| Message ID | 50B45400.20800@huawei.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
At 11/27/2012 01:47 PM, Jianguo Wu Wrote: > On 2012/11/1 17:44, Wen Congyang wrote: > >> From: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> >> >> All pages of virtual mapping in removed memory cannot be freed, since some pages >> used as PGD/PUD includes not only removed memory but also other memory. So the >> patch checks whether page can be freed or not. >> >> How to check whether page can be freed or not? >> 1. When removing memory, the page structs of the revmoved memory are filled >> with 0FD. >> 2. All page structs are filled with 0xFD on PT/PMD, PT/PMD can be cleared. >> In this case, the page used as PT/PMD can be freed. >> >> Applying patch, __remove_section() of CONFIG_SPARSEMEM_VMEMMAP is integrated >> into one. So __remove_section() of CONFIG_SPARSEMEM_VMEMMAP is deleted. >> >> Note: vmemmap_kfree() and vmemmap_free_bootmem() are not implemented for ia64, >> ppc, s390, and sparc. >> >> CC: David Rientjes <rientjes@google.com> >> CC: Jiang Liu <liuj97@gmail.com> >> CC: Len Brown <len.brown@intel.com> >> CC: Christoph Lameter <cl@linux.com> >> Cc: Minchan Kim <minchan.kim@gmail.com> >> CC: Andrew Morton <akpm@linux-foundation.org> >> CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> >> CC: Wen Congyang <wency@cn.fujitsu.com> >> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> >> --- >> arch/ia64/mm/discontig.c | 8 ++++ >> arch/powerpc/mm/init_64.c | 8 ++++ >> arch/s390/mm/vmem.c | 8 ++++ >> arch/sparc/mm/init_64.c | 8 ++++ >> arch/x86/mm/init_64.c | 119 ++++++++++++++++++++++++++++++++++++++++++++++ >> include/linux/mm.h | 2 + >> mm/memory_hotplug.c | 17 +------ >> mm/sparse.c | 5 +- >> 8 files changed, 158 insertions(+), 17 deletions(-) >> >> diff --git a/arch/ia64/mm/discontig.c b/arch/ia64/mm/discontig.c >> index 33943db..0d23b69 100644 >> --- a/arch/ia64/mm/discontig.c >> +++ b/arch/ia64/mm/discontig.c >> @@ -823,6 +823,14 @@ int __meminit vmemmap_populate(struct page *start_page, >> return vmemmap_populate_basepages(start_page, size, node); >> } >> >> +void vmemmap_kfree(struct page *memmap, unsigned long nr_pages) >> +{ >> +} >> + >> +void vmemmap_free_bootmem(struct page *memmap, unsigned long nr_pages) >> +{ >> +} >> + >> void register_page_bootmem_memmap(unsigned long section_nr, >> struct page *start_page, unsigned long size) >> { >> diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c >> index 6466440..df7d155 100644 >> --- a/arch/powerpc/mm/init_64.c >> +++ b/arch/powerpc/mm/init_64.c >> @@ -298,6 +298,14 @@ int __meminit vmemmap_populate(struct page *start_page, >> return 0; >> } >> >> +void vmemmap_kfree(struct page *memmap, unsigned long nr_pages) >> +{ >> +} >> + >> +void vmemmap_free_bootmem(struct page *memmap, unsigned long nr_pages) >> +{ >> +} >> + >> void register_page_bootmem_memmap(unsigned long section_nr, >> struct page *start_page, unsigned long size) >> { >> diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c >> index 4f4803a..ab69c34 100644 >> --- a/arch/s390/mm/vmem.c >> +++ b/arch/s390/mm/vmem.c >> @@ -236,6 +236,14 @@ out: >> return ret; >> } >> >> +void vmemmap_kfree(struct page *memmap, unsigned long nr_pages) >> +{ >> +} >> + >> +void vmemmap_free_bootmem(struct page *memmap, unsigned long nr_pages) >> +{ >> +} >> + >> void register_page_bootmem_memmap(unsigned long section_nr, >> struct page *start_page, unsigned long size) >> { >> diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c >> index 75a984b..546855d 100644 >> --- a/arch/sparc/mm/init_64.c >> +++ b/arch/sparc/mm/init_64.c >> @@ -2232,6 +2232,14 @@ void __meminit vmemmap_populate_print_last(void) >> } >> } >> >> +void vmemmap_kfree(struct page *memmap, unsigned long nr_pages) >> +{ >> +} >> + >> +void vmemmap_free_bootmem(struct page *memmap, unsigned long nr_pages) >> +{ >> +} >> + >> void register_page_bootmem_memmap(unsigned long section_nr, >> struct page *start_page, unsigned long size) >> { >> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c >> index 795dae3..e85626d 100644 >> --- a/arch/x86/mm/init_64.c >> +++ b/arch/x86/mm/init_64.c >> @@ -998,6 +998,125 @@ vmemmap_populate(struct page *start_page, unsigned long size, int node) >> return 0; >> } >> >> +#define PAGE_INUSE 0xFD >> + >> +unsigned long find_and_clear_pte_page(unsigned long addr, unsigned long end, >> + struct page **pp, int *page_size) >> +{ >> + pgd_t *pgd; >> + pud_t *pud; >> + pmd_t *pmd; >> + pte_t *pte = NULL; >> + void *page_addr; >> + unsigned long next; >> + >> + *pp = NULL; >> + >> + pgd = pgd_offset_k(addr); >> + if (pgd_none(*pgd)) >> + return pgd_addr_end(addr, end); >> + >> + pud = pud_offset(pgd, addr); >> + if (pud_none(*pud)) >> + return pud_addr_end(addr, end); >> + >> + if (!cpu_has_pse) { >> + next = (addr + PAGE_SIZE) & PAGE_MASK; >> + pmd = pmd_offset(pud, addr); >> + if (pmd_none(*pmd)) >> + return next; >> + >> + pte = pte_offset_kernel(pmd, addr); >> + if (pte_none(*pte)) >> + return next; >> + >> + *page_size = PAGE_SIZE; >> + *pp = pte_page(*pte); >> + } else { >> + next = pmd_addr_end(addr, end); >> + >> + pmd = pmd_offset(pud, addr); >> + if (pmd_none(*pmd)) >> + return next; >> + >> + *page_size = PMD_SIZE; >> + *pp = pmd_page(*pmd); >> + } >> + >> + /* >> + * Removed page structs are filled with 0xFD. >> + */ >> + memset((void *)addr, PAGE_INUSE, next - addr); >> + >> + page_addr = page_address(*pp); >> + >> + /* >> + * Check the page is filled with 0xFD or not. >> + * memchr_inv() returns the address. In this case, we cannot >> + * clear PTE/PUD entry, since the page is used by other. >> + * So we cannot also free the page. >> + * >> + * memchr_inv() returns NULL. In this case, we can clear >> + * PTE/PUD entry, since the page is not used by other. >> + * So we can also free the page. >> + */ >> + if (memchr_inv(page_addr, PAGE_INUSE, *page_size)) { >> + *pp = NULL; >> + return next; >> + } >> + >> + if (!cpu_has_pse) >> + pte_clear(&init_mm, addr, pte); >> + else >> + pmd_clear(pmd); >> + >> + return next; >> +} >> + >> +void vmemmap_kfree(struct page *memmap, unsigned long nr_pages) >> +{ >> + unsigned long addr = (unsigned long)memmap; >> + unsigned long end = (unsigned long)(memmap + nr_pages); >> + unsigned long next; >> + struct page *page; >> + int page_size; >> + >> + for (; addr < end; addr = next) { >> + page = NULL; >> + page_size = 0; >> + next = find_and_clear_pte_page(addr, end, &page, &page_size); >> + if (!page) >> + continue; >> + >> + free_pages((unsigned long)page_address(page), >> + get_order(page_size)); >> + __flush_tlb_one(addr); >> + } >> +} >> + >> +void vmemmap_free_bootmem(struct page *memmap, unsigned long nr_pages) >> +{ >> + unsigned long addr = (unsigned long)memmap; >> + unsigned long end = (unsigned long)(memmap + nr_pages); >> + unsigned long next; >> + struct page *page; >> + int page_size; >> + unsigned long magic; >> + >> + for (; addr < end; addr = next) { >> + page = NULL; >> + page_size = 0; >> + next = find_and_clear_pte_page(addr, end, &page, &page_size); >> + if (!page) >> + continue; >> + >> + magic = (unsigned long) page->lru.next; >> + if (magic == SECTION_INFO) >> + put_page_bootmem(page); >> + flush_tlb_kernel_range(addr, end); >> + } >> +} >> + >> void register_page_bootmem_memmap(unsigned long section_nr, >> struct page *start_page, unsigned long size) >> { >> diff --git a/include/linux/mm.h b/include/linux/mm.h >> index 8e5a56f..42b8723 100644 >> --- a/include/linux/mm.h >> +++ b/include/linux/mm.h >> @@ -1642,6 +1642,8 @@ 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); >> +void vmemmap_kfree(struct page *memmpa, unsigned long nr_pages); >> +void vmemmap_free_bootmem(struct page *memmpa, unsigned long nr_pages); >> >> enum mf_flags { >> MF_COUNT_INCREASED = 1 << 0, >> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c >> index db9806c..03153cf 100644 >> --- a/mm/memory_hotplug.c >> +++ b/mm/memory_hotplug.c >> @@ -312,19 +312,6 @@ static int __meminit __add_section(int nid, struct zone *zone, >> return register_new_memory(nid, __pfn_to_section(phys_start_pfn)); >> } >> >> -#ifdef CONFIG_SPARSEMEM_VMEMMAP >> -static int __remove_section(struct