| Message ID | 5073DFC0.3010400@gmail.com |
|---|---|
| State | Not Applicable |
| Delegated to: | David Miller |
| Headers | show |
Hi, Wu Sorry for late reply. At 10/09/2012 04:26 PM, wujianguo Wrote: > Hi Congyang, > I think we should also free pages which are used by page tables after removing > page tables of the memory. It is OK to do it. > > From: Jianguo Wu <wujianguo@huawei.com> > > Signed-off-by: Jianguo Wu <wujianguo@huawei.com> > Signed-off-by: Jiang Liu <jiang.liu@huawei.com> > --- > arch/x86/mm/init_64.c | 110 +++++++++++++++++++++++++++++++++++++++--------- > 1 files changed, 89 insertions(+), 21 deletions(-) > > diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c > index 5596dfa..81f9c3b 100644 > --- a/arch/x86/mm/init_64.c > +++ b/arch/x86/mm/init_64.c > @@ -675,6 +675,74 @@ int arch_add_memory(int nid, u64 start, u64 size) > } > EXPORT_SYMBOL_GPL(arch_add_memory); > > +static inline void free_pagetable(struct page *page) > +{ > + struct zone *zone; > + > + __ClearPageReserved(page); > + __free_page(page); > + > + zone = page_zone(page); > + zone_span_writelock(zone); > + zone->present_pages++; > + zone_span_writeunlock(zone); > + totalram_pages++; Why do you update zone and totalram_pages here? > +} > + > +static void free_pte_table(pte_t *pte_start, pmd_t *pmd) > +{ > + pte_t *pte; > + int i; > + > + for (i = 0; i < PTRS_PER_PTE; i++) { > + pte = pte_start + i; > + if (pte_val(*pte)) > + break; > + } > + > + /* free a pte talbe */ > + if (i == PTRS_PER_PTE) { > + free_pagetable(pmd_page(*pmd)); The memory may be allocated at booting. So it is very dangerous to free it without any check. > + pmd_clear(pmd); > + } > +} > + > +static void free_pmd_table(pmd_t *pmd_start, pud_t *pud) > +{ > + pmd_t *pmd; > + int i; > + > + for (i = 0; i < PTRS_PER_PMD; i++) { > + pmd = pmd_start + i; > + if (pmd_val(*pmd)) > + break; > + } > + > + /* free a pmd talbe */ > + if (i == PTRS_PER_PMD) { > + free_pagetable(pud_page(*pud)); > + pud_clear(pud); > + } > +} > + > +static void free_pud_table(pud_t *pud_start, pgd_t *pgd) > +{ > + pud_t *pud; > + int i; > + > + for (i = 0; i < PTRS_PER_PUD; i++) { > + pud = pud_start + i; > + if (pud_val(*pud)) > + break; > + } > + > + /* free a pud table */ > + if (i == PTRS_PER_PUD) { > + free_pagetable(pgd_page(*pgd)); > + pgd_clear(pgd); > + } > +} > + > static void __meminit > phys_pte_remove(pte_t *pte_page, unsigned long addr, unsigned long end) > { > @@ -704,21 +772,19 @@ phys_pmd_remove(pmd_t *pmd_page, unsigned long addr, unsigned long end) > unsigned long pages = 0, next; > int i = pmd_index(addr); > > - for (; i < PTRS_PER_PMD; i++, addr = next) { > + for (; i < PTRS_PER_PMD && addr < end; i++, addr = next) { > unsigned long pte_phys; > pmd_t *pmd = pmd_page + pmd_index(addr); > pte_t *pte; > > - if (addr >= end) > - break; > - > - next = (addr & PMD_MASK) + PMD_SIZE; > + next = pmd_addr_end(addr, end); > > if (!pmd_present(*pmd)) > continue; > > if (pmd_large(*pmd)) { > - if ((addr & ~PMD_MASK) == 0 && next <= end) { > + if (IS_ALIGNED(addr, PMD_SIZE) && > + IS_ALIGNED(next, PMD_SIZE)) { > set_pmd(pmd, __pmd(0)); > pages++; > continue; > @@ -729,7 +795,8 @@ phys_pmd_remove(pmd_t *pmd_page, unsigned long addr, unsigned long end) > * so split 2M page to 4K page. > */ > pte = alloc_low_page(&pte_phys); > - __split_large_page((pte_t *)pmd, addr, pte); > + __split_large_page((pte_t *)pmd, > + (unsigned long)__va(addr), pte); > > spin_lock(&init_mm.page_table_lock); > pmd_populate_kernel(&init_mm, pmd, __va(pte_phys)); > @@ -738,7 +805,8 @@ phys_pmd_remove(pmd_t *pmd_page, unsigned long addr, unsigned long end) > > spin_lock(&init_mm.page_table_lock); > pte = map_low_page((pte_t *)pmd_page_vaddr(*pmd)); > - phys_pte_remove(pte, addr, end); > + phys_pte_remove(pte, addr, next); > + free_pte_table(pte, pmd); > unmap_low_page(pte); > spin_unlock(&init_mm.page_table_lock); > } > @@ -751,21 +819,19 @@ phys_pud_remove(pud_t *pud_page, unsigned long addr, unsigned long end) > unsigned long pages = 0, next; > int i = pud_index(addr); > > - for (; i < PTRS_PER_PUD; i++, addr = next) { > + for (; i < PTRS_PER_PUD && addr < end; i++, addr = next) { > unsigned long pmd_phys; > pud_t *pud = pud_page + pud_index(addr); > pmd_t *pmd; > > - if (addr >= end) > - break; > - > - next = (addr & PUD_MASK) + PUD_SIZE; > + next = pud_addr_end(addr, end); > > if (!pud_present(*pud)) > continue; > > if (pud_large(*pud)) { > - if ((addr & ~PUD_MASK) == 0 && next <= end) { > + if (IS_ALIGNED(addr, PUD_SIZE) && > + IS_ALIGNED(next, PUD_SIZE)) { > set_pud(pud, __pud(0)); > pages++; > continue; > @@ -776,15 +842,18 @@ phys_pud_remove(pud_t *pud_page, unsigned long addr, unsigned long end) > * so split 1G page to 2M page. > */ > pmd = alloc_low_page(&pmd_phys); > - __split_large_page((pte_t *)pud, addr, (pte_t *)pmd); > + __split_large_page((pte_t *)pud, > + (unsigned long)__va(addr), > + (pte_t *)pmd); > > spin_lock(&init_mm.page_table_lock); > pud_populate(&init_mm, pud, __va(pmd_phys)); > spin_unlock(&init_mm.page_table_lock); > } > > - pmd = map_low_page(pmd_offset(pud, 0)); > - phys_pmd_remove(pmd, addr, end); > + pmd = map_low_page((pmd_t *)pud_page_vaddr(*pud)); Hmm, pmd_offset(pud, 0) is equal to (pmd_t *)pud_page_vaddr(*pud). Is it OK to merge your patch into my patch? Thanks Wen Congyang > + phys_pmd_remove(pmd, addr, next); > + free_pmd_table(pmd, pud); > unmap_low_page(pmd); > __flush_tlb_all(); > } > @@ -805,15 +874,14 @@ kernel_physical_mapping_remove(unsigned long start, unsigned long end) > pgd_t *pgd = pgd_offset_k(start); > pud_t *pud; > > - next = (start + PGDIR_SIZE) & PGDIR_MASK; > - if (next > end) > - next = end; > + next = pgd_addr_end(start, end); > > if (!pgd_present(*pgd)) > continue; > > pud = map_low_page((pud_t *)pgd_page_vaddr(*pgd)); > - phys_pud_remove(pud, __pa(start), __pa(end)); > + phys_pud_remove(pud, __pa(start), __pa(next)); > + free_pud_table(pud, pgd); > unmap_low_page(pud); > } > > -- 1.7.6.1 . > > > On 2012-10-5 10:36, Yasuaki Ishimatsu wrote: >> From: Wen Congyang <wency@cn.fujitsu.com> >> >> For hot removing memory, we sholud remove page table about the memory. >> So the patch searches a page table about the removed memory, and