Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161706Ab3DEL7Q (ORCPT ); Fri, 5 Apr 2013 07:59:16 -0400 Received: from mga02.intel.com ([134.134.136.20]:14075 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161622Ab3DEL63 (ORCPT ); Fri, 5 Apr 2013 07:58:29 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.87,414,1363158000"; d="scan'208";a="312816035" From: "Kirill A. Shutemov" To: Andrea Arcangeli , Andrew Morton Cc: Al Viro , Hugh Dickins , Wu Fengguang , Jan Kara , Mel Gorman , linux-mm@kvack.org, Andi Kleen , Matthew Wilcox , "Kirill A. Shutemov" , Hillf Danton , Dave Hansen , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCHv3, RFC 20/34] thp: handle file pages in split_huge_page() Date: Fri, 5 Apr 2013 14:59:44 +0300 Message-Id: <1365163198-29726-21-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1365163198-29726-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1365163198-29726-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4635 Lines: 150 From: "Kirill A. Shutemov" The base scheme is the same as for anonymous pages, but we walk by mapping->i_mmap rather then anon_vma->rb_root. __split_huge_page_refcount() has been tunned a bit: we need to transfer PG_swapbacked to tail pages. Splitting mapped pages haven't tested at all, since we cannot mmap() file-backed huge pages yet. Signed-off-by: Kirill A. Shutemov --- mm/huge_memory.c | 71 +++++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 59 insertions(+), 12 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 46a44ac..ac0dc80 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1637,24 +1637,25 @@ static void __split_huge_page_refcount(struct page *page) */ page_tail->_mapcount = page->_mapcount; - BUG_ON(page_tail->mapping); page_tail->mapping = page->mapping; - page_tail->index = page->index + i; page_nid_xchg_last(page_tail, page_nid_last(page)); - BUG_ON(!PageAnon(page_tail)); BUG_ON(!PageUptodate(page_tail)); BUG_ON(!PageDirty(page_tail)); - BUG_ON(!PageSwapBacked(page_tail)); lru_add_page_tail(page, page_tail, lruvec); } atomic_sub(tail_count, &page->_count); BUG_ON(atomic_read(&page->_count) <= 0); - __mod_zone_page_state(zone, NR_ANON_TRANSPARENT_HUGEPAGES, -1); - __mod_zone_page_state(zone, NR_ANON_PAGES, HPAGE_PMD_NR); + if (PageAnon(page)) { + __mod_zone_page_state(zone, NR_ANON_TRANSPARENT_HUGEPAGES, -1); + __mod_zone_page_state(zone, NR_ANON_PAGES, HPAGE_PMD_NR); + } else { + __mod_zone_page_state(zone, NR_FILE_TRANSPARENT_HUGEPAGES, -1); + __mod_zone_page_state(zone, NR_FILE_PAGES, HPAGE_PMD_NR); + } ClearPageCompound(page); compound_unlock(page); @@ -1754,7 +1755,7 @@ static int __split_huge_page_map(struct page *page, } /* must be called with anon_vma->root->rwsem held */ -static void __split_huge_page(struct page *page, +static void __split_anon_huge_page(struct page *page, struct anon_vma *anon_vma) { int mapcount, mapcount2; @@ -1801,14 +1802,11 @@ static void __split_huge_page(struct page *page, BUG_ON(mapcount != mapcount2); } -int split_huge_page(struct page *page) +static int split_anon_huge_page(struct page *page) { struct anon_vma *anon_vma; int ret = 1; - BUG_ON(is_huge_zero_pfn(page_to_pfn(page))); - BUG_ON(!PageAnon(page)); - /* * The caller does not necessarily hold an mmap_sem that would prevent * the anon_vma disappearing so we first we take a reference to it @@ -1826,7 +1824,7 @@ int split_huge_page(struct page *page) goto out_unlock; BUG_ON(!PageSwapBacked(page)); - __split_huge_page(page, anon_vma); + __split_anon_huge_page(page, anon_vma); count_vm_event(THP_SPLIT); BUG_ON(PageCompound(page)); @@ -1837,6 +1835,55 @@ out: return ret; } +static int split_file_huge_page(struct page *page) +{ + struct address_space *mapping = page->mapping; + pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); + struct vm_area_struct *vma; + int mapcount, mapcount2; + + BUG_ON(!PageHead(page)); + BUG_ON(PageTail(page)); + + mutex_lock(&mapping->i_mmap_mutex); + mapcount = 0; + vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) { + unsigned long addr = vma_address(page, vma); + mapcount += __split_huge_page_splitting(page, vma, addr); + } + + if (mapcount != page_mapcount(page)) + printk(KERN_ERR "mapcount %d page_mapcount %d\n", + mapcount, page_mapcount(page)); + BUG_ON(mapcount != page_mapcount(page)); + + __split_huge_page_refcount(page); + + mapcount2 = 0; + vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) { + unsigned long addr = vma_address(page, vma); + mapcount2 += __split_huge_page_map(page, vma, addr); + } + + if (mapcount != mapcount2) + printk(KERN_ERR "mapcount %d mapcount2 %d page_mapcount %d\n", + mapcount, mapcount2, page_mapcount(page)); + BUG_ON(mapcount != mapcount2); + count_vm_event(THP_SPLIT); + mutex_unlock(&mapping->i_mmap_mutex); + return 0; +} + +int split_huge_page(struct page *page) +{ + BUG_ON(is_huge_zero_pfn(page_to_pfn(page))); + + if (PageAnon(page)) + return split_anon_huge_page(page); + else + return split_file_huge_page(page); +} + #define VM_NO_THP (VM_SPECIAL|VM_MIXEDMAP|VM_HUGETLB|VM_SHARED|VM_MAYSHARE) int hugepage_madvise(struct vm_area_struct *vma, -- 1.7.10.4 -- 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/