Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934644Ab3CNRt3 (ORCPT ); Thu, 14 Mar 2013 13:49:29 -0400 Received: from mga14.intel.com ([143.182.124.37]:23908 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934549Ab3CNRtU (ORCPT ); Thu, 14 Mar 2013 13:49:20 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,845,1355126400"; d="scan'208";a="214771586" From: "Kirill A. Shutemov" To: Andrea Arcangeli , Andrew Morton , Al Viro , Hugh Dickins Cc: Wu Fengguang , Jan Kara , Mel Gorman , linux-mm@kvack.org, Andi Kleen , Matthew Wilcox , "Kirill A. Shutemov" , Hillf Danton , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCHv2, RFC 25/30] thp, mm: basic huge_fault implementation for generic_file_vm_ops Date: Thu, 14 Mar 2013 19:50:30 +0200 Message-Id: <1363283435-7666-26-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1363283435-7666-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1363283435-7666-1-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: 3135 Lines: 111 From: "Kirill A. Shutemov" It provide enough functionality for simple cases like ramfs. Need to be extended later. Signed-off-by: Kirill A. Shutemov --- mm/filemap.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) diff --git a/mm/filemap.c b/mm/filemap.c index 57611be..032fec39 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1781,6 +1781,80 @@ page_not_uptodate: } EXPORT_SYMBOL(filemap_fault); +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static int filemap_huge_fault(struct vm_area_struct *vma, struct vm_fault *vmf) +{ + struct file *file = vma->vm_file; + struct address_space *mapping = file->f_mapping; + struct inode *inode = mapping->host; + pgoff_t size, offset = vmf->pgoff; + unsigned long address = (unsigned long) vmf->virtual_address; + struct page *page; + int ret = 0; + + BUG_ON(((address >> PAGE_SHIFT) & HPAGE_CACHE_INDEX_MASK) != + (offset & HPAGE_CACHE_INDEX_MASK)); + +retry: + page = find_get_page(mapping, offset); + if (!page) { + gfp_t gfp_mask = mapping_gfp_mask(mapping) | __GFP_COLD; + page = alloc_pages(gfp_mask, HPAGE_PMD_ORDER); + if (!page) { + count_vm_event(THP_FAULT_FALLBACK); + return VM_FAULT_OOM; + } + count_vm_event(THP_FAULT_ALLOC); + ret = add_to_page_cache_lru(page, mapping, offset, GFP_KERNEL); + if (ret == 0) + ret = mapping->a_ops->readpage(file, page); + else if (ret == -EEXIST) + ret = 0; /* losing race to add is OK */ + page_cache_release(page); + if (!ret || ret == AOP_TRUNCATED_PAGE) + goto retry; + return ret; + } + + if (!lock_page_or_retry(page, vma->vm_mm, vmf->flags)) { + page_cache_release(page); + return ret | VM_FAULT_RETRY; + } + + /* Did it get truncated? */ + if (unlikely(page->mapping != mapping)) { + unlock_page(page); + put_page(page); + goto retry; + } + VM_BUG_ON(page->index != offset); + VM_BUG_ON(!PageUptodate(page)); + + if (!PageTransHuge(page)) { + unlock_page(page); + put_page(page); + /* Ask fallback to small pages */ + return VM_FAULT_OOM; + } + + /* + * Found the page and have a reference on it. + * We must recheck i_size under page lock. + */ + size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; + if (unlikely(offset >= size)) { + unlock_page(page); + page_cache_release(page); + return VM_FAULT_SIGBUS; + } + + vmf->page = page; + return ret | VM_FAULT_LOCKED; +} +#else +#define filemap_huge_fault NULL +#endif + int filemap_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) { struct page *page = vmf->page; @@ -1810,6 +1884,7 @@ EXPORT_SYMBOL(filemap_page_mkwrite); const struct vm_operations_struct generic_file_vm_ops = { .fault = filemap_fault, + .huge_fault = filemap_huge_fault, .page_mkwrite = filemap_page_mkwrite, .remap_pages = generic_file_remap_pages, }; -- 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/