Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753574Ab2HAGBi (ORCPT ); Wed, 1 Aug 2012 02:01:38 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:45114 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753384Ab2HAGBf (ORCPT ); Wed, 1 Aug 2012 02:01:35 -0400 X-IronPort-AV: E=Sophos;i="4.77,691,1336320000"; d="scan'208";a="5526140" Message-ID: <5018C76D.8000205@cn.fujitsu.com> Date: Wed, 01 Aug 2012 14:06:37 +0800 From: Wen Congyang User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100413 Fedora/3.0.4-2.fc13 Thunderbird/3.0.4 MIME-Version: 1.0 To: jencce zhou CC: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, linux-ia64@vger.kernel.org, cmetcalf@tilera.com, rientjes@google.com, liuj97@gmail.com, len.brown@intel.com, benh@kernel.crashing.org, paulus@samba.org, cl@linux.com, minchan.kim@gmail.com, akpm@linux-foundation.org, kosaki.motohiro@jp.fujitsu.com, Yasuaki ISIMATU Subject: Re: [RFC PATCH v5 12/19] memory-hotplug: introduce new function arch_remove_memory() References: <50126B83.3050201@cn.fujitsu.com> <50126E2F.8010301@cn.fujitsu.com> In-Reply-To: X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/08/01 14:02:04, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/08/01 14:02:05, Serialize complete at 2012/08/01 14:02:05 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 16529 Lines: 489 At 08/01/2012 10:44 AM, jencce zhou Wrote: > 2012/7/27 Wen Congyang : >> We don't call __add_pages() directly in the function add_memory() >> because some other architecture related things need to be done >> before or after calling __add_pages(). So we should introduce >> a new function arch_remove_memory() to revert the things >> done in arch_add_memory(). >> >> Note: the function for s390 is not implemented(I don't know how to >> implement it for s390). >> >> CC: David Rientjes >> CC: Jiang Liu >> CC: Len Brown >> CC: Benjamin Herrenschmidt >> CC: Paul Mackerras >> CC: Christoph Lameter >> Cc: Minchan Kim >> CC: Andrew Morton >> CC: KOSAKI Motohiro >> CC: Yasuaki Ishimatsu >> Signed-off-by: Wen Congyang >> --- >> arch/ia64/mm/init.c | 16 ++++ >> arch/powerpc/mm/mem.c | 14 +++ >> arch/s390/mm/init.c | 8 ++ >> arch/sh/mm/init.c | 15 +++ >> arch/tile/mm/init.c | 8 ++ >> arch/x86/include/asm/pgtable_types.h | 1 + >> arch/x86/mm/init_32.c | 10 ++ >> arch/x86/mm/init_64.c | 160 ++++++++++++++++++++++++++++++++++ >> arch/x86/mm/pageattr.c | 47 +++++----- >> include/linux/memory_hotplug.h | 1 + >> mm/memory_hotplug.c | 1 + >> 11 files changed, 259 insertions(+), 22 deletions(-) >> >> diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c >> index 0eab454..1e345ed 100644 >> --- a/arch/ia64/mm/init.c >> +++ b/arch/ia64/mm/init.c >> @@ -688,6 +688,22 @@ int arch_add_memory(int nid, u64 start, u64 size) >> >> return ret; >> } >> + >> +#ifdef CONFIG_MEMORY_HOTREMOVE >> +int arch_remove_memory(u64 start, u64 size) >> +{ >> + unsigned long start_pfn = start >> PAGE_SHIFT; >> + unsigned long nr_pages = size >> PAGE_SHIFT; >> + int ret; >> + >> + ret = __remove_pages(start_pfn, nr_pages); >> + if (ret) >> + pr_warn("%s: Problem encountered in __remove_pages() as" >> + " ret=%d\n", __func__, ret); >> + >> + return ret; >> +} >> +#endif >> #endif >> > > in 3.5 ia64 implementation did not call __remove_pages at all. so why? This function only reverts the things done in arch_add_memory(), and it will be called when a memory device is removed. When adding a memory device, __add_pages() is called in arch_add_memory(), so call __remove_pages() in arch_remove_memory(). Thanks Wen Congyang > > >> /* >> diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c >> index baaafde..249cef4 100644 >> --- a/arch/powerpc/mm/mem.c >> +++ b/arch/powerpc/mm/mem.c >> @@ -133,6 +133,20 @@ int arch_add_memory(int nid, u64 start, u64 size) >> >> return __add_pages(nid, zone, start_pfn, nr_pages); >> } >> + >> +#ifdef CONFIG_MEMORY_HOTREMOVE >> +int arch_remove_memory(u64 start, u64 size) >> +{ >> + unsigned long start_pfn = start >> PAGE_SHIFT; >> + unsigned long nr_pages = size >> PAGE_SHIFT; >> + >> + start = (unsigned long)__va(start); >> + if (remove_section_mapping(start, start + size)) >> + return -EINVAL; >> + >> + return __remove_pages(start_pfn, nr_pages); >> +} >> +#endif >> #endif /* CONFIG_MEMORY_HOTPLUG */ >> >> /* >> diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c >> index 6adbc08..ca4bc46 100644 >> --- a/arch/s390/mm/init.c >> +++ b/arch/s390/mm/init.c >> @@ -257,4 +257,12 @@ int arch_add_memory(int nid, u64 start, u64 