Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755577Ab2F3P61 (ORCPT ); Sat, 30 Jun 2012 11:58:27 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:39109 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754103Ab2F3P6Z (ORCPT ); Sat, 30 Jun 2012 11:58:25 -0400 Message-ID: <4FEF2214.4000205@gmail.com> Date: Sat, 30 Jun 2012 23:58:12 +0800 From: Jiang Liu User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20120615 Thunderbird/13.0.1 MIME-Version: 1.0 To: Yasuaki Ishimatsu CC: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, 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, wency@cn.fujitsu.com Subject: Re: [RFC PATCH 10/12] memory-hotplug : free memmap of sparse-vmemmap References: <4FEA9C88.1070800@jp.fujitsu.com> <4FEAA09F.5000907@jp.fujitsu.com> In-Reply-To: <4FEAA09F.5000907@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6616 Lines: 196 On 06/27/2012 01:56 PM, Yasuaki Ishimatsu wrote: > I don't think that all pages of virtual mapping in removed memory can be > freed, since page which type is MIX_SECTION_INFO is difficult to free. > So, the patch only frees page which type is SECTION_INFO at first. > > CC: Len Brown > CC: Benjamin Herrenschmidt > CC: Paul Mackerras > CC: Christoph Lameter > Cc: Minchan Kim > CC: Andrew Morton > CC: KOSAKI Motohiro > CC: Wen Congyang > Signed-off-by: Yasuaki Ishimatsu > > --- > arch/x86/mm/init_64.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/mm.h | 2 + > mm/memory_hotplug.c | 5 ++ > mm/sparse.c | 5 +- > 4 files changed, 99 insertions(+), 2 deletions(-) > > Index: linux-3.5-rc4/include/linux/mm.h > =================================================================== > --- linux-3.5-rc4.orig/include/linux/mm.h 2012-06-27 09:11:13.790150442 +0900 > +++ linux-3.5-rc4/include/linux/mm.h 2012-06-27 09:11:16.433117400 +0900 > @@ -1588,6 +1588,8 @@ int vmemmap_populate(struct page *start_ > 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, > Index: linux-3.5-rc4/mm/sparse.c > =================================================================== > --- linux-3.5-rc4.orig/mm/sparse.c 2012-06-27 09:06:35.317631878 +0900 > +++ linux-3.5-rc4/mm/sparse.c 2012-06-27 09:11:16.434117388 +0900 > @@ -614,12 +614,13 @@ static inline struct page *kmalloc_secti > /* 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) > Index: linux-3.5-rc4/arch/x86/mm/init_64.c > =================================================================== > --- linux-3.5-rc4.orig/arch/x86/mm/init_64.c 2012-06-27 09:11:13.791150430 +0900 > +++ linux-3.5-rc4/arch/x86/mm/init_64.c 2012-06-27 09:11:59.254581998 +0900 > @@ -978,6 +978,95 @@ vmemmap_populate(struct page *start_page > return 0; > } > > +unsigned long find_and_clear_pte_page(unsigned long addr, unsigned long end, > + struct page *page) I think the third parameter should be "struct page **pp" instead of "struct page *page". And "page = pte_page(*pte)" should be "*pp = pte_page(*pte)". Otherwise the found page pointer can't be returned to the caller and vmemmap_kfree() just sees random value in variable "page". > +{ > + pgd_t *pgd; > + pud_t *pud; > + pmd_t *pmd; > + pte_t *pte; > + unsigned long next; > + > + page = NULL; > + > + pgd = pgd_offset_k(addr); > + if (pgd_none(*pgd)) > + return PAGE_SIZE; > + > + pud = pud_offset(pgd, addr); > + if (pud_none(*pud)) > + return PAGE_SIZE; > + > + 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 = pte_page(*pte); > + pte_clear(&init_mm, addr, pte); > + } else { > + next = pmd_addr_end(addr, end); > + > + pmd = pmd_offset(pud, addr); > + if (pmd_none(*pmd)) > + return next; > + > + page = pmd_page(*pmd); > + pmd_clear(pmd); > + } > + > + return next; > +} > + > +void __meminit > +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; > + unsigned int order; > + struct page *page; > + > + for (; addr < end; addr = next) { > + next = find_and_clear_pte_page(addr, end, page); > + if (!page) > + continue; > + > + if (is_vmalloc_addr(page)) > + vfree(page); > + else { > + order = next - addr; > + free_pages((unsigned long)page, > + get_order(sizeof(struct page) * order)); > + } > + } > +} > + > +void __meminit > +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; > + unsigned long magic; > + > + for (; addr < end; addr = next) { > + next = find_and_clear_pte_page(addr, end, page); > + if (!page) > + continue; > + > + magic = (unsigned long) page->lru.next; > + if (magic == SECTION_INFO) > + put_page_bootmem(page); > + } > +} > + > void __meminit > register_page_bootmem_memmap(unsigned long section_nr, struct page *start_page, > unsigned long size) > Index: linux-3.5-rc4/mm/memory_hotplug.c > =================================================================== > --- linux-3.5-rc4.orig/mm/memory_hotplug.c 2012-06-27 09:11:13.789150454 +0900 > +++ linux-3.5-rc4/mm/memory_hotplug.c 2012-06-27 09:11:16.436117363 +0900 > @@ -303,6 +303,8 @@ static int __meminit __add_section(int n > #ifdef CONFIG_SPARSEMEM_VMEMMAP > static int __remove_section(struct zone *zone, struct mem_section *ms) > { > + unsigned long flags; > + struct pglist_data *pgdat = zone->zone_pgdat; > int ret; > > if (!valid_section(ms)) > @@ -310,6 +312,9 @@ static int __remove_section(struct zone > > ret = unregister_memory_section(ms); > > + pgdat_resize_lock(pgdat, &flags); > + sparse_remove_one_section(zone, ms); > + pgdat_resize_unlock(pgdat, &flags); > return ret; > } > #else > > -- > 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 > -- 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/