[patch] mm, hotplug: avoid compiling memory hotremove functions when disabled
David Rientjes
rientjes at google.com
Wed Apr 10 16:07:34 EST 2013
__remove_pages() is only necessary for CONFIG_MEMORY_HOTREMOVE. PowerPC
pseries will return -EOPNOTSUPP if unsupported.
Adding an #ifdef causes several other functions it depends on to also
become unnecessary, which saves in .text when disabled (it's disabled in
most defconfigs besides powerpc, including x86). remove_memory_block()
becomes static since it is not referenced outside of
drivers/base/memory.c.
Build tested on x86 and powerpc with CONFIG_MEMORY_HOTREMOVE both enabled
and disabled.
Signed-off-by: David Rientjes <rientjes at google.com>
---
arch/powerpc/platforms/pseries/hotplug-memory.c | 12 +++++
drivers/base/memory.c | 44 +++++++--------
include/linux/memory.h | 3 +-
include/linux/memory_hotplug.h | 4 +-
mm/memory_hotplug.c | 68 +++++++++++------------
mm/sparse.c | 72 +++++++++++++------------
6 files changed, 113 insertions(+), 90 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -72,6 +72,7 @@ unsigned long memory_block_size_bytes(void)
return get_memblock_size();
}
+#ifdef CONFIG_MEMORY_HOTREMOVE
static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)
{
unsigned long start, start_pfn;
@@ -153,6 +154,17 @@ static int pseries_remove_memory(struct device_node *np)
ret = pseries_remove_memblock(base, lmb_size);
return ret;
}
+#else
+static inline int pseries_remove_memblock(unsigned long base,
+ unsigned int memblock_size)
+{
+ return -EOPNOTSUPP;
+}
+static inline int pseries_remove_memory(struct device_node *np)
+{
+ return -EOPNOTSUPP;
+}
+#endif /* CONFIG_MEMORY_HOTREMOVE */
static int pseries_add_memory(struct device_node *np)
{
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -93,16 +93,6 @@ int register_memory(struct memory_block *memory)
return error;
}
-static void
-unregister_memory(struct memory_block *memory)
-{
- BUG_ON(memory->dev.bus != &memory_subsys);
-
- /* drop the ref. we got in remove_memory_block() */
- kobject_put(&memory->dev.kobj);
- device_unregister(&memory->dev);
-}
-
unsigned long __weak memory_block_size_bytes(void)
{
return MIN_MEMORY_BLOCK_SIZE;
@@ -637,8 +627,28 @@ static int add_memory_section(int nid, struct mem_section *section,
return ret;
}
-int remove_memory_block(unsigned long node_id, struct mem_section *section,
- int phys_device)
+/*
+ * need an interface for the VM to add new memory regions,
+ * but without onlining it.
+ */
+int register_new_memory(int nid, struct mem_section *section)
+{
+ return add_memory_section(nid, section, NULL, MEM_OFFLINE, HOTPLUG);
+}
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+static void
+unregister_memory(struct memory_block *memory)
+{
+ BUG_ON(memory->dev.bus != &memory_subsys);
+
+ /* drop the ref. we got in remove_memory_block() */
+ kobject_put(&memory->dev.kobj);
+ device_unregister(&memory->dev);
+}
+
+static int remove_memory_block(unsigned long node_id,
+ struct mem_section *section, int phys_device)
{
struct memory_block *mem;
@@ -661,15 +671,6 @@ int remove_memory_block(unsigned long node_id, struct mem_section *section,
return 0;
}
-/*
- * need an interface for the VM to add new memory regions,
- * but without onlining it.