zone *zone, struct mem_section *ms) >> -{ >> - int ret = -EINVAL; >> - >> - if (!valid_section(ms)) >> - return ret; >> - >> - ret = unregister_memory_section(ms); >> - >> - return ret; >> -} >> -#else >> static int __remove_section(struct zone *zone, struct mem_section *ms) >> { >> unsigned long flags; >> @@ -341,9 +328,9 @@ static int __remove_section(struct zone *zone, struct mem_section *ms) >> pgdat_resize_lock(pgdat, &flags); >> sparse_remove_one_section(zone, ms); >> pgdat_resize_unlock(pgdat, &flags); >> - return 0; >> + >> + return ret; >> } >> -#endif >> >> /* >> * Reasonably generic function for adding memory. It is >> diff --git a/mm/sparse.c b/mm/sparse.c >> index fac95f2..ab9d755 100644 >> --- a/mm/sparse.c >> +++ b/mm/sparse.c >> @@ -613,12 +613,13 @@ static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid, >> /* This will make the necessary allocations eventually. */ >> return sparse_mem_map_populate(pnum, nid); >> } >> -static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages) >> +static void __kfree_section_memmap(struct page *page, unsigned long nr_pages) >> { >> - return; /* XXX: Not implemented yet */ >> + vmemmap_kfree(page, nr_pages); >> } >> static void free_map_bootmem(struct page *page, unsigned long nr_pages) >> { >> + vmemmap_free_bootmem(page, nr_pages); >> } > > Hi Congyang, > For vmemmap, nr_pages should be PAGES_PER_SECTION for free_map_bootmem(), > which is passed by free_section_usemap(), right? Yes, you are right. I will merge it into my patchset. I will sent the new patchset later today. Thanks Wen Congyang > But now, nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page)) >> PAGE_SHIFT. > > Signed-off-by: Jianguo Wu <wujianguo@huawei.com> > --- > mm/sparse.c | 4 ++++ > 1 files changed, 4 insertions(+), 0 deletions(-) > > diff --git a/mm/sparse.c b/mm/sparse.c > index fac95f2..31e5282 100644 > --- a/mm/sparse.c > +++ b/mm/sparse.c > @@ -713,8 +713,12 @@ static void free_section_usemap(struct page *memmap, unsigned long *usemap) > struct page *memmap_page; > memmap_page = virt_to_page(memmap); > > +#ifdef CONFIG_SPARSEMEM_VMEMMAP > + nr_pages = PAGES_PER_SECTION; > +#else > nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page)) > >> PAGE_SHIFT; > +#endif > > free_map_bootmem(memmap_page, nr_pages); > } -- To unsubscribe from this list: send the line "unsubscribe linux-sh" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
At 11/27/2012 01:47 PM, Jianguo Wu Wrote: > On 2012/11/1 17:44, Wen Congyang wrote: > >> From: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> >> >> All pages of virtual mapping in removed memory cannot be freed, since some pages >> used as PGD/PUD includes not only removed memory but also other memory. So the >> patch checks whether page can be freed or not. >> >> How to check whether page can be freed or not? >> 1. When removing memory, the page structs of the revmoved memory are filled >> with 0FD. >> 2. All page structs are filled with 0xFD on PT/PMD, PT/PMD can be cleared. >> In this case, the page used as PT/PMD can be freed. >> >> Applying patch, __remove_section() of CONFIG_SPARSEMEM_VMEMMAP is integrated >> into one. So __remove_section() of CONFIG_SPARSEMEM_VMEMMAP is deleted. >> >> Note: vmemmap_kfree() and vmemmap_free_bootmem() are not implemented for ia64, >> ppc, s390, and sparc. >> >> CC: David Rientjes <rientjes@google.com> >> CC: Jiang Liu <liuj97@gmail.com> >> CC: Len Brown <len.brown@intel.com> >> CC: Christoph Lameter <cl@linux.com> >> Cc: Minchan Kim <minchan.kim@gmail.com> >> CC: Andrew Morton <akpm@linux-foundation.org> >> CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> >> CC: Wen Congyang <wency@cn.fujitsu.com> >> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> >> --- >> arch/ia64/mm/discontig.c | 8 ++++ >> arch/powerpc/mm/init_64.c | 8 ++++ >> arch/s390/mm/vmem.c | 8 ++++ >> arch/sparc/mm/init_64.c | 8 ++++ >> arch/x86/mm/init_64.c | 119 ++++++++++++++++++++++++++++++++++++++++++++++ >> include/linux/mm.h | 2 + >> mm/memory_hotplug.c | 17 +------ >> mm/sparse.c | 5 +- >> 8 files changed, 158 