clear >> page table. >> >> 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: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> >> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> >> --- >> arch/x86/include/asm/pgtable_types.h | 1 >> arch/x86/mm/init_64.c | 147 +++++++++++++++++++++++++++++++++++ >> arch/x86/mm/pageattr.c | 47 +++++------ >> 3 files changed, 173 insertions(+), 22 deletions(-) >> >> Index: linux-3.6/arch/x86/mm/init_64.c >> =================================================================== >> --- linux-3.6.orig/arch/x86/mm/init_64.c 2012-10-04 18:30:21.171698416 +0900 >> +++ linux-3.6/arch/x86/mm/init_64.c 2012-10-04 18:30:27.317704652 +0900 >> @@ -675,6 +675,151 @@ int arch_add_memory(int nid, u64 start, >> } >> EXPORT_SYMBOL_GPL(arch_add_memory); >> >> +static void __meminit >> +phys_pte_remove(pte_t *pte_page, unsigned long addr, unsigned long end) >> +{ >> + unsigned pages = 0; >> + int i = pte_index(addr); >> + >> + pte_t *pte = pte_page + pte_index(addr); >> + >> + for (; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) { >> + >> + if (addr >= end) >> + break; >> + >> + if (!pte_present(*pte)) >> + continue; >> + >> + pages++; >> + set_pte(pte, __pte(0)); >> + } >> + >> + update_page_count(PG_LEVEL_4K, -pages); >> +} >> + >> +static void __meminit >> +phys_pmd_remove(pmd_t *pmd_page, unsigned long addr, unsigned long end) >> +{ >> + unsigned long pages = 0, next; >> + int i = pmd_index(addr); >> + >> + for (; i < PTRS_PER_PMD; i++, addr = next) { >> + unsigned long pte_phys; >> + pmd_t *pmd = pmd_page + pmd_index(addr); >> + pte_t *pte; >> + >> + if (addr >= end) >> + break; >> + >> + next = (addr & PMD_MASK) + PMD_SIZE; >> + >> + if (!pmd_present(*pmd)) >> + continue; >> + >> + if (pmd_large(*pmd)) { >> + if ((addr & ~PMD_MASK) == 0 && next <= end) { >> + set_pmd(pmd, __pmd(0)); >> + pages++; >> + continue; >> + } >> + >> + /* >> + * We use 2M page, but we need to remove part of them, >> + * so split 2M page to 4K page. >> + */ >> + pte = alloc_low_page(&pte_phys); >> + __split_large_page((pte_t *)pmd, addr, pte); >> + >> + spin_lock(&init_mm.page_table_lock); >> + pmd_populate_kernel(&init_mm, pmd, __va(pte_phys)); >> + spin_unlock(&init_mm.page_table_lock); >> + } >> + >> + spin_lock(&init_mm.page_table_lock); >> + pte = map_low_page((pte_t *)pmd_page_vaddr(*pmd)); >> + phys_pte_remove(pte, addr, end); >> + unmap_low_page(pte); >> + spin_unlock(&init_mm.page_table_lock); >> + } >> + update_page_count(PG_LEVEL_2M, -pages); >> +} >> + >> +static void __meminit >> +phys_pud_remove(pud_t *pud_page, unsigned long addr, unsigned long end) >> +{ >> + unsigned long pages = 0, next; >> + int i = pud_index(addr); >> + >> + for (; i < PTRS_PER_PUD; i++, addr = next) { >> + unsigned long pmd_phys; >> + pud_t *pud = pud_page + pud_index(addr); >> + pmd_t *pmd; >> + >> + if (addr >= end) >> + break; >> + >> + next = (addr & PUD_MASK) + PUD_SIZE; >> + >> + if (!pud_present(*pud)) >> + continue; >> + >> + if (pud_large(*pud)) { >> + if ((addr & ~PUD_MASK) == 0 && next <= end) { >> + set_pud(pud, __pud(0)); >> + pages++; >> + continue; >> + } >> + >> + /* >> + * We use 1G page, but we need to remove part of them, >> + * so split 1G page to 2M page. >> + */ >> + pmd = alloc_low_page(&pmd_phys); >> + __split_large_page((pte_t *)pud, addr, (pte_t *)pmd); >> + >> + spin_lock(&init_mm.page_table_lock); >> + pud_populate(&init_mm, pud, __va(pmd_phys)); >> + spin_unlock(&init_mm.page_table_lock); >> + } >> + >> + pmd = map_low_page(pmd_offset(pud, 0)); >> + phys_pmd_remove(pmd, addr, end); >> + unmap_low_page(pmd); >> + __flush_tlb_all(); >> + } >> + __flush_tlb_all(); >> + >> + update_page_count(PG_LEVEL_1G, -pages); >> +} >> + >> +void __meminit >> +kernel_physical_mapping_remove(unsigned long start, unsigned long end) >> +{ >> + unsigned long next; >> + >> + start = (unsigned long)__va(start); >> + end = (unsigned long)__va(end); >> + >> + for (; start < end; start = next) { >> + pgd_t *pgd = pgd_offset_k(start); >> + pud_t *pud; >> + >> + next = (start + PGDIR_SIZE) & PGDIR_MASK; >> + if (next > end) >> + next = end; >> + >> + if (!pgd_present(*pgd)) >> + continue; >> + >> + pud = map_low_page((pud_t *)pgd_page_vaddr(*pgd)); >> + phys_pud_remove(pud, __pa(start), __pa(end)); >> + unmap_low_page(pud); >> + } >> + >> + __flush_tlb_all(); >> +} >> + >> #ifdef CONFIG_MEMORY_HOTREMOVE >> int __ref arch_remove_memory(u64 start, u64 size) >> { >> @@ -687,6 +832,8 @@ int __ref arch_remove_memory(u64 start, >> ret = __remove_pages(zone, start_pfn, nr_pages); >> WARN_ON_ONCE(ret); >> >> + kernel_physical_mapping_remove(start, start + size); >> + >> return ret; >> } >> #endif >> Index: linux-3.6/arch/x86/include/asm/pgtable_types.h >> =================================================================== >> --- linux-3.6.orig/arch/x86/include/asm/pgtable_types.h 2012-10-04 18:26:51.925486954 +0900 >> +++ linux-3.6/arch/x86/include/asm/pgtable_types.h 2012-10-04 18:30:27.322704656 +0900 >> @@ -334,6 +334,7 @@ static inline void update_page_count(int >> * as a pte too. >> */ >> extern pte_t *lookup_address(unsigned long address, unsigned int *level); >> +extern int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase); >> >> #endif /* !__ASSEMBLY__ */ >> >> Index: linux-3.6/arch/x86/mm/pageattr.c >> =================================================================== >> --- linux-3.6.orig/arch/x86/mm/pageattr.c 2012-10-04 18:26:51.923486952 +0900 >> +++ linux-3.6/arch/x86/mm/pageattr.c 2012-10-04 18:30:27.328704662 +0900 >> @@ -501,21 +501,13 @@ out_unlock: >> return do_split; >> } >> >> -static int split_large_page(pte_t *kpte, unsigned long address) >> +int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase) >> { >> unsigned long pfn, pfninc = 1; >> unsigned int i, level; >> - pte_t *pbase, *tmp; >> + pte_t *tmp; >> pgprot_t ref_prot; >> - struct page *base; >> - >> - if (!debug_pagealloc) >> - spin_unlock(&cpa_lock); >> - base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0); >> - if (!debug_pagealloc) >> - spin_lock(&cpa_lock); >> - if (!base) >> - return -ENOMEM; >> + struct page *base = virt_to_page(pbase); >> >> spin_lock(&pgd_lock); >> /* >> @@ -523,10 +515,11 @@ static int split_large_page(pte_t *kpte, >> * up for us already: >> */ >> tmp = lookup_address(address, &level); >> - if (tmp != kpte) >> - goto out_unlock; >> + if (tmp != kpte) { >> + spin_unlock(&pgd_lock); >> + return 1; >> + } >> >> - pbase = (pte_t *)page_address(base); >> paravirt_alloc_pte(&init_mm, page_to_pfn(base)); >> ref_prot = pte_pgprot(pte_clrhuge(*kpte)); >> /* >> @@ -579,17 +572,27 @@ static int split_large_page(pte_t *kpte, >> * going on. >> */ >> __flush_tlb_all(); >> + spin_unlock(&pgd_lock); >> >> - base = NULL; >> + return 0; >> +} >> >> -out_unlock: >> - /* >> - * If we dropped out via the lookup_address check under >> - * pgd_lock then stick the page back into the pool: >> - */ >> - if (base) >> +static int split_large_page(pte_t *kpte, unsigned long address) >> +{ >> + pte_t *pbase; >> + struct page *base; >> + >> + if (!debug_pagealloc) >> + spin_unlock(&cpa_lock); >> + base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0); >> + if (!debug_pagealloc) >> + spin_lock(&cpa_lock); >> + if (!base) >> + return -ENOMEM; >> + >> + pbase = (pte_t *)page_address(base); >> + if (__split_large_page(kpte, address, pbase)) >> __free_page(base); >> - spin_unlock(&pgd_lock); >> >> return 0; >> } >> >> -- >> To unsubscribe, send a message with 'unsubscribe linux-mm' in >> the body to majordomo@kvack.org. For more info on Linux MM, >> see: http://www.linux-mm.org/ . >> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> >> > > -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2012-10-22 15:11, Wen Congyang wrote: > Hi, Wu > > Sorry for late reply. > > At 10/09/2012 04:26 PM, wujianguo Wrote: >> Hi Congyang, >> I think we should also free pages which are used by page tables after removing >> page tables of the memory. > > It is OK to do it. > >> >> From: Jianguo Wu <wujianguo@huawei.com> >> >> Signed-off-by: Jianguo Wu <wujianguo@huawei.com> >> Signed-off-by: Jiang Liu <jiang.liu@huawei.com> >> --- >> arch/x86/mm/init_64.c | 110 +++++++++++++++++++++++++++++++++++++++--------- >> 1 files changed, 89 insertions(+), 21 deletions(-) >> >> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c >> index 5596dfa..81f9c3b 100644 >> --- a/arch/x86/mm/init_64.c >> +++ b/arch/x86/mm/init_64.c >> @@ -675,6 +675,74 @@ int arch_add_memory(int nid, u64 start, u64 size) >> } >> EXPORT_SYMBOL_GPL(arch_add_memory); >> >> +static inline void free_pagetable(struct page *page) >> +{ >> + struct zone *zone; >> + >> + __ClearPageReserved(page); >> + __free_page(page); >> + >> + zone = page_zone(page); >> + zone_span_writelock(zone); >> + zone->present_pages++; >> + zone_span_writeunlock(zone); >> + totalram_pages++; > > Why do you update zone and totalram_pages here? Sorry, I made a mistake here. Only if the page was allocated at booting, we should update zone and totalram_pages(zone->present_pages and totalram_pages mean pages which are managed by buddy system). How about: static inline void free_pagetable(struct page *page) { struct zone *zone; bool bootmem = false; /* bootmem page has reserved flag */ if (PageReserved(page)) { __ClearPageReserved(page); bootmem = true; } __free_page(page); if (bootmem) { zone = page_zone(page); zone_span_writelock(zone); zone->present_pages++; zone_span_writeunlock(zone); totalram_pages++; } } > >> +} >> + >> +static void free_pte_table(pte_t *pte_start, pmd_t *pmd) >> +{ >> + pte_t *pte; >> + int i; >> + >> + for (i = 0; i < PTRS_PER_PTE; i++) { >> + pte = pte_start + i; >> + if (pte_val(*pte)) >> + break; >> + } >> + >> + /* free a pte talbe */ >> + if (i == PTRS_PER_PTE) { >> + free_pagetable(pmd_page(*pmd)); > > The memory may be allocated at booting. So it is very dangerous to > free it without any check. The page is only used by page table, so is safe to free it when all the page table entries have been cleared, right? > >> + pmd_clear(pmd); >> + } >> +} >> + >> +static void free_pmd_table(pmd_t *pmd_start, pud_t *pud) >> +{ >> + pmd_t *pmd; >> + int i; >> + >> + for (i = 0; i < PTRS_PER_PMD; i++) { >> + pmd = pmd_start + i; >> + if (pmd_val(*pmd)) >> + break; >> + } >> + >> + /* free a pmd talbe */ >> + if (i == PTRS_PER_PMD) { >> + free_pagetable(pud_page(*pud)); >> + pud_clear(pud); >> + } >> +} >> + >> +static void free_pud_table(pud_t *pud_start, pgd_t *pgd) >> +{ >> + pud_t *pud; >> + int i; >> + >> + for (i = 0; i < PTRS_PER_PUD; i++) { >> + pud = pud_start + i; >> + if (pud_val(*pud)) >> + break; >> + } >> + >> + /* free a pud table */ >> + if (i == PTRS_PER_PUD) { >> + free_pagetable(pgd_page(*pgd)); >> + pgd_clear(pgd); >> + } >> +} >> + >> static void __meminit >> phys_pte_remove(pte_t *pte_page, unsigned long addr, unsigned long end) >> { >> @@ -704,21 +772,19 @@ phys_pmd_remove(pmd_t *pmd_page, unsigned long addr, unsigned long end) >> unsigned long pages = 0, next; >> int i = pmd_index(addr); >> >> - for (; i < PTRS_PER_PMD; i++, addr = next) { >> + for (; i < PTRS_PER_PMD && addr < end; i++, addr = next) { >> unsigned long pte_phys; >> pmd_t *pmd = pmd_page + pmd_index(addr); >> pte_t *pte; >> >> - if (addr >= end) >> - break; >> - >> - next = (addr & PMD_MASK) + PMD_SIZE; >> + next = pmd_addr_end(addr, end); >> >> if (!pmd_present(*pmd)) >> continue; >> >> if (pmd_large(*pmd)) { >> - if ((addr & ~PMD_MASK) == 0 && next <= end) { >> + if (IS_ALIGNED(addr, PMD_SIZE) && >> + IS_ALIGNED(next, PMD_SIZE)) { >> set_pmd(pmd, __pmd(0)); >> pages++; >> continue; >> @@ -729,7 +795,8 @@ phys_pmd_remove(pmd_t *pmd_page, unsigned long addr, unsigned long end) >> * so split 2M page to 4K page. >> */ >> pte = alloc_low_page(&pte_phys); >> - __split_large_page((pte_t *)pmd, addr, pte); >> + __split_large_page((pte_t *)pmd, >> + (unsigned long)__va(addr), pte); >> >> spin_lock(&init_mm.page_table_lock); >> pmd_populate_kernel(&init_mm, pmd, __va(pte_phys)); >> @@ -738,7 +805,8 @@ phys_pmd_remove(pmd_t *pmd_page, unsigned long addr, unsigned long end) >> >> spin_lock(&init_mm.page_table_lock); >> pte = map_low_page((pte_t *)pmd_page_vaddr(*pmd)); >> - phys_pte_remove(pte, addr, end); >> + phys_pte_remove(pte, addr, next); >> + free_pte_table(pte, pmd); >> unmap_low_page(pte); >> spin_unlock(&init_mm.page_table_lock); >> } >> @@ -751,21 +819,19 @@ phys_pud_remove(pud_t *pud_page, unsigned long addr, unsigned long end) >> unsigned long pages = 0, next; >> int i = pud_index(addr); >> >> - for (; i < PTRS_PER_PUD; i++, addr = next) { >> + for (; i < PTRS_PER_PUD && addr < end; i++, addr = next) { >> unsigned long pmd_phys; >> pud_t *pud = pud_page + pud_index(addr); >> pmd_t *pmd; >> >> - if (addr >= end) >> - break; >> - >> - next = (addr & PUD_MASK) + PUD_SIZE; >> + next = pud_addr_end(addr, end); >> >> if (!pud_present(*pud)) >> continue; >> >> if (pud_large(*pud)) { >> - if ((addr & ~PUD_MASK) == 0 && next <= end) { >> + if (IS_ALIGNED(addr, PUD_SIZE) && >> + IS_ALIGNED(next, PUD_SIZE)) { >> set_pud(pud, __pud(0)); >> pages++; >> continue; >> @@ -776,15 +842,18 @@ phys_pud_remove(pud_t *pud_page, unsigned long addr, unsigned long end) >> * so split 1G page to 2M page. >> */ >> pmd = alloc_low_page(&pmd_phys); >> - __split_large_page((pte_t *)pud, addr, (pte_t *)pmd); >> + __split_large_page((pte_t *)pud, >> + (unsigned long)__va(addr), >> + (pte_t *)pmd); >> >> spin_lock(&init_mm.page_table_lock); >> pud_populate(&init_mm, pud, __va(pmd_phys)); >> spin_unlock(&init_mm.page_table_lock); >> } >> >> - pmd = map_low_page(pmd_offset(pud, 0)); >> - phys_pmd_remove(pmd, addr, end); >> + pmd = map_low_page((pmd_t *)pud_page_vaddr(*pud)); > > Hmm, pmd_offset(pud, 0) is equal to (pmd_t *)pud_page_vaddr(*pud). > > Is it OK to merge your patch into my patch? > Yes, sure. Thanks, Jianguo Wu > Thanks > Wen Congyang > >> + phys_pmd_remove(pmd, addr, next); >> + free_pmd_table(pmd, pud); >> unmap_low_page(pmd); >> __flush_tlb_all(); >> } >> @@ -805,15 +874,14 @@ kernel_physical_mapping_remove(unsigned long start, unsigned long end) >> pgd_t *pgd = pgd_offset_k(start); >> pud_t *pud; >> >> - next = (start + PGDIR_SIZE) & PGDIR_MASK; >> - if (next > end) >> - next = end; >> + next = pgd_addr_end(start, end); >> >> if (!pgd_present(*pgd)) >> continue; >> >> pud = map_low_page((pud_t *)pgd_page_vaddr(*pgd)); >> - phys_pud_remove(pud, __pa(start), __pa(end)); >> + phys_pud_remove(pud, __pa(start), __pa(next)); >> + free_pud_table(pud, pgd); >> unmap_low_page(pud); >> } >> >> -- 1.7.6.1 . >> >> >> On 2012-10-5 10:36, Yasuaki Ishimatsu wrote: >>> From: Wen Congyang <wency@cn.fujitsu.com> >>> >>> For hot removing memory, we sholud remove page table about the memory. >>> So the patch searches a page table about the removed memory, and clear >>> page table. >>> >>> 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: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> >>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> >>> --- >>> arch/x86/include/asm/pgtable_types.h | 1 >>> arch/x86/mm/init_64.c | 147 +++++++++++++++++++++++++++++++++++ >>> arch/x86/mm/pageattr.c | 47 +++++------ >>> 3 files changed, 173 insertions(+), 22 deletions(-) >>> >>> Index: linux-3.6/arch/x86/mm/init_64.c >>> =================================================================== >>> --- linux-3.6.orig/arch/x86/mm/init_64.c 2012-10-04 18:30:21.171698416 +0900 >>> +++ linux-3.6/arch/x86/mm/init_64.c 2012-10-04 18:30:27.317704652 +0900 >>> @@ -675,6 +675,151 @@ int arch_add_memory(int nid, u64 start, >>> } >>> EXPORT_SYMBOL_GPL(arch_add_memory); >>> >>> +static void __meminit >>> +phys_pte_remove(pte_t *pte_page, unsigned long addr, unsigned long end) >>> +{ >>> + unsigned pages = 0; >>> + int i = pte_index(addr); >>> + >>> + pte_t *pte = pte_page + pte_index(addr); >>> + >>> + for (; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) { >>> + >>> + if (addr >= end) >>> + break; >>> + >>> + if (!pte_present(*pte)) >>> + continue; >>> + >>> + pages++; >>> + set_pte(pte, __pte(0)); >>> + } >>> + >>> + update_page_count(PG_LEVEL_4K, -pages); >>> +} >>> + >>> +static void __meminit >>> +phys_pmd_remove(pmd_t *pmd_page, unsigned long addr, unsigned long end) >>> +{ >>> + unsigned long pages = 0, next; >>> + int i = pmd_index(addr); >>> + >>> + for (; i < PTRS_PER_PMD; i++, addr = next) { >>> + unsigned long pte_phys; >>> + pmd_t *pmd = pmd_page + pmd_index(addr); >>> + pte_t *pte; >>> + >>> + if (addr >= end) >>> + break; >>> + >>> + next = (addr & PMD_MASK) + PMD_SIZE; >>> + >>> + if (!pmd_present(*pmd)) >>> + continue; >>> + >>> + if (pmd_large(*pmd)) { >>> + if ((addr & ~PMD_MASK) == 0 && next <= end) { >>> + set_pmd(pmd, __pmd(0)); >>> + pages++; >>> + continue; >>> + } >>> + >>> + /* >>> + * We use 2M page, but we need to remove part of them, >>> + * so split 2M page to 4K page. >>> + */ >>> + pte = alloc_low_page(&pte_phys); >>> + __split_large_page((pte_t *)pmd, addr, pte); >>> + >>> + spin_lock(&init_mm.page_table_lock); >>> + pmd_populate_kernel(&init_mm, pmd, __va(pte_phys)); >>> + spin_unlock(&init_mm.page_table_lock); >>> + } >>> + >>> + spin_lock(&init_mm.page_table_lock); >>> + pte = map_low_page((pte_t *)pmd_page_vaddr(*pmd)); >>> + phys_pte_remove(pte, addr, end); >>> + unmap_low_page(pte); >>> + spin_unlock(&init_mm.page_table_lock); >>> + } >>> + update_page_count(PG_LEVEL_2M, -pages); >>> +} >>> + >>> +static void __meminit >>> +phys_pud_remove(pud_t *pud_page, unsigned long addr, unsigned long end) >>> +{ >>> + unsigned long pages = 0, next; >>> + int i = pud_index(addr); >>> + >>> + for (; i < PTRS_PER_PUD; i++, addr = next) { >>> + unsigned long pmd_phys; >>> + pud_t *pud = pud_page + pud_index(addr); >>> + pmd_t *pmd; >>> + >>> + if (addr >= end) >>> + break; >>> + >>> + next = (addr & PUD_MASK) + PUD_SIZE; >>> + >>> + if (!pud_present(*pud)) >>> + continue; >>> + >>> + if (pud_large(*pud)) { >>> + if ((addr & ~PUD_MASK) == 0 && next <= end) { >>> + set_pud(pud, __pud(0)); >>> + pages++; >>> + continue; >>> + } >>> + >>> + /* >>> + * We use 1G page, but we need to remove part of them, >>> + * so split 1G page to 2M page. >>> + */ >>> + pmd = alloc_low_page(&pmd_phys); >>> + __split_large_page((pte_t *)pud, addr, (pte_t *)pmd); >>> + >>> + spin_lock(&init_mm.page_table_lock); >>> + pud_populate(&init_mm, pud, __va(pmd_phys)); >>> + spin_unlock(&init_mm.page_table_lock); >>> + } >>> + >>> + pmd = map_low_page(pmd_offset(pud, 0)); >>> + phys_pmd_remove(pmd, addr, end); >>> + unmap_low_page(pmd); >>> + __flush_tlb_all(); >>> + } >>> + __flush_tlb_all(); >>> + >>> + update_page_count(PG_LEVEL_1G, -pages); >>> +} >>> + >>> +void __meminit >>> +kernel_physical_mapping_remove(unsigned long start, unsigned long end) >>> +{ >>> + unsigned long next; >>> + >>> + start = (unsigned long)__va(start); >>> + end = (unsigned long)__va(end); >>> + >>> + for (; start < end; start = next) { >>> + pgd_t *pgd = pgd_offset_k(start); >>> + pud_t *pud; >>> + >>> + next = (start + PGDIR_SIZE) & PGDIR_MASK; >>> + if (next > end) >>> + next = end; >>> + >>> + if (!pgd_present(*pgd)) >>> + continue; >>> + >>> + pud = map_low_page((pud_t *)pgd_page_vaddr(*pgd)); >>> + phys_pud_remove(pud, __pa(start), __pa(end)); >>> + unmap_low_page(pud); >>> + } >>> + >>> + __flush_tlb_all(); >>> +} >>> + >>> #ifdef CONFIG_MEMORY_HOTREMOVE >>> int __ref arch_remove_memory(u64 start, u64 size) >>> { >>> @@ -687,6 +832,8 @@ int __ref arch_remove_memory(u64 start, >>> ret = __remove_pages(zone, start_pfn, nr_pages); >>> WARN_ON_ONCE(ret); >>> >>> + kernel_physical_mapping_remove(start, start + size); >>> + >>> return ret; >>> } >>> #endif >>> Index: linux-3.6/arch/x86/include/asm/pgtable_types.h >>> =================================================================== >>> --- linux-3.6.orig/arch/x86/include/asm/pgtable_types.h 2012-10-04 18:26:51.925486954 +0900 >>> +++ linux-3.6/arch/x86/include/asm/pgtable_types.h 2012-10-04 18:30:27.322704656 +0900 >>> @@ -334,6 +334,7 @@ static inline void update_page_count(int >>> * as a pte too. >>> */ >>> extern pte_t *lookup_address(unsigned long address, unsigned int *level); >>> +extern int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase); >>> >>> #endif /* !__ASSEMBLY__ */ >>> >>> Index: linux-3.6/arch/x86/mm/pageattr.c >>> =================================================================== >>> --- linux-3.6.orig/arch/x86/mm/pageattr.c 2012-10-04 18:26:51.923486952 +0900 >>> +++ linux-3.6/arch/x86/mm/pageattr.c 2012-10-04 18:30:27.328704662 +0900 >>> @@ -501,21 +501,13 @@ out_unlock: >>> return do_split; >>> } >>> >>> -static int split_large_page(pte_t *kpte, unsigned long address) >>> +int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase) >>> { >>> unsigned long pfn, pfninc = 1; >>> unsigned int i, level; >>> - pte_t *pbase, *tmp; >>> + pte_t *tmp; >>> pgprot_t ref_prot; >>> - struct page *base; >>> - >>> - if (!debug_pagealloc) >>> - spin_unlock(&cpa_lock); >>> - base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0); >>> - if (!debug_pagealloc) >>> - spin_lock(&cpa_lock); >>> - if (!base) >>> - return -ENOMEM; >>> + struct page *base = virt_to_page(pbase); >>> >>> spin_lock(&pgd_lock); >>> /* >>> @@ -523,10 +515,11 @@ static int split_large_page(pte_t *kpte, >>> * up for us already: >>> */ >>> tmp = lookup_address(address, &level); >>> - if (tmp != kpte) >>> - goto out_unlock; >>> + if (tmp != kpte) { >>> + spin_unlock(&pgd_lock); >>> + return 1; >>> + } >>> >>> - pbase = (pte_t *)page_address(base); >>> paravirt_alloc_pte(&init_mm, page_to_pfn(base)); >>> ref_prot = pte_pgprot(pte_clrhuge(*kpte)); >>> /* >>> @@ -579,17 +572,27 @@ static int split_large_page(pte_t *kpte, >>> * going on. >>> */ >>> __flush_tlb_all(); >>> + spin_unlock(&pgd_lock); >>> >>> - base = NULL; >>> + return 0; >>> +} >>> >>> -out_unlock: >>> - /* >>> - * If we dropped out via the lookup_address check under >>> - * pgd_lock then stick the page back into the pool: >>> - */ >>> - if (base) >>> +static int split_large_page(pte_t *kpte, unsigned long address) >>> +{ >>> + pte_t *pbase; >>> + struct page *base; >>> + >>> + if (!debug_pagealloc) >>> + spin_unlock(&cpa_lock); >>> + base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0); >>> + if (!debug_pagealloc) >>> + spin_lock(&cpa_lock); >>> + if (!base) >>> + return -ENOMEM; >>> + >>> + pbase = (pte_t *)page_address(base); >>> + if (__split_large_page(kpte, address, pbase)) >>> __free_page(base); >>> - spin_unlock(&pgd_lock); >>> >>> return 0; >>> } >>> >>> -- >>> To unsubscribe, send a message with 'unsubscribe linux-mm' in >>> the body to majordomo@kvack.org. For more info on Linux MM, >>> see: http://www.linux-mm.org/ . >>> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> >>> >> >> > > -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
At 10/23/2012 03:09 PM, wujianguo Wrote: > On 2012-10-22 15:11, Wen Congyang wrote: >> Hi, Wu >> >> Sorry for late reply. >> >> At 10/09/2012 04:26 PM, wujianguo Wrote: >>> Hi Congyang, >>> I think we should also free pages which are used by page tables after removing >>> page tables of the memory. >> >> It is OK to do it. >> >>> >>> From: Jianguo Wu <wujianguo@huawei.com> >>> >>> Signed-off-by: Jianguo Wu <wujianguo@huawei.com> >>> Signed-off-by: Jiang Liu <jiang.liu@huawei.com> >>> --- >>> arch/x86/mm/init_64.c | 110 +++++++++++++++++++++++++++++++++++++++--------- >>> 1 files changed, 89 insertions(+), 21 deletions(-) >>> >>> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c >>> index 5596dfa..81f9c3b 100644 >>> --- a/arch/x86/mm/init_64.c >>> +++ b/arch/x86/mm/init_64.c >>> @@ -675,6 +675,74 @@ int arch_add_memory(int nid, u64 start, u64 size) >>> } >>> EXPORT_SYMBOL_GPL(arch_add_memory); >>> >>> +static inline void free_pagetable(struct page *page) >>> +{ >>> + struct zone *zone; >>> + >>> + __ClearPageReserved(page); >>> + __free_page(page); >>> + >>> + zone = page_zone(page); >>> + zone_span_writelock(zone); >>> + zone->present_pages++; >>> + zone_span_writeunlock(zone); >>> + totalram_pages++; >> >> Why do you update zone and totalram_pages here? > Sorry, I made a mistake here. Only if the page was allocated at booting, we should update > zone and totalram_pages(zone->present_pages and totalram_pages mean pages which are > managed by buddy system). > > How about: > static inline void free_pagetable(struct page *page) > { > struct zone *zone; > bool bootmem = false; > > /* bootmem page has reserved flag */ > if (PageReserved(page)) { > __ClearPageReserved(page); > bootmem = true; > } > > __free_page(page); > > if (bootmem) { > zone = page_zone(page); > zone_span_writelock(zone); > zone->present_pages++; > zone_span_writeunlock(zone); > totalram_pages++; > } > } This verson looks fine to me. > >> >>> +} >>> + >>> +static void free_pte_table(pte_t *pte_start, pmd_t *pmd) >>> +{ >>> + pte_t *pte; >>> + int i; >>> + >>> + for (i = 0; i < PTRS_PER_PTE; i++) { >>> + pte = pte_start + i; >>> + if (pte_val(*pte)) >>> + break; >>> + } >>> + >>> + /* free a pte talbe */ >>> + if (i == PTRS_PER_PTE) { >>> + free_pagetable(pmd_page(*pmd)); >> >> The memory may be allocated at booting. So it is very dangerous to >> free it without any check. > The page is only used by page table, so is safe to free it when all the page table > entries have been cleared, right? Yes, but I guess we need to do more. For example, all boot memory are in memblock.reserved, and you don't update memblock here. Thanks Wen Congyang > >> >>> + pmd_clear(pmd); >>> + } >>> +} >>> + >>> +static void free_pmd_table(pmd_t *pmd_start, pud_t *pud) >>> +{ >>> + pmd_t *pmd; >>> + int i; >>> + >>> + for (i = 0; i < PTRS_PER_PMD; i++) { >>> + pmd = pmd_start + i; >>> + if (pmd_val(*pmd)) >>> + break; >>> + } >>> + >>> + /* free a pmd talbe */ >>> + if (i == PTRS_PER_PMD) { >>> + free_pagetable(pud_page(*pud)); >>> + pud_clear(pud); >>> + } >>> +} >>> + >>> +static void free_pud_table(pud_t *pud_start, pgd_t *pgd) >>> +{ >>> + pud_t *pud; >>> + int i; >>> + >>> + for (i = 0; i < PTRS_PER_PUD; i++) { >>> + pud = pud_start + i; >>> + if (pud_val(*pud)) >>> + break; >>> + } >>> + >>> + /* free a pud table */ >>> + if (i == PTRS_PER_PUD) { >>> + free_pagetable(pgd_page(*pgd)); >>> + pgd_clear(pgd); >>> + } >>> +} >>> + >>> static void __meminit >>> phys_pte_remove(pte_t *pte_page, unsigned long addr, unsigned long end) >>> { >>> @@ -704,21 +772,19 @@ phys_pmd_remove(pmd_t *pmd_page, unsigned long addr, unsigned long end) >>> unsigned long pages = 0, next; >>> int i = pmd_index(addr); >>> >>> - for (; i < PTRS_PER_PMD; i++, addr = next) { >>> + for (; i < PTRS_PER_PMD && addr < end; i++, addr = next) { >>> unsigned long pte_phys; >>> pmd_t *pmd = pmd_page + pmd_index(addr); >>> pte_t *pte; >>> >>> - if (addr >= end) >>> - break; >>> - >>> - next = (addr & PMD_MASK) + PMD_SIZE; >>> + next = pmd_addr_end(addr, end); >>> >>> if (!pmd_present(*pmd)) >>> continue; >>> >>> if (pmd_large(*pmd)) { >>> - if ((addr & ~PMD_MASK) == 0 && next <= end) { >>> + if (IS_ALIGNED(addr, PMD_SIZE) && >>> + IS_ALIGNED(next, PMD_SIZE)) { >>> set_pmd(pmd, __pmd(0)); >>> pages++; >>> continue; >>> @@ -729,7 +795,8 @@ phys_pmd_remove(pmd_t *pmd_page, unsigned long addr, unsigned long end) >>> * so split 2M page to 4K page. >>> */ >>> pte = alloc_low_page(&pte_phys); >>> - __split_large_page((pte_t *)pmd, addr, pte); >>> + __split_large_page((pte_t *)pmd, >>> + (unsigned long)__va(addr), pte); >>> >>> spin_lock(&init_mm.page_table_lock); >>> pmd_populate_kernel(&init_mm, pmd, __va(pte_phys)); >>> @@ -738,7 +805,8 @@ phys_pmd_remove(pmd_t *pmd_page, unsigned long addr, unsigned long end) >>> >>> spin_lock(&init_mm.page_table_lock); >>> pte = map_low_page((pte_t *)pmd_page_vaddr(*pmd)); >>> - phys_pte_remove(pte, addr, end); >>> + phys_pte_remove(pte, addr, next); >>> + free_pte_table(pte, pmd); >>> unmap_low_page(pte); >>> spin_unlock(&init_mm.page_table_lock); >>> } >>> @@ -751,21 +819,19 @@ phys_pud_remove(pud_t *pud_page, unsigned long addr, unsigned long end) >>> unsigned long pages = 0, next; >>> int i = pud_index(addr); >>> >>> - for (; i < PTRS_PER_PUD; i++, addr = next) { >>> + for (; i < PTRS_PER_PUD && addr < end; i++, addr = next) { >>> unsigned long pmd_phys; >>> pud_t *pud = pud_page + pud_index(addr); >>> pmd_t *pmd; >>> >>> - if (addr >= end) >>> - break; >>> - >>> - next = (addr & PUD_MASK) + PUD_SIZE; >>> + next = pud_addr_end(addr, end); >>> >>> if (!pud_present(*pud)) >>> continue; >>> >>> if (pud_large(*pud)) { >>> - if ((addr & ~PUD_MASK) == 0 && next <= end) { >>> + if (IS_ALIGNED(addr, PUD_SIZE) && >>> + IS_ALIGNED(next, PUD_SIZE)) { >>> set_pud(pud, __pud(0)); >>> pages++; >>> continue; >>> @@ -776,15 +842,18 @@ phys_pud_remove(pud_t *pud_page, unsigned long addr, unsigned long end) >>> * so split 1G page to 2M page. >>> */ >>> pmd = alloc_low_page(&pmd_phys); >>> - __split_large_page((pte_t *)pud, addr, (pte_t *)pmd); >>> + __split_large_page((pte_t *)pud, >>> + (unsigned long)__va(addr), >>> + (pte_t *)pmd); >>> >>> spin_lock(&init_mm.page_table_lock); >>> pud_populate(&init_mm, pud, __va(pmd_phys)); >>> spin_unlock(&init_mm.page_table_lock); >>> } >>> >>> - pmd = map_low_page(pmd_offset(pud, 0)); >>> - phys_pmd_remove(pmd, addr, end); >>> + pmd = map_low_page((pmd_t *)pud_page_vaddr(*pud)); >> >> Hmm, pmd_offset(pud, 0) is equal to (pmd_t *)pud_page_vaddr(*pud). >> >> Is it OK to merge your patch into my patch? >> > Yes, sure. > > Thanks, > Jianguo Wu > >> Thanks >> Wen Congyang >> >>> + phys_pmd_remove(pmd, addr, next); >>> + free_pmd_table(pmd, pud); >>> unmap_low_page(pmd); >>> __flush_tlb_all(); >>> } >>> @@ -805,15 +874,14 @@ kernel_physical_mapping_remove(unsigned long start, unsigned long end) >>> pgd_t *pgd = pgd_offset_k(start); >>> pud_t *pud; >>> >>> - next = (start + PGDIR_SIZE) & PGDIR_MASK; >>> - if (next > end) >>> - next = end; >>> + next = pgd_addr_end(start, end); >>> >>> if (!pgd_present(*pgd)) >>> continue; >>> >>> pud = map_low_page((pud_t *)pgd_page_vaddr(*pgd)); >>> - phys_pud_remove(pud, __pa(start), __pa(end)); >>> + phys_pud_remove(pud, __pa(start), __pa(next)); >>> + free_pud_table(pud, pgd); >>> unmap_low_page(pud); >>> } >>> >>> -- 1.7.6.1 . >>> >>> >>> On 2012-10-5 10:36, Yasuaki Ishimatsu wrote: >>>> From: Wen Congyang <wency@cn.fujitsu.com> >>>> >>>> For hot removing memory, we sholud remove page table about the memory. >>>> So the patch searches a page table about the removed memory, and clear >>>> page table. >>>> >>>> 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: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> >>>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> >>>> --- >>>> arch/x86/include/asm/pgtable_types.h | 1 >>>> arch/x86/mm/init_64.c | 147 +++++++++++++++++++++++++++++++++++ >>>> arch/x86/mm/pageattr.c | 47 +++++------ >>>> 3 files changed, 173 insertions(+), 22 deletions(-) >>>> >>>> Index: linux-3.6/arch/x86/mm/init_64.c >>>> =================================================================== >>>> --- linux-3.6.orig/arch/x86/mm/init_64.c 