Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934633Ab3CNR4M (ORCPT ); Thu, 14 Mar 2013 13:56:12 -0400 Received: from mga01.intel.com ([192.55.52.88]:1936 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934533Ab3CNRtS (ORCPT ); Thu, 14 Mar 2013 13:49:18 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,845,1355126400"; d="scan'208";a="302979131" 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 15/30] thp, libfs: initial support of thp in simple_read/write_begin/write_end Date: Thu, 14 Mar 2013 19:50:20 +0200 Message-Id: <1363283435-7666-16-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: 3077 Lines: 101 From: "Kirill A. Shutemov" For now we try to grab a huge cache page if gfp_mask has __GFP_COMP. It's probably to weak condition and need to be reworked later. Signed-off-by: Kirill A. Shutemov --- fs/libfs.c | 50 +++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 39 insertions(+), 11 deletions(-) diff --git a/fs/libfs.c b/fs/libfs.c index 916da8c..6edfa9d 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -383,7 +383,10 @@ EXPORT_SYMBOL(simple_setattr); int simple_readpage(struct file *file, struct page *page) { - clear_highpage(page); + if (PageTransHuge(page)) + zero_huge_user(page, 0, HPAGE_PMD_SIZE); + else + clear_highpage(page); flush_dcache_page(page); SetPageUptodate(page); unlock_page(page); @@ -394,21 +397,41 @@ int simple_write_begin(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, unsigned flags, struct page **pagep, void **fsdata) { - struct page *page; + struct page *page = NULL; pgoff_t index; index = pos >> PAGE_CACHE_SHIFT; - page = grab_cache_page_write_begin(mapping, index, flags); + /* XXX: too weak condition. Good enough for initial testing */ + if (mapping_can_have_hugepages(mapping)) { + page = grab_cache_huge_page_write_begin(mapping, + index & ~HPAGE_CACHE_INDEX_MASK, flags); + /* fallback to small page */ + if (!page || !PageTransHuge(page)) { + unsigned long offset; + offset = pos & ~PAGE_CACHE_MASK; + len = min_t(unsigned long, + len, PAGE_CACHE_SIZE - offset); + } + } + if (!page) + page = grab_cache_page_write_begin(mapping, index, flags); if (!page) return -ENOMEM; - *pagep = page; - if (!PageUptodate(page) && (len != PAGE_CACHE_SIZE)) { - unsigned from = pos & (PAGE_CACHE_SIZE - 1); - - zero_user_segments(page, 0, from, from + len, PAGE_CACHE_SIZE); + if (!PageUptodate(page)) { + unsigned from; + + if (PageTransHuge(page) && len != HPAGE_PMD_SIZE) { + from = pos & ~HPAGE_PMD_MASK; + zero_huge_user_segments(page, 0, from, + from + len, HPAGE_PMD_SIZE); + } else if (len != PAGE_CACHE_SIZE) { + from = pos & ~PAGE_CACHE_MASK; + zero_user_segments(page, 0, from, + from + len, PAGE_CACHE_SIZE); + } } return 0; } @@ -443,9 +466,14 @@ int simple_write_end(struct file *file, struct address_space *mapping, /* zero the stale part of the page if we did a short copy */ if (copied < len) { - unsigned from = pos & (PAGE_CACHE_SIZE - 1); - - zero_user(page, from + copied, len - copied); + unsigned from; + if (PageTransHuge(page)) { + from = pos & ~HPAGE_PMD_MASK; + zero_huge_user(page, from + copied, len - copied); + } else { + from = pos & ~PAGE_CACHE_MASK; + zero_user(page, from + copied, len - copied); + } } if (!PageUptodate(page)) -- 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/