insertions(+), 17 deletions(-) >> >> diff --git a/arch/ia64/mm/discontig.c b/arch/ia64/mm/discontig.c >> index 33943db..0d23b69 100644 >> --- a/arch/ia64/mm/discontig.c >> +++ b/arch/ia64/mm/discontig.c >> @@ -823,6 +823,14 @@ int __meminit vmemmap_populate(struct page *start_page, >> return vmemmap_populate_basepages(start_page, size, node); >> } >> >> +void vmemmap_kfree(struct page *memmap, unsigned long nr_pages) >> +{ >> +} >> + >> +void vmemmap_free_bootmem(struct page *memmap, unsigned long nr_pages) >> +{ >> +} >> + >> void register_page_bootmem_memmap(unsigned long section_nr, >> struct page *start_page, unsigned long size) >> { >> diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c >> index 6466440..df7d155 100644 >> --- a/arch/powerpc/mm/init_64.c >> +++ b/arch/powerpc/mm/init_64.c >> @@ -298,6 +298,14 @@ int __meminit vmemmap_populate(struct page *start_page, >> return 0; >> } >> >> +void vmemmap_kfree(struct page *memmap, unsigned long nr_pages) >> +{ >> +} >> + >> +void vmemmap_free_bootmem(struct page *memmap, unsigned long nr_pages) >> +{ >> +} >> + >> void register_page_bootmem_memmap(unsigned long section_nr, >> struct page *start_page, unsigned long size) >> { >> diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c >> index 4f4803a..ab69c34 100644 >> --- a/arch/s390/mm/vmem.c >> +++ b/arch/s390/mm/vmem.c >> @@ -236,6 +236,14 @@ out: >> return ret; >> } >> >> +void vmemmap_kfree(struct page *memmap, unsigned long nr_pages) >> +{ >> +} >> + >> +void vmemmap_free_bootmem(struct page *memmap, unsigned long nr_pages) >> +{ >> +} >> + >> void register_page_bootmem_memmap(unsigned long section_nr, >> struct page *start_page, unsigned long size) >> { >> diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c >> index 75a984b..546855d 100644 >> --- a/arch/sparc/mm/init_64.c >> +++ b/arch/sparc/mm/init_64.c >> @@ -2232,6 +2232,14 @@ void __meminit vmemmap_populate_print_last(void) >> } >> } >> >> +void vmemmap_kfree(struct page *memmap, unsigned long nr_pages) >> +{ >> +} >> + >> +void vmemmap_free_bootmem(struct page *memmap, unsigned long nr_pages) >> +{ >> +} >> + >> void register_page_bootmem_memmap(unsigned long section_nr, >> struct page *start_page, unsigned long size) >> { >> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c >> index 795dae3..e85626d 100644 >> --- a/arch/x86/mm/init_64.c >> +++ b/arch/x86/mm/init_64.c >> @@ -998,6 +998,125 @@ vmemmap_populate(struct page *start_page, unsigned long size, int node) >> return 0; >> } >> >> +#define PAGE_INUSE 0xFD >> + >> +unsigned long find_and_clear_pte_page(unsigned long addr, unsigned long end, >> + struct page **pp, int *page_size) >> +{ >> + pgd_t *pgd; >> + pud_t *pud; >> + pmd_t *pmd; >> + pte_t *pte = NULL; >> + void *page_addr; >> + unsigned long next; >> + >> + *pp = NULL; >> + >> + pgd = pgd_offset_k(addr); >> + if (pgd_none(*pgd)) >> + return pgd_addr_end(addr, end); >> + >> + pud = pud_offset(pgd, addr); >> + if (pud_none(*pud)) >> + return pud_addr_end(addr, end); >> + >> + if (!cpu_has_pse) { >> + next = (addr + PAGE_SIZE) & PAGE_MASK; >> + pmd = pmd_offset(pud, addr); >> + if (pmd_none(*pmd)) >> + return next; >> + >> + pte = pte_offset_kernel(pmd, addr); >> + if (pte_none(*pte)) >> + return next; >> + >> + *page_size = PAGE_SIZE; >> + *pp = pte_page(*pte); >> + } else { >> + next = pmd_addr_end(addr, end); >> + >> + pmd = pmd_offset(pud, addr); >> + if (pmd_none(*pmd)) >> + return next; >> + >> + *page_size = PMD_SIZE; >> + *pp = pmd_page(*pmd); >> + } >> + >> + /* >> + * Removed page structs are filled with 0xFD. >> + */ >> + memset((void *)addr, PAGE_INUSE, next - addr); >> + >> + page_addr = page_address(*pp); >> + >> + /* >> + * Check the page is filled with 0xFD or not. >> + * memchr_inv() returns the address. In this case, we cannot >> + * clear PTE/PUD entry, since the page is used by other. >> + * So we cannot also free the page. >> + * >> + * memchr_inv() returns NULL. In this case, we can clear >> + * PTE/PUD entry, since the page is not used by other. >> + * So we can also free the page. >> + */ >> + if (memchr_inv(page_addr, PAGE_INUSE, *page_size)) { >> + *pp = NULL; >> + return next; >> + } >> + >> + if (!cpu_has_pse) >> + pte_clear(&init_mm, addr, pte); >> + else >> + pmd_clear(pmd); >> + >> + return next; >> +} >> + >> +void vmemmap_kfree(struct page *memmap, unsigned long nr_pages) >> +{ >> + unsigned long addr = (unsigned long)memmap; >> + unsigned long end = (unsigned long)(memmap + nr_pages); >> + unsigned long next; >> + struct page *page; >> + int page_size; >> + >> + for (; addr < end; addr = next) { >> + page = NULL; >> + page_size = 0; >> + next = find_and_clear_pte_page(addr, end, &page, &page_size); >> + if (!page) >> + continue; >> + >> + free_pages((unsigned long)page_address(page), >> + get_order(page_size)); >> + __flush_tlb_one(addr); >> + } >> +} >> + >> +void vmemmap_free_bootmem(struct page *memmap, unsigned long nr_pages) >> +{ >> + unsigned long addr = (unsigned long)memmap; >> + unsigned long end = (unsigned long)(memmap + nr_pages); >> + unsigned long next; >> + struct page *page; >> + int page_size; >> + unsigned long magic; >> + >> + for (; addr < end; addr = next) { >> + page = NULL; >> + page_size = 0; >> + next = find_and_clear_pte_page(addr, end, &page, &page_size); >> + if (!page) >> + continue; >> + >> + magic = (unsigned long) page->lru.next; >> + if (magic == SECTION_INFO) >> + put_page_bootmem(page); >> + flush_tlb_kernel_range(addr, end); >> + } >> +} >> + >> void register_page_bootmem_memmap(unsigned long section_nr, >> struct page *start_page, unsigned long size) >> { >> diff --git a/include/linux/mm.h b/include/linux/mm.h >> index 8e5a56f..42b8723 100644 >> --- a/include/linux/mm.h >> +++ b/include/linux/mm.h >> @@ -1642,6 +1642,8 @@ 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); >> +void vmemmap_kfree(struct page *memmpa, unsigned long nr_pages); >> +void vmemmap_free_bootmem(struct page *memmpa, unsigned long nr_pages); >> >> enum mf_flags { >> MF_COUNT_INCREASED = 1 << 0, >> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c >> index db9806c..03153cf 100644 >> --- a/mm/memory_hotplug.c >> +++ b/mm/memory_hotplug.c >> @@ -312,19 +312,6 @@ static int __meminit __add_section(int nid, struct zone *zone, >> return register_new_memory(nid, __pfn_to_section(phys_start_pfn)); >> } >> >> -#ifdef CONFIG_SPARSEMEM_VMEMMAP >> -static int __remove_section(struct zone *zone, struct mem_section *ms) >> -{ >> - int ret = -EINVAL; >> - >> - if (!valid_section(ms)) >> - return ret; >> - >> - ret = unregister_memory_section(ms); >> - >> - return ret; >> -} >> -#else >> static int __remove_section(struct zone *zone, struct mem_section *ms) >> { >> unsigned long flags; >> @@ -341,9 +328,9 @@ static int __remove_section(struct zone *zone, struct mem_section *ms) >> pgdat_resize_lock(pgdat, &flags); >> sparse_remove_one_section(zone, ms); >> pgdat_resize_unlock(pgdat, &flags); >> - return 0; >> + >> + return ret; >> } >> -#endif >> >> /* >> * Reasonably generic function for adding memory. It is >> diff --git a/mm/sparse.c b/mm/sparse.c >> index fac95f2..ab9d755 100644 >> --- a/mm/sparse.c >> +++ b/mm/sparse.c >> @@ -613,12 +613,13 @@ static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid, >> /* This will make the necessary allocations eventually. */ >> return sparse_mem_map_populate(pnum, nid); >> } >> -static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages) >> +static void __kfree_section_memmap(struct page *page, unsigned long nr_pages) >> { >> - return; /* XXX: Not implemented yet */ >> + vmemmap_kfree(page, nr_pages); >> } >> static void free_map_bootmem(struct page *page, unsigned long nr_pages) >> { >> + vmemmap_free_bootmem(page, nr_pages); >> } > > Hi Congyang, > For vmemmap, nr_pages should be PAGES_PER_SECTION for free_map_bootmem(), > which is passed by free_section_usemap(), right? > But now, nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page)) >> PAGE_SHIFT. > > Signed-off-by: Jianguo Wu <wujianguo@huawei.com> > --- > mm/sparse.c | 4 ++++ > 1 files changed, 4 insertions(+), 0 deletions(-) > > diff --git a/mm/sparse.c b/mm/sparse.c > index fac95f2..31e5282 100644 > --- a/mm/sparse.c > +++ b/mm/sparse.c > @@ -713,8 +713,12 @@ static void free_section_usemap(struct page *memmap, unsigned long *usemap) > struct page *memmap_page; > memmap_page = virt_to_page(memmap); > > +#ifdef CONFIG_SPARSEMEM_VMEMMAP > + nr_pages = PAGES_PER_SECTION; > +#else > nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page)) > >> PAGE_SHIFT; > +#endif Hmm, to avoid using ifdef, I think we can pass PAGE_PER_SECTION to free_map_bootmem(), and calculate how many pages is used to store struct page. Thanks Wen Congyang > > free_map_bootmem(memmap_page, nr_pages); > } -- To unsubscribe from this list: send the line "unsubscribe linux-sh" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2012/11/27 14:49, Wen Congyang wrote: > At 11/27/2012 01:47 PM, Jianguo Wu Wrote: >> On 2012/11/1 17:44, Wen Congyang wrote: >> >>> From: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> >>> >>> All pages of virtual mapping in removed memory cannot be freed, since some pages >>> used as PGD/PUD includes not only removed memory but also other memory. So the >>> patch checks whether page can be freed or not. >>> >>> How to check whether page can be freed or not? >>> 1. When removing memory, the page structs of the revmoved memory are filled >>> with 0FD. >>> 2. All page structs are filled with 0xFD on PT/PMD, PT/PMD can be cleared. >>> In this case, the page used as PT/PMD can be freed. >>> >>> Applying patch, __remove_section() of CONFIG_SPARSEMEM_VMEMMAP is integrated >>> into one. So __remove_section() of CONFIG_SPARSEMEM_VMEMMAP is deleted. >>> >>> Note: vmemmap_kfree() and vmemmap_free_bootmem() are not implemented for ia64, >>> ppc, s390, and sparc. >>> >>> CC: David Rientjes <rientjes@google.com> >>> CC: Jiang Liu <liuj97@gmail.com> >>> CC: Len Brown <len.brown@intel.com> >>> CC: Christoph Lameter <cl@linux.com> >>> Cc: Minchan Kim <minchan.kim@gmail.com> >>> CC: Andrew Morton <akpm@linux-foundation.org> >>> CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> >>> CC: Wen Congyang <wency@cn.fujitsu.com> >>> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> >>> --- >>> arch/ia64/mm/discontig.c | 8 ++++ >>> arch/powerpc/mm/init_64.c | 8 ++++ >>> arch/s390/mm/vmem.c | 8 ++++ >>> arch/sparc/mm/init_64.c | 8 ++++ >>> arch/x86/mm/init_64.c | 119 ++++++++++++++++++++++++++++++++++++++++++++++ >>> include/linux/mm.h | 2 + >>> mm/memory_hotplug.c | 17 +------ >>> mm/sparse.c | 5 +- >>> 8 files changed, 158 insertions(+), 17 deletions(-) >>> >>> diff --git a/arch/ia64/mm/discontig.c b/arch/ia64/mm/discontig.c >>> index 33943db..0d23b69 100644 >>> --- a/arch/ia64/mm/discontig.c >>> +++ b/arch/ia64/mm/discontig.c >>> @@ -823,6 +823,14 @@ int __meminit vmemmap_populate(struct page *start_page, >>> return vmemmap_populate_basepages(start_page, size, node); >>> } >>> >>> +void vmemmap_kfree(struct page *memmap, unsigned long nr_pages) >>> +{ >>> +} >>> + >>> +void vmemmap_free_bootmem(struct page *memmap, unsigned long nr_pages) >>> +{ >>> +} >>> + >>> void register_page_bootmem_memmap(unsigned long section_nr, >>> struct page *start_page, unsigned long size) >>> { >>> diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c >>> index 6466440..df7d155 100644 >>> --- a/arch/powerpc/mm/init_64.c >>> +++ b/arch/powerpc/mm/init_64.c >>> @@ -298,6 +298,14 @@ int __meminit vmemmap_populate(struct page *start_page, >>> return 0; >>> } >>> >>> +void vmemmap_kfree(struct page *memmap, unsigned long nr_pages) >>> +{ >>> +} >>> + >>> +void vmemmap_free_bootmem(struct page *memmap, unsigned long nr_pages) >>> +{ >>> +} >>> + >>> void register_page_bootmem_memmap(unsigned long section_nr, >>> struct page *start_page, unsigned long size) >>> { >>> diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c >>> index 4f4803a..ab69c34 100644 >>> --- a/arch/s390/mm/vmem.c >>> +++ b/arch/s390/mm/vmem.c >>> @@ -236,6 +236,14 @@ out: >>> return ret; >>> } >>> >>> +void vmemmap_kfree(struct page *memmap, unsigned long nr_pages) >>> +{ >>> +} >>> + >>> +void vmemmap_free_bootmem(struct page *memmap, unsigned long nr_pages) >>> +{ >>> +} >>> + >>> void