2012-10-04 18:30:21.171698416 +0900 >>>> +++ linux-3.6/arch/x86/mm/init_64.c 2012-10-04 18:30:27.317704652 +0900 >>>> @@ -675,6 +675,151 @@ int arch_add_memory(int nid, u64 start, >>>> } >>>> EXPORT_SYMBOL_GPL(arch_add_memory); >>>> >>>> +static void __meminit >>>> +phys_pte_remove(pte_t *pte_page, unsigned long addr, unsigned long end) >>>> +{ >>>> + unsigned pages = 0; >>>> + int i = pte_index(addr); >>>> + >>>> + pte_t *pte = pte_page + pte_index(addr); >>>> + >>>> + for (; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) { >>>> + >>>> + if (addr >= end) >>>> + break; >>>> + >>>> + if (!pte_present(*pte)) >>>> + continue; >>>> + >>>> + pages++; >>>> + set_pte(pte, __pte(0)); >>>> + } >>>> + >>>> + update_page_count(PG_LEVEL_4K, -pages); >>>> +} >>>> + >>>> +static void __meminit >>>> +phys_pmd_remove(pmd_t *pmd_page, unsigned long addr, unsigned long end) >>>> +{ >>>> + unsigned long pages = 0, next; >>>> + int i = pmd_index(addr); >>>> + >>>> + for (; i < PTRS_PER_PMD; i++, addr = next) { >>>> + unsigned long pte_phys; >>>> + pmd_t *pmd = pmd_page + pmd_index(addr); >>>> + pte_t *pte; >>>> + >>>> + if (addr >= end) >>>> + break; >>>> + >>>> + next = (addr & PMD_MASK) + PMD_SIZE; >>>> + >>>> + if (!pmd_present(*pmd)) >>>> + continue; >>>> + >>>> + if (pmd_large(*pmd)) { >>>> + if ((addr & ~PMD_MASK) == 0 && next <= end) { >>>> + set_pmd(pmd, __pmd(0)); >>>> + pages++; >>>> + continue; >>>> + } >>>> + >>>> + /* >>>> + * We use 2M page, but we need to remove part of them, >>>> + * so split 2M page to 4K page. >>>> + */ >>>> + pte = alloc_low_page(&pte_phys); >>>> + __split_large_page((pte_t *)pmd, addr, pte); >>>> + >>>> + spin_lock(&init_mm.page_table_lock); >>>> + pmd_populate_kernel(&init_mm, pmd, __va(pte_phys)); >>>> + spin_unlock(&init_mm.page_table_lock); >>>> + } >>>> + >>>> + spin_lock(&init_mm.page_table_lock); >>>> + pte = map_low_page((pte_t *)pmd_page_vaddr(*pmd)); >>>> + phys_pte_remove(pte, addr, end); >>>> + unmap_low_page(pte); >>>> + spin_unlock(&init_mm.page_table_lock); >>>> + } >>>> + update_page_count(PG_LEVEL_2M, -pages); >>>> +} >>>> + >>>> +static void __meminit >>>> +phys_pud_remove(pud_t *pud_page, unsigned long addr, unsigned long end) >>>> +{ >>>> + unsigned long pages = 0, next; >>>> + int i = pud_index(addr); >>>> + >>>> + for (; i < PTRS_PER_PUD; i++, addr = next) { >>>> + unsigned long pmd_phys; >>>> + pud_t *pud = pud_page + pud_index(addr); >>>> + pmd_t *pmd; >>>> + >>>> + if (addr >= end) >>>> + break; >>>> + >>>> + next = (addr & PUD_MASK) + PUD_SIZE; >>>> + >>>> + if (!pud_present(*pud)) >>>> + continue; >>>> + >>>> + if (pud_large(*pud)) { >>>> + if ((addr & ~PUD_MASK) == 0 && next <= end) { >>>> + set_pud(pud, __pud(0)); >>>> + pages++; >>>> + continue; >>>> + } >>>> + >>>> + /* >>>> + * We use 1G page, but we need to remove part of them, >>>> + * so split 1G page to 2M page. >>>> + */ >>>> + pmd = alloc_low_page(&pmd_phys); >>>> + __split_large_page((pte_t *)pud, addr, (pte_t *)pmd); >>>> + >>>> + spin_lock(&init_mm.page_table_lock); >>>> + pud_populate(&init_mm, pud, __va(pmd_phys)); >>>> + spin_unlock(&init_mm.page_table_lock); >>>> + } >>>> + >>>> + pmd = map_low_page(pmd_offset(pud, 0)); >>>> + phys_pmd_remove(pmd, addr, end); >>>> + unmap_low_page(pmd); >>>> + __flush_tlb_all(); >>>> + } >>>> + __flush_tlb_all(); >>>> + >>>> + update_page_count(PG_LEVEL_1G, -pages); >>>> +} >>>> + >>>> +void __meminit >>>> +kernel_physical_mapping_remove(unsigned long start, unsigned long end) >>>> +{ >>>> + unsigned long next; >>>> + >>>> + start = (unsigned long)__va(start); >>>> + end = (unsigned long)__va(end); >>>> + >>>> + for (; start < end; start = next) { >>>> + pgd_t *pgd = pgd_offset_k(start); >>>> + pud_t *pud; >>>> + >>>> + next = (start + PGDIR_SIZE) & PGDIR_MASK; >>>> + if (next > end) >>>> + next = end; >>>> + >>>> + if (!pgd_present(*pgd)) >>>> + continue; >>>> + >>>> + pud = map_low_page((pud_t *)pgd_page_vaddr(*pgd)); >>>> + phys_pud_remove(pud, __pa(start), __pa(end)); >>>> + unmap_low_page(pud); >>>> + } >>>> + >>>> + __flush_tlb_all(); >>>> +} >>>> + >>>> #ifdef CONFIG_MEMORY_HOTREMOVE >>>> int __ref arch_remove_memory(u64 start, u64 size) >>>> { >>>> @@ -687,6 +832,8 @@ int __ref arch_remove_memory(u64 start, >>>> ret = __remove_pages(zone, start_pfn, nr_pages); >>>> WARN_ON_ONCE(ret); >>>> >>>> + kernel_physical_mapping_remove(start, start + size); >>>> + >>>> return ret; >>>> } >>>> #endif >>>> Index: linux-3.6/arch/x86/include/asm/pgtable_types.h >>>> =================================================================== >>>> --- linux-3.6.orig/arch/x86/include/asm/pgtable_types.h 2012-10-04 18:26:51.925486954 +0900 >>>> +++ linux-3.6/arch/x86/include/asm/pgtable_types.h 2012-10-04 18:30:27.322704656 +0900 >>>> @@ -334,6 +334,7 @@ static inline void update_page_count(int >>>> * as a pte too. >>>> */ >>>> extern pte_t *lookup_address(unsigned long address, unsigned int *level); >>>> +extern int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase); >>>> >>>> #endif /* !__ASSEMBLY__ */ >>>> >>>> Index: linux-3.6/arch/x86/mm/pageattr.c >>>> =================================================================== >>>> --- linux-3.6.orig/arch/x86/mm/pageattr.c 2012-10-04 18:26:51.923486952 +0900 >>>> +++ linux-3.6/arch/x86/mm/pageattr.c 2012-10-04 18:30:27.328704662 +0900 >>>> @@ -501,21 +501,13 @@ out_unlock: >>>> return do_split; >>>> } >>>> >>>> -static int split_large_page(pte_t *kpte, unsigned long address) >>>> +int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase) >>>> { >>>> unsigned long pfn, pfninc = 1; >>>> unsigned int i, level; >>>> - pte_t *pbase, *tmp; >>>> + pte_t *tmp; >>>> pgprot_t ref_prot; >>>> - struct page *base; >>>> - >>>> - if (!debug_pagealloc) >>>> - spin_unlock(&cpa_lock); >>>> - base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0); >>>> - if (!debug_pagealloc) >>>> - spin_lock(&cpa_lock); >>>> - if (!base) >>>> - return -ENOMEM; >>>> + struct page *base = virt_to_page(pbase); >>>> >>>> spin_lock(&pgd_lock); >>>> /* >>>> @@ -523,10 +515,11 @@ static int split_large_page(pte_t *kpte, >>>> * up for us already: >>>> */ >>>> tmp = lookup_address(address, &level); >>>> - if (tmp != kpte) >>>> - goto