- */
-int register_new_memory(int nid, struct mem_section *section)
-{
- return add_memory_section(nid, section, NULL, MEM_OFFLINE, HOTPLUG);
-}
-
int unregister_memory_section(struct mem_section *section)
{
if (!present_section(section))
@@ -677,6 +678,7 @@ int unregister_memory_section(struct mem_section *section)
return remove_memory_block(0, section, 0);
}
+#endif /* CONFIG_MEMORY_HOTREMOVE */
/*
* offline one memory block. If the memory block has been offlined, do nothing.
diff --git a/include/linux/memory.h b/include/linux/memory.h
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -114,9 +114,10 @@ extern void unregister_memory_notifier(struct notifier_block *nb);
extern int register_memory_isolate_notifier(struct notifier_block *nb);
extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
extern int register_new_memory(int, struct mem_section *);
+#ifdef CONFIG_MEMORY_HOTREMOVE
extern int unregister_memory_section(struct mem_section *);
+#endif
extern int memory_dev_init(void);
-extern int remove_memory_block(unsigned long, struct mem_section *, int);
extern int memory_notify(unsigned long val, void *v);
extern int memory_isolate_notify(unsigned long val, void *v);
extern struct memory_block *find_memory_block_hinted(struct mem_section *,
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -97,13 +97,13 @@ extern void __online_page_free(struct page *page);
#ifdef CONFIG_MEMORY_HOTREMOVE
extern bool is_pageblock_removable_nolock(struct page *page);
extern int arch_remove_memory(u64 start, u64 size);
+extern int __remove_pages(struct zone *zone, unsigned long start_pfn,
+ unsigned long nr_pages);
#endif /* CONFIG_MEMORY_HOTREMOVE */
/* reasonably generic interface to expand the physical pages in a zone */
extern int __add_pages(int nid, struct zone *zone, unsigned long start_pfn,
unsigned long nr_pages);
-extern int __remove_pages(struct zone *zone, unsigned long start_pfn,
- unsigned long nr_pages);
#ifdef CONFIG_NUMA
extern int memory_add_physaddr_to_nid(u64 start);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -436,6 +436,40 @@ static int __meminit __add_section(int nid, struct zone *zone,
return register_new_memory(nid, __pfn_to_section(phys_start_pfn));
}
+/*
+ * Reasonably generic function for adding memory. It is
+ * expected that archs that support memory hotplug will
+ * call this function after deciding the zone to which to
+ * add the new pages.
+ */
+int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn,
+ unsigned long nr_pages)
+{
+ unsigned long i;
+ int err = 0;
+ int start_sec, end_sec;
+ /* during initialize mem_map, align hot-added range to section */
+ start_sec = pfn_to_section_nr(phys_start_pfn);
+ end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
+
+ for (i = start_sec; i <= end_sec; i++) {
+ err = __add_section(nid, zone, i << PFN_SECTION_SHIFT);
+
+ /*
+ * EEXIST is finally dealt with by ioresource collision
+ * check. see add_memory() => register_memory_resource()
+ * Warning will be printed if there is collision.
+ */
+ if (err && (err != -EEXIST))
+ break;
+ err = 0;
+ }
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(__add_pages);
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
/* find the smallest valid pfn in the range [start_pfn, end_pfn) */
static int find_smallest_section_pfn(int nid, struct zone *zone,
unsigned long start_pfn,
@@ -658,39 +692,6 @@ static int __remove_section(struct zone *zone, struct mem_section *ms)
return 0;
}
-/*
- * Reasonably generic function for adding memory. It is
- * expected that archs that support memory hotplug will
- * call this function after deciding the zone to which to
- * add the new pages.
- */
-int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn,
- unsigned long nr_pages)
-{
- unsigned long i;
- int err = 0;
- int start_sec, end_sec;
- /* during initialize mem_map, align hot-added range to section */
- start_sec = pfn_to_section_nr(phys_start_pfn);
- end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
-
- for (i = start_sec; i <= end_sec; i++) {
- err = __add_section(nid, zone, i << PFN_SECTION_SHIFT);
-
- /*
- * EEXIST is finally dealt with by ioresource collision
- * check. see add_memory() => register_memory_resource()
- * Warning will be printed if there is collision.
