: Mon, 20 Nov 2023 15:53:54 +0100
vmem_altmap_free() and vmem_altmap_offset() could be utlized without
CONFIG_ZONE_DEVICE enabled. For example,
mm/memory_hotplug.c:__add_pages() relies on that. The altmap is no longer
restricted to ZONE_DEVICE handling, but instead depends on
CONFIG_SPARSEMEM_VMEMMAP.
When CONFIG_SPARSEMEM_VMEMMAP is disabled, these functions are defined as
inline stubs, ensuring compatibility with configurations that do not use
sparsemem vmemmap. Without it, lkp reported the following:
ld: arch/x86/mm/init_64.o: in function `remove_pagetable':
init_64.c:(.meminit.text+0xfc7): undefined reference to
`vmem_altmap_free'
Link: https://lkml.kernel.org/r/20231120145354.308999-4-sumanthk@xxxxxxxxxxxxx
Signed-off-by: Sumanth Korikkar <sumanthk@xxxxxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202311180545.VeyRXEDq-lkp@xxxxxxxxx/
Reviewed-by: Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/memremap.h | 12 ------------
include/linux/mm.h | 26 ++++++++++++++++++++++++++
mm/memremap.c | 14 +-------------
3 files changed, 27 insertions(+), 25 deletions(-)
--- a/include/linux/memremap.h~mm-use-vmem_altmap-code-without-config_zone_device
+++ a/include/linux/memremap.h
@@ -196,8 +196,6 @@ struct dev_pagemap *get_dev_pagemap(unsi
struct dev_pagemap *pgmap);
bool pgmap_pfn_valid(struct dev_pagemap *pgmap, unsigned long pfn);
-unsigned long vmem_altmap_offset(struct vmem_altmap *altmap);
-void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns);
unsigned long memremap_compat_align(void);
#else
static inline void *devm_memremap_pages(struct device *dev,
@@ -228,16 +226,6 @@ static inline bool pgmap_pfn_valid(struc
return false;
}
-static inline unsigned long vmem_altmap_offset(struct vmem_altmap *altmap)
-{
- return 0;
-}
-
-static inline void vmem_altmap_free(struct vmem_altmap *altmap,
- unsigned long nr_pfns)
-{
-}
-
/* when memremap_pages() is disabled all archs can remap a single page */
static inline unsigned long memremap_compat_align(void)
{
--- a/include/linux/mm.h~mm-use-vmem_altmap-code-without-config_zone_device
+++ a/include/linux/mm.h
@@ -3871,6 +3871,32 @@ void vmemmap_free(unsigned long start, u
struct vmem_altmap *altmap);
#endif
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+static inline unsigned long vmem_altmap_offset(struct vmem_altmap *altmap)
+{
+ /* number of pfns from base where pfn_to_page() is valid */
+ if (altmap)
+ return altmap->reserve + altmap->free;
+ return 0;
+}
+
+static inline void vmem_altmap_free(struct vmem_altmap *altmap,
+ unsigned long nr_pfns)
+{
+ altmap->alloc -= nr_pfns;
+}
+#else
+static inline unsigned long vmem_altmap_offset(struct vmem_altmap *altmap)
+{
+ return 0;
+}
+
+static inline void vmem_altmap_free(struct vmem_altmap *altmap,
+ unsigned long nr_pfns)
+{
+}
+#endif
+
#define VMEMMAP_RESERVE_NR 2
#ifdef CONFIG_ARCH_WANT_OPTIMIZE_DAX_VMEMMAP
static inline bool __vmemmap_can_optimize(struct vmem_altmap *altmap,
--- a/mm/memremap.c~mm-use-vmem_altmap-code-without-config_zone_device
+++ a/mm/memremap.c
@@ -7,6 +7,7 @@
#include <linux/memremap.h>
#include <linux/pfn_t.h>
#include <linux/swap.h>
+#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/swapops.h>
#include <linux/types.h>
@@ -422,19 +423,6 @@ void devm_memunmap_pages(struct device *
}
EXPORT_SYMBOL_GPL(devm_memunmap_pages);
-unsigned long vmem_altmap_offset(struct vmem_altmap *altmap)
-{
- /* number of pfns from base where pfn_to_page() is valid */
- if (altmap)
- return altmap->reserve + altmap->free;
- return 0;
-}
-
-void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns)
-{
- altmap->alloc -= nr_pfns;
-}
-
/**
* get_dev_pagemap() - take a new live reference on the dev_pagemap for @pfn
* @pfn: page frame number to lookup page_map
_
Patches currently in -mm which might be from sumanthk@xxxxxxxxxxxxx are
mm-memory_hotplug-add-missing-mem_hotplug_lock.patch
mm-memory_hotplug-fix-error-handling-in-add_memory_resource.patch
mm-use-vmem_altmap-code-without-config_zone_device.patch