out_unlock; >>>> + if (tmp != kpte) { >>>> + spin_unlock(&pgd_lock); >>>> + return 1; >>>> + } >>>> >>>> - pbase = (pte_t *)page_address(base); >>>> paravirt_alloc_pte(&init_mm, page_to_pfn(base)); >>>> ref_prot = pte_pgprot(pte_clrhuge(*kpte)); >>>> /* >>>> @@ -579,17 +572,27 @@ static int split_large_page(pte_t *kpte, >>>> * going on. >>>> */ >>>> __flush_tlb_all(); >>>> + spin_unlock(&pgd_lock); >>>> >>>> - base = NULL; >>>> + return 0; >>>> +} >>>> >>>> -out_unlock: >>>> - /* >>>> - * If we dropped out via the lookup_address check under >>>> - * pgd_lock then stick the page back into the pool: >>>> - */ >>>> - if (base) >>>> +static int split_large_page(pte_t *kpte, unsigned long address) >>>> +{ >>>> + pte_t *pbase; >>>> + struct page *base; >>>> + >>>> + if (!debug_pagealloc) >>>> + spin_unlock(&cpa_lock); >>>> + base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0); >>>> + if (!debug_pagealloc) >>>> + spin_lock(&cpa_lock); >>>> + if (!base) >>>> + return -ENOMEM; >>>> + >>>> + pbase = (pte_t *)page_address(base); >>>> + if (__split_large_page(kpte, address, pbase)) >>>> __free_page(base); >>>> - spin_unlock(&pgd_lock); >>>> >>>> return 0; >>>> } >>>> >>>> -- >>>> To unsubscribe, send a message with 'unsubscribe linux-mm' in >>>> the body to majordomo@kvack.org. For more info on Linux MM, >>>> see: http://www.linux-mm.org/ . >>>> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> >>>> >>> >>> >> >> > > -- To unsubscribe from this list: send the line "unsubscribe sparclinux" 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/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 5596dfa..81f9c3b 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -675,6 +675,74 @@ int arch_add_memory(int nid, u64 start, u64 size) } EXPORT_SYMBOL_GPL(arch_add_memory); +static inline void free_pagetable(struct page *page) +{ + struct zone *zone; + + __ClearPageReserved(page); + __free_page(page); + + zone = page_zone(page); + zone_span_writelock(zone); + zone->present_pages++; + zone_span_writeunlock(zone); + totalram_pages++; +} + +static void free_pte_table(pte_t *pte_start, pmd_t *pmd) +{ + pte_t *pte; + int i; + + for (i = 0; i < PTRS_PER_PTE; i++) { + pte = pte_start + i; + if (pte_val(*pte)) + break; + } + + /* free a pte talbe */ + if (i == PTRS_PER_PTE) { + free_pagetable(pmd_page(*pmd)); + pmd_clear(pmd); + } +} + +static void free_pmd_table(pmd_t *pmd_start, pud_t *pud) +{ + pmd_t *pmd; + int i; + + for (i = 0; i < PTRS_PER_PMD; i++) { + pmd = pmd_start + i; + if (pmd_val(*pmd)) + break; + } + + /* free a pmd talbe */ + if (i == PTRS_PER_PMD) { + free_pagetable(pud_page(*pud)); + pud_clear(pud); + } +} + +static void free_pud_table(pud_t *pud_start, pgd_t *pgd) +{ + pud_t *pud; + int i; + + for (i = 0; i < PTRS_PER_PUD; i++) { + pud = pud_start + i; + if (pud_val(*pud)) + break; + } + + /* free a pud table */ + if (i == PTRS_PER_PUD) { + free_pagetable(pgd_page(*pgd)); + pgd_clear(pgd); + } +} + static void __meminit phys_pte_remove(pte_t *pte_page, unsigned long addr, unsigned long end) { @@ -704,21 +772,19 @@ phys_pmd_remove(pmd_t *pmd_page, unsigned long addr, unsigned long end) unsigned long pages = 0, next; int i = pmd_index(addr); - for (; i < PTRS_PER_PMD; i++, addr = next) { + for (; i < PTRS_PER_PMD && addr < end; i++, addr = next) { unsigned long pte_phys; pmd_t *pmd = pmd_page + pmd_index(addr); pte_t *pte; - if (addr >= end) - break; - - next = (addr & PMD_MASK) + PMD_SIZE; + next = pmd_addr_end(addr, end); if (!pmd_present(*pmd)) continue; if (pmd_large(*pmd)) { - if ((addr & ~PMD_MASK) == 0 && next <= end) { + if (IS_ALIGNED(addr, PMD_SIZE) && + IS_ALIGNED(next, PMD_SIZE)) { set_pmd(pmd, __pmd(0)); pages++; continue; @@ -729,7 +795,8 @@ phys_pmd_remove(pmd_t *pmd_page, unsigned long addr, unsigned long end) * so split 2M page to 4K page. */ pte = alloc_low_page(&pte_phys); - __split_large_page((pte_t *)pmd, addr, pte); + __split_large_page((pte_t *)pmd, + (unsigned long)__va(addr), pte); spin_lock(&init_mm.page_table_lock); pmd_populate_kernel(&init_mm, pmd, __va(pte_phys)); @@ -738,7 +805,8 @@ phys_pmd_remove(pmd_t *pmd_page, unsigned long addr, unsigned long end) spin_lock(&init_mm.page_table_lock); pte = map_low_page((pte_t *)pmd_page_vaddr(*pmd)); - phys_pte_remove(pte, addr, end); + phys_pte_remove(pte, addr, next); + free_pte_table(pte, pmd); unmap_low_page(pte); spin_unlock(&init_mm.page_table_lock); } @@ -751,21 +819,19 @@ phys_pud_remove(pud_t *pud_page, unsigned long addr, unsigned long end) unsigned long pages = 0, next; int i = pud_index(addr); - for (; i < PTRS_PER_PUD; i++, addr = next) { + for (; i < PTRS_PER_PUD && addr < end; i++, addr = next) { unsigned long pmd_phys; pud_t *pud = pud_page + pud_index(addr); pmd_t *pmd; - if (addr >= end) - break; - - next = (addr & PUD_MASK) + PUD_SIZE; + next = pud_addr_end(addr, end); if (!pud_present(*pud)) continue; if (pud_large(*pud)) { - if ((addr & ~PUD_MASK) == 0 && next <= end) { + if (IS_ALIGNED(addr, PUD_SIZE) && + IS_ALIGNED(next, PUD_SIZE)) { set_pud(pud, __pud(0)); pages++; continue; @@ -776,15 +842,18 @@ phys_pud_remove(pud_t *pud_page, unsigned long addr, unsigned long end) * so split 1G page to 2M page. */ pmd = alloc_low_page(&pmd_phys); - __split_large_page((pte_t *)pud, addr, (pte_t *)pmd); + __split_large_page((pte_t *)pud, + (unsigned long)__va(addr), + (pte_t *)pmd); spin_lock(&init_mm.page_table_lock); pud_populate(&init_mm, pud, __va(pmd_phys)); spin_unlock(&init_mm.page_table_lock); } - pmd = map_low_page(pmd_offset(pud, 0)); - phys_pmd_remove(pmd, addr, end); + pmd = map_low_page((pmd_t *)pud_page_vaddr(*pud)); + phys_pmd_remove(pmd, addr, next); + free_pmd_table(pmd, pud); unmap_low_page(pmd); __flush_tlb_all(); } @@ -805,15 +874,14 @@ kernel_physical_mapping_remove(unsigned long start, unsigned long end) pgd_t *pgd = pgd_offset_k(start); pud_t *pud; - next = (start + PGDIR_SIZE) & PGDIR_MASK; - if (next > end) - next = end; + next = pgd_addr_end(start, end); if (!pgd_present(*pgd)) continue; pud = map_low_page((pud_t *)pgd_page_vaddr(*pgd)); - phys_pud_remove(pud, __pa(start), __pa(end)); + phys_pud_remove(pud, __pa(start), __pa(next)); + free_pud_table(pud, pgd); unmap_low_page(pud); }