- */
- if (err && (err != -EEXIST))
- break;
- err = 0;
- }
-
- return err;
-}
-EXPORT_SYMBOL_GPL(__add_pages);
-
/**
* __remove_pages() - remove sections of pages from a zone
* @zone: zone from which pages need to be removed
@@ -726,6 +727,7 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
return ret;
}
EXPORT_SYMBOL_GPL(__remove_pages);
+#endif /* CONFIG_MEMORY_HOTREMOVE */
int set_online_page_callback(online_page_callback_t callback)
{
diff --git a/mm/sparse.c b/mm/sparse.c
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -620,6 +620,7 @@ static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
vmemmap_free(start, end);
}
+#ifdef CONFIG_MEMORY_HOTREMOVE
static void free_map_bootmem(struct page *memmap, unsigned long nr_pages)
{
unsigned long start = (unsigned long)memmap;
@@ -627,6 +628,7 @@ static void free_map_bootmem(struct page *memmap, unsigned long nr_pages)
vmemmap_free(start, end);
}
+#endif /* CONFIG_MEMORY_HOTREMOVE */
#else
static struct page *__kmalloc_section_memmap(unsigned long nr_pages)
{
@@ -664,6 +666,7 @@ static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
get_order(sizeof(struct page) * nr_pages));
}
+#ifdef CONFIG_MEMORY_HOTREMOVE
static void free_map_bootmem(struct page *memmap, unsigned long nr_pages)
{
unsigned long maps_section_nr, removing_section_nr, i;
@@ -690,40 +693,9 @@ static void free_map_bootmem(struct page *memmap, unsigned long nr_pages)
put_page_bootmem(page);
}
}
+#endif /* CONFIG_MEMORY_HOTREMOVE */
#endif /* CONFIG_SPARSEMEM_VMEMMAP */
-static void free_section_usemap(struct page *memmap, unsigned long *usemap)
-{
- struct page *usemap_page;
- unsigned long nr_pages;
-
- if (!usemap)
- return;
-
- usemap_page = virt_to_page(usemap);
- /*
- * Check to see if allocation came from hot-plug-add
- */
- if (PageSlab(usemap_page) || PageCompound(usemap_page)) {
- kfree(usemap);
- if (memmap)
- __kfree_section_memmap(memmap, PAGES_PER_SECTION);
- return;
- }
-
- /*
- * The usemap came from bootmem. This is packed with other usemaps
- * on the section which has pgdat at boot time. Just keep it as is now.
- */
-
- if (memmap) {
- nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
- >> PAGE_SHIFT;
-
- free_map_bootmem(memmap, nr_pages);
- }
-}
-
/*
* returns the number of sections whose mem_maps were properly
* set. If this is <=0, then that means that the passed-in
@@ -800,6 +772,39 @@ static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
}
#endif
+#ifdef CONFIG_MEMORY_HOTREMOVE
+static void free_section_usemap(struct page *memmap, unsigned long *usemap)
+{
+ struct page *usemap_page;
+ unsigned long nr_pages;
+
+ if (!usemap)
+ return;
+
+ usemap_page = virt_to_page(usemap);
+ /*
+ * Check to see if allocation came from hot-plug-add
+ */
+ if (PageSlab(usemap_page) || PageCompound(usemap_page)) {
+ kfree(usemap);
+ if (memmap)
+ __kfree_section_memmap(memmap, PAGES_PER_SECTION);
+ return;
+ }
+
+ /*
+ * The usemap came from bootmem. This is packed with other usemaps
+ * on the section which has pgdat at boot time. Just keep it as is now.
+ */
+
+ if (memmap) {
+ nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
+ >> PAGE_SHIFT;
+
+ free_map_bootmem(memmap, nr_pages);
+ }
+}
+
void sparse_remove_one_section(struct zone *zone, struct mem_section *ms)
{
struct page *memmap = NULL;
@@ -819,4 +824,5 @@ void sparse_remove_one_section(struct zone *zone, struct mem_section *ms)
clear_hwpoisoned_pages(memmap, PAGES_PER_SECTION);
free_section_usemap(memmap, usemap);
}
-#endif
+#endif /* CONFIG_MEMORY_HOTREMOVE */
+#endif /* CONFIG_MEMORY_HOTPLUG */
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