register_page_bootmem_memmap(unsigned long section_nr, >>> struct page *start_page, unsigned long size) >>> { >>> diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c >>> index 75a984b..546855d 100644 >>> --- a/arch/sparc/mm/init_64.c >>> +++ b/arch/sparc/mm/init_64.c >>> @@ -2232,6 +2232,14 @@ void __meminit vmemmap_populate_print_last(void) >>> } >>> } >>> >>> +void vmemmap_kfree(struct page *memmap, unsigned long nr_pages) >>> +{ >>> +} >>> + >>> +void vmemmap_free_bootmem(struct page *memmap, unsigned long nr_pages) >>> +{ >>> +} >>> + >>> void register_page_bootmem_memmap(unsigned long section_nr, >>> struct page *start_page, unsigned long size) >>> { >>> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c >>> index 795dae3..e85626d 100644 >>> --- a/arch/x86/mm/init_64.c >>> +++ b/arch/x86/mm/init_64.c >>> @@ -998,6 +998,125 @@ vmemmap_populate(struct page *start_page, unsigned long size, int node) >>> return 0; >>> } >>> >>> +#define PAGE_INUSE 0xFD >>> + >>> +unsigned long find_and_clear_pte_page(unsigned long addr, unsigned long end, >>> + struct page **pp, int *page_size) >>> +{ >>> + pgd_t *pgd; >>> + pud_t *pud; >>> + pmd_t *pmd; >>> + pte_t *pte = NULL; >>> + void *page_addr; >>> + unsigned long next; >>> + >>> + *pp = NULL; >>> + >>> + pgd = pgd_offset_k(addr); >>> + if (pgd_none(*pgd)) >>> + return pgd_addr_end(addr, end); >>> + >>> + pud = pud_offset(pgd, addr); >>> + if (pud_none(*pud)) >>> + return pud_addr_end(addr, end); >>> + >>> + if (!cpu_has_pse) { >>> + next = (addr + PAGE_SIZE) & PAGE_MASK; >>> + pmd = pmd_offset(pud, addr); >>> + if (pmd_none(*pmd)) >>> + return next; >>> + >>> + pte = pte_offset_kernel(pmd, addr); >>> + if (pte_none(*pte)) >>> + return next; >>> + >>> + *page_size = PAGE_SIZE; >>> + *pp = pte_page(*pte); >>> + } else { >>> + next = pmd_addr_end(addr, end); >>> + >>> + pmd = pmd_offset(pud, addr); >>> + if (pmd_none(*pmd)) >>> + return next; >>> + >>> + *page_size = PMD_SIZE; >>> + *pp = pmd_page(*pmd); >>> + } >>> + >>> + /* >>> + * Removed page structs are filled with 0xFD. >>> + */ >>> + memset((void *)addr, PAGE_INUSE, next - addr); >>> + >>> + page_addr = page_address(*pp); >>> + >>> + /* >>> + * Check the page is filled with 0xFD or not. >>> + * memchr_inv() returns the address. In this case, we cannot >>> + * clear PTE/PUD entry, since the page is used by other. >>> + * So we cannot also free the page. >>> + * >>> + * memchr_inv() returns NULL. In this case, we can clear >>> + * PTE/PUD entry, since the page is not used by other. >>> + * So we can also free the page. >>> + */ >>> + if (memchr_inv(page_addr, PAGE_INUSE, *page_size)) { >>> + *pp = NULL; >>> + return next; >>> + } >>> + >>> + if (!cpu_has_pse) >>> + pte_clear(&init_mm, addr, pte); >>> + else >>> + pmd_clear(pmd); >>> + >>> + return next; >>> +} >>> + >>> +void vmemmap_kfree(struct page *memmap, unsigned long nr_pages) >>> +{ >>> + unsigned long addr = (unsigned long)memmap; >>> + unsigned long end = (unsigned long)(memmap + nr_pages); >>> + unsigned long next; >>> + struct page *page; >>> + int page_size; >>> + >>> + for (; addr < end; addr = next) { >>> + page = NULL; >>> + page_size = 0; >>> + next = find_and_clear_pte_page(addr, end, &page, &page_size); >>> + if (!page) >>> + continue; >>> + >>> + free_pages((unsigned long)page_address(page), >>> + get_order(page_size)); >>> + __flush_tlb_one(addr); >>> + } >>> +} >>> + >>> +void vmemmap_free_bootmem(struct page *memmap, unsigned long nr_pages) >>> +{ >>> + unsigned long addr = (unsigned long)memmap; >>> + unsigned long end = (unsigned long)(memmap + nr_pages); >>> + unsigned long next; >>> + struct page *page; >>> + int page_size; >>> + unsigned long magic; >>> + >>> + for (; addr < end; addr = next) { >>> + page = NULL; >>> + page_size = 0; >>> + next = find_and_clear_pte_page(addr, end, &page, &page_size); >>> + if (!page) >>> + continue; >>> + >>> + magic = (unsigned long) page->lru.next; >>> + if (magic == SECTION_INFO) >>> + put_page_bootmem(page); >>> + flush_tlb_kernel_range(addr, end); >>> + } >>> +} >>> + >>> void register_page_bootmem_memmap(unsigned