[RFC PATCH v4 10/13] memory-hotplug : implement register_page_bootmem_info_sectionof sparse-vmemmap

From: Yasuaki Ishimatsu
Date: Wed Jul 18 2012 - 06:16:08 EST


For removing memmap region of sparse-vmemmap which is allocated bootmem,
memmap region of sparse-vmemmap needs to be registered by get_page_bootmem().
So the patch searches pages of virtual mapping and registers the pages by
get_page_bootmem().

CC: David Rientjes <rientjes@xxxxxxxxxx>
CC: Jiang Liu <liuj97@xxxxxxxxx>
CC: Len Brown <len.brown@xxxxxxxxx>
CC: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
CC: Paul Mackerras <paulus@xxxxxxxxx>
CC: Christoph Lameter <cl@xxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
CC: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
CC: Wen Congyang <wency@xxxxxxxxxxxxxx>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>

---
arch/x86/mm/init_64.c | 52 +++++++++++++++++++++++++++++++++++++++++
include/linux/memory_hotplug.h | 2 +
include/linux/mm.h | 3 +-
mm/memory_hotplug.c | 23 +++++++++++++++---
4 files changed, 76 insertions(+), 4 deletions(-)

Index: linux-3.5-rc6/mm/memory_hotplug.c
===================================================================
--- linux-3.5-rc6.orig/mm/memory_hotplug.c 2012-07-18 18:01:24.221435622 +0900
+++ linux-3.5-rc6/mm/memory_hotplug.c 2012-07-18 18:01:28.156386427 +0900
@@ -91,8 +91,8 @@ static void release_memory_resource(stru
}

#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
-static void get_page_bootmem(unsigned long info, struct page *page,
- unsigned long type)
+void get_page_bootmem(unsigned long info, struct page *page,
+ unsigned long type)
{
unsigned long page_type;

@@ -164,8 +164,25 @@ static void register_page_bootmem_info_s

}
#else
-static inline void register_page_bootmem_info_section(unsigned long start_pfn)
+static void register_page_bootmem_info_section(unsigned long start_pfn)
{
+ unsigned long mapsize, section_nr;
+ struct mem_section *ms;
+ struct page *page, *memmap;
+
+ if (!pfn_valid(start_pfn))
+ return;
+
+ section_nr = pfn_to_section_nr(start_pfn);
+ ms = __nr_to_section(section_nr);
+
+ memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
+
+ page = virt_to_page(memmap);
+ mapsize = sizeof(struct page) * PAGES_PER_SECTION;
+ mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT;
+
+ register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION);
}
#endif

Index: linux-3.5-rc6/include/linux/mm.h
===================================================================
--- linux-3.5-rc6.orig/include/linux/mm.h 2012-07-18 17:59:51.225598230 +0900
+++ linux-3.5-rc6/include/linux/mm.h 2012-07-18 18:01:28.161386365 +0900
@@ -1586,7 +1586,8 @@ int vmemmap_populate_basepages(struct pa
unsigned long pages, int node);
int vmemmap_populate(struct page *start_page, unsigned long pages, int node);
void vmemmap_populate_print_last(void);
-
+void register_page_bootmem_memmap(unsigned long section_nr, struct page *map,
+ unsigned long size);

enum mf_flags {
MF_COUNT_INCREASED = 1 << 0,
Index: linux-3.5-rc6/arch/x86/mm/init_64.c
===================================================================
--- linux-3.5-rc6.orig/arch/x86/mm/init_64.c 2012-07-18 17:59:51.221598278 +0900
+++ linux-3.5-rc6/arch/x86/mm/init_64.c 2012-07-18 18:01:28.169386264 +0900
@@ -978,6 +978,58 @@ vmemmap_populate(struct page *start_page
return 0;
}

+void register_page_bootmem_memmap(unsigned long section_nr,
+ struct page *start_page, unsigned long size)
+{
+ unsigned long addr = (unsigned long)start_page;
+ unsigned long end = (unsigned long)(start_page + size);
+ unsigned long next;
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+
+ for (; addr < end; addr = next) {
+ pte_t *pte = NULL;
+
+ pgd = pgd_offset_k(addr);
+ if (pgd_none(*pgd)) {
+ next = (addr + PAGE_SIZE) & PAGE_MASK;
+ continue;
+ }
+ get_page_bootmem(section_nr, pgd_page(*pgd), MIX_SECTION_INFO);
+
+ pud = pud_offset(pgd, addr);
+ if (pud_none(*pud)) {
+ next = (addr + PAGE_SIZE) & PAGE_MASK;
+ continue;
+ }
+ get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO);
+
+ if (!cpu_has_pse) {
+ next = (addr + PAGE_SIZE) & PAGE_MASK;
+ pmd = pmd_offset(pud, addr);
+ if (pmd_none(*pmd))
+ continue;
+ get_page_bootmem(section_nr, pmd_page(*pmd),
+ MIX_SECTION_INFO);
+
+ pte = pte_offset_kernel(pmd, addr);
+ if (pte_none(*pte))
+ continue;
+ get_page_bootmem(section_nr, pte_page(*pte),
+ SECTION_INFO);
+ } else {
+ next = pmd_addr_end(addr, end);
+
+ pmd = pmd_offset(pud, addr);
+ if (pmd_none(*pmd))
+ continue;
+ get_page_bootmem(section_nr, pmd_page(*pmd),
+ SECTION_INFO);
+ }
+ }
+}
+
void __meminit vmemmap_populate_print_last(void)
{
if (p_start) {
Index: linux-3.5-rc6/include/linux/memory_hotplug.h
===================================================================
--- linux-3.5-rc6.orig/include/linux/memory_hotplug.h 2012-07-18 18:01:24.217435670 +0900
+++ linux-3.5-rc6/include/linux/memory_hotplug.h 2012-07-18 18:01:28.173386216 +0900
@@ -162,6 +162,8 @@ static inline void arch_refresh_nodedata

extern void register_page_bootmem_info_node(struct pglist_data *pgdat);
extern void put_page_bootmem(struct page *page);
+extern void get_page_bootmem(unsigned long ingo, struct page *page,
+ unsigned long type);

/*
* Lock for memory hotplug guarantees 1) all callbacks for memory hotplug

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