| Message ID | 1346837155-534-17-git-send-email-wency@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 09/05/2012 05:25 PM, wency@cn.fujitsu.com 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: Benjamin Herrenschmidt <benh@kernel.crashing.org> > CC: Paul Mackerras <paulus@samba.org> > 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 3690c44..835a2b3 100644 > --- a/arch/powerpc/mm/init_64.c > +++ b/arch/powerpc/mm/init_64.c > @@ -299,6 +299,14 @@ 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 eda55cd..4b42b0b 100644 > --- a/arch/s390/mm/vmem.c > +++ b/arch/s390/mm/vmem.c > @@ -227,6 +227,14 @@ 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 add1cc7..1384826 100644 > --- a/arch/sparc/mm/init_64.c > +++ b/arch/sparc/mm/init_64.c > @@ -2078,6 +2078,14 @@ 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 0075592..4e8f8a4 100644 > --- a/arch/x86/mm/init_64.c > +++ b/arch/x86/mm/init_64.c > @@ -1138,6 +1138,125 @@ 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; > + 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; > + } > + Hi Yasuaki, why call memchr_inv check after memset, this time the page can always be filled with 0xFD. > + 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 c607913..fb0d1fc 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1620,6 +1620,8 @@ 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 647a7f2..c54922c 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -308,19 +308,6 @@ 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; > @@ -337,9 +324,9 @@ 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); > } > #else > static struct page *__kmalloc_section_memmap(unsigned long nr_pages) -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Chen, Sorry for late reply. 2012/10/02 13:21, Ni zhan Chen wrote: > On 09/05/2012 05:25 PM, wency@cn.fujitsu.com 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: Benjamin Herrenschmidt <benh@kernel.crashing.org> >> CC: Paul Mackerras <paulus@samba.org> >> 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 3690c44..835a2b3 100644 >> --- a/arch/powerpc/mm/init_64.c >> +++ b/arch/powerpc/mm/init_64.c >> @@ -299,6 +299,14 @@ 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 eda55cd..4b42b0b 100644 >> --- a/arch/s390/mm/vmem.c >> +++ b/arch/s390/mm/vmem.c >> @@ -227,6 +227,14 @@ 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 add1cc7..1384826 100644 >> --- a/arch/sparc/mm/init_64.c >> +++ b/arch/sparc/mm/init_64.c >> @@ -2078,6 +2078,14 @@ 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 0075592..4e8f8a4 100644 >> --- a/arch/x86/mm/init_64.c >> +++ b/arch/x86/mm/init_64.c >> @@ -1138,6 +1138,125 @@ 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; >> + 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; >> + } >> + > > Hi Yasuaki, > > why call memchr_inv check after memset, this time the page can always be filled with 0xFD. The page is not always filled with 0xFD. find_and_clear_pte_page() is calld in each section. So the function fills the page section size/sizeof(page) byte with 0xFD one time. Thus if section size is small, the page is filled with 0xFD. Thanks, Yasuaki Ishimatsu >> + 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 c607913..fb0d1fc 100644 >> --- a/include/linux/mm.h >> +++ b/include/linux/mm.h >> @@ -1620,6 +1620,8 @@ 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 647a7f2..c54922c 100644 >> --- a/mm/memory_hotplug.c >> +++ b/mm/memory_hotplug.c >> @@ -308,19 +308,6 @@ 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; >> @@ -337,9 +324,9 @@ 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); >> } >> #else >> static struct page *__kmalloc_section_memmap(unsigned long nr_pages) > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 10/04/2012 02:26 PM, Yasuaki Ishimatsu wrote: > Hi Chen, > > Sorry for late reply. > > 2012/10/02 13:21, Ni zhan Chen wrote: >> On 09/05/2012 05:25 PM, wency@cn.fujitsu.com 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: Benjamin Herrenschmidt <benh@kernel.crashing.org> >>> CC: Paul Mackerras <paulus@samba.org> >>> 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 3690c44..835a2b3 100644 >>> --- a/arch/powerpc/mm/init_64.c >>> +++ b/arch/powerpc/mm/init_64.c >>> @@ -299,6 +299,14 @@ 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 eda55cd..4b42b0b 100644 >>> --- a/arch/s390/mm/vmem.c >>> +++ b/arch/s390/mm/vmem.c >>> @@ -227,6 +227,14 @@ 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 add1cc7..1384826 100644 >>> --- a/arch/sparc/mm/init_64.c >>> +++ b/arch/sparc/mm/init_64.c >>> @@ -2078,6 +2078,14 @@ 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 0075592..4e8f8a4 100644 >>> --- a/arch/x86/mm/init_64.c >>> +++ b/arch/x86/mm/init_64.c >>> @@ -1138,6 +1138,125 @@ 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; >>> + 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; >>> + } >>> + >> >> Hi Yasuaki, >> >> why call memchr_inv check after memset, this time the page can always >> be filled with 0xFD. > > The page is not always filled with 0xFD. find_and_clear_pte_page() > is calld in each section. So the function fills the page > section size/sizeof(page) byte with 0xFD one time. Thus if section > size is > small, the page is filled with 0xFD. Hi Yasuaki, But when section size will be small? Regards, Chen > > Thanks, > Yasuaki Ishimatsu > > >>> + 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 c607913..fb0d1fc 100644 >>> --- a/include/linux/mm.h >>> +++ b/include/linux/mm.h >>> @@ -1620,6 +1620,8 @@ 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 647a7f2..c54922c 100644 >>> --- a/mm/memory_hotplug.c >>> +++ b/mm/memory_hotplug.c >>> @@ -308,19 +308,6 @@ 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; >>> @@ -337,9 +324,9 @@ 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); >>> } >>> #else >>> static struct page *__kmalloc_section_memmap(unsigned long nr_pages) >> > > > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" 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/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 3690c44..835a2b3 100644 --- a/arch/powerpc/mm/init_64.c +++ b/arch/powerpc/mm/init_64.c @@ -299,6 +299,14 @@ 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 eda55cd..4b42b0b 100644 --- a/arch/s390/mm/vmem.c +++ b/arch/s390/mm/vmem.c @@ -227,6 +227,14 @@ 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 add1cc7..1384826 100644 --- a/arch/sparc/mm/init_64.c +++ b/arch/sparc/mm/init_64.c @@ -2078,6 +2078,14 @@ 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 0075592..4e8f8a4 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1138,6 +1138,125 @@ 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; + 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 c607913..fb0d1fc 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1620,6 +1620,8 @@ 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 647a7f2..c54922c 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -308,19 +308,6 @@ 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; @@ -337,9 +324,9 @@ 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); } #else static struct page *__kmalloc_section_memmap(unsigned long nr_pages)