long section_nr, >>> struct page *start_page, unsigned long size) >>> { >>> diff --git a/include/linux/mm.h b/include/linux/mm.h >>> index 8e5a56f..42b8723 100644 >>> --- a/include/linux/mm.h >>> +++ b/include/linux/mm.h >>> @@ -1642,6 +1642,8 @@ 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); >>> +void vmemmap_kfree(struct page *memmpa, unsigned long nr_pages); >>> +void vmemmap_free_bootmem(struct page *memmpa, unsigned long nr_pages); >>> >>> enum mf_flags { >>> MF_COUNT_INCREASED = 1 << 0, >>> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c >>> index db9806c..03153cf 100644 >>> --- a/mm/memory_hotplug.c >>> +++ b/mm/memory_hotplug.c >>> @@ -312,19 +312,6 @@ static int __meminit __add_section(int nid, struct zone *zone, >>> return register_new_memory(nid, __pfn_to_section(phys_start_pfn)); >>> } >>> >>> -#ifdef CONFIG_SPARSEMEM_VMEMMAP >>> -static int __remove_section(struct zone *zone, struct mem_section *ms) >>> -{ >>> - int ret = -EINVAL; >>> - >>> - if (!valid_section(ms)) >>> - return ret; >>> - >>> - ret = unregister_memory_section(ms); >>> - >>> - return ret; >>> -} >>> -#else >>> static int __remove_section(struct zone *zone, struct mem_section *ms) >>> { >>> unsigned long flags; >>> @@ -341,9 +328,9 @@ static int __remove_section(struct zone *zone, struct mem_section *ms) >>> pgdat_resize_lock(pgdat, &flags); >>> sparse_remove_one_section(zone, ms); >>> pgdat_resize_unlock(pgdat, &flags); >>> - return 0; >>> + >>> + return ret; >>> } >>> -#endif >>> >>> /* >>> * Reasonably generic function for adding memory. It is >>> diff --git a/mm/sparse.c b/mm/sparse.c >>> index fac95f2..ab9d755 100644 >>> --- a/mm/sparse.c >>> +++ b/mm/sparse.c >>> @@ -613,12 +613,13 @@ static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid, >>> /* This will make the necessary allocations eventually. */ >>> return sparse_mem_map_populate(pnum, nid); >>> } >>> -static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages) >>> +static void __kfree_section_memmap(struct page *page, unsigned long nr_pages) >>> { >>> - return; /* XXX: Not implemented yet */ >>> + vmemmap_kfree(page, nr_pages); >>> } >>> static void free_map_bootmem(struct page *page, unsigned long nr_pages) >>> { >>> + vmemmap_free_bootmem(page, nr_pages); >>> } >> >> Hi Congyang, >> For vmemmap, nr_pages should be PAGES_PER_SECTION for free_map_bootmem(), >> which is passed by free_section_usemap(), right? >> But now, nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page)) >> PAGE_SHIFT. >> >> Signed-off-by: Jianguo Wu <wujianguo@huawei.com> >> --- >> mm/sparse.c | 4 ++++ >> 1 files changed, 4 insertions(+), 0 deletions(-) >> >> diff --git a/mm/sparse.c b/mm/sparse.c >> index fac95f2..31e5282 100644 >> --- a/mm/sparse.c >> +++ b/mm/sparse.c >> @@ -713,8 +713,12 @@ static void free_section_usemap(struct page *memmap, unsigned long *usemap) >> struct page *memmap_page; >> memmap_page = virt_to_page(memmap); >> >> +#ifdef CONFIG_SPARSEMEM_VMEMMAP >> + nr_pages = PAGES_PER_SECTION; >> +#else >> nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page)) >> >> PAGE_SHIFT; >> +#endif > > Hmm, to avoid using ifdef, I think we can pass PAGE_PER_SECTION to free_map_bootmem(), > and calculate how many pages is used to store struct page. > yes, it is ugly to use ifdef. Or we can remove parameter--nr_pages of free_map_bootmem(), and calculate nr_pages in free_map_bootmem() directly. > Thanks > Wen Congyang > >> >> free_map_bootmem(memmap_page, nr_pages); >> } > > > . > -- To unsubscribe from this list: send the line "unsubscribe linux-sh" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/mm/sparse.c b/mm/sparse.c index fac95f2..31e5282 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -713,8 +713,12 @@ static void free_section_usemap(struct page *memmap, unsigned long *usemap) struct page *memmap_page; memmap_page = virt_to_page(memmap); +#ifdef CONFIG_SPARSEMEM_VMEMMAP + nr_pages = PAGES_PER_SECTION; +#else nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page)) >> PAGE_SHIFT; +#endif free_map_bootmem(memmap_page, nr_pages); }