size) >> vmem_remove_mapping(start, size); >> return rc; >> } >> + >> +#ifdef CONFIG_MEMORY_HOTREMOVE >> +int arch_remove_memory(u64 start, u64 size) >> +{ >> + /* TODO */ >> + return -EBUSY; >> +} >> +#endif >> #endif /* CONFIG_MEMORY_HOTPLUG */ >> diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c >> index 82cc576..fc84491 100644 >> --- a/arch/sh/mm/init.c >> +++ b/arch/sh/mm/init.c >> @@ -558,4 +558,19 @@ int memory_add_physaddr_to_nid(u64 addr) >> EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid); >> #endif >> >> +#ifdef CONFIG_MEMORY_HOTREMOVE >> +int arch_remove_memory(u64 start, u64 size) >> +{ >> + unsigned long start_pfn = start >> PAGE_SHIFT; >> + unsigned long nr_pages = size >> PAGE_SHIFT; >> + int ret; >> + >> + ret = __remove_pages(start_pfn, nr_pages); >> + if (unlikely(ret)) >> + pr_warn("%s: Failed, __remove_pages() == %d\n", __func__, >> + ret); >> + >> + return ret; >> +} >> +#endif >> #endif /* CONFIG_MEMORY_HOTPLUG */ >> diff --git a/arch/tile/mm/init.c b/arch/tile/mm/init.c >> index ef29d6c..2749515 100644 >> --- a/arch/tile/mm/init.c >> +++ b/arch/tile/mm/init.c >> @@ -935,6 +935,14 @@ int remove_memory(u64 start, u64 size) >> { >> return -EINVAL; >> } >> + >> +#ifdef CONFIG_MEMORY_HOTREMOVE >> +int arch_remove_memory(u64 start, u64 size) >> +{ >> + /* TODO */ >> + return -EBUSY; >> +} >> +#endif >> #endif >> >> struct kmem_cache *pgd_cache; >> diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h >> index 013286a..b725af2 100644 >> --- a/arch/x86/include/asm/pgtable_types.h >> +++ b/arch/x86/include/asm/pgtable_types.h >> @@ -334,6 +334,7 @@ static inline void update_page_count(int level, unsigned long pages) { } >> * 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__ */ >> >> diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c >> index 575d86f..a690153 100644 >> --- a/arch/x86/mm/init_32.c >> +++ b/arch/x86/mm/init_32.c >> @@ -842,6 +842,16 @@ int arch_add_memory(int nid, u64 start, u64 size) >> >> return __add_pages(nid, zone, start_pfn, nr_pages); >> } >> + >> +#ifdef CONFIG_MEMORY_HOTREMOVE >> +int arch_remove_memory(unsigned long start, unsigned long size) >> +{ >> + unsigned long start_pfn = start >> PAGE_SHIFT; >> + unsigned long nr_pages = size >> PAGE_SHIFT; >> + >> + return __remove_pages(start_pfn, nr_pages); >> +} >> +#endif >> #endif >> >> /* >> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c >> index 2b6b4a3..f1554a9 100644 >> --- a/arch/x86/mm/init_64.c >> +++ b/arch/x86/mm/init_64.c >> @@ -675,6 +675,166 @@ int arch_add_memory(int nid, u64 start, u64 size) >> } >> 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(unsigned long start, unsigned long size) >> +{ >> + unsigned long start_pfn = start >> PAGE_SHIFT; >> + unsigned long nr_pages = size >> PAGE_SHIFT; >> + int ret; >> + >> + ret = __remove_pages(start_pfn, nr_pages); >> + WARN_ON_ONCE(ret); >> + >> + kernel_physical_mapping_remove(start, start + size); >> + >> + return ret; >> +} >> +#endif >> #endif /* CONFIG_MEMORY_HOTPLUG */ >> >> static struct kcore_list kcore_vsyscall; >> diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c >> index 931930a..c22963d 100644 >> --- a/arch/x86/mm/pageattr.c >> +++ b/arch/x86/mm/pageattr.c >> @@ -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, unsigned long address) >> * 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, unsigned long address) >> * 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; >> } >> diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h >> index 8bf820d..0d500be 100644 >> --- a/include/linux/memory_hotplug.h >> +++ b/include/linux/memory_hotplug.h >> @@ -85,6 +85,7 @@ extern void __online_page_free(struct page *page); >> >> #ifdef CONFIG_MEMORY_HOTREMOVE >> extern bool is_pageblock_removable_nolock(struct page *page); >> +extern int arch_remove_memory(unsigned long start, unsigned long size); >> #endif /* CONFIG_MEMORY_HOTREMOVE */ >> >> /* reasonably generic interface to expand the physical pages in a zone */ >> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c >> index a9e1579..0c932e1 100644 >> --- a/mm/memory_hotplug.c >> +++ b/mm/memory_hotplug.c >> @@ -1071,6 +1071,7 @@ int __ref remove_memory(int nid, u64 start, u64 size) > > line 1071? which version does this patch base on? thanks a lot. > > >> /* remove memmap entry */ >> firmware_map_remove(start, start + size, "System RAM"); >> >> + arch_remove_memory(start, size); >> out: >> unlock_memory_hotplug(); >> return ret; >> -- >> 1.7.1 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/