From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753654Ab3HDCPb (ORCPT ); Sat, 3 Aug 2013 22:15:31 -0400 Received: from mga09.intel.com ([134.134.136.24]:56722 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753530Ab3HDCOc (ORCPT ); Sat, 3 Aug 2013 22:14:32 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.89,810,1367996400"; d="scan'208";a="357029435" 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 , Ning Qu , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCH 14/23] thp, mm: naive support of thp in generic_perform_write Date: Sun, 4 Aug 2013 05:17:16 +0300 Message-Id: <1375582645-29274-15-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1375582645-29274-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1375582645-29274-1-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 From: "Kirill A. Shutemov" For now we still write/read at most PAGE_CACHE_SIZE bytes a time. This implementation doesn't cover address spaces with backing storage. Signed-off-by: Kirill A. Shutemov --- mm/filemap.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/mm/filemap.c b/mm/filemap.c index b17ebb9..066bbff 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2382,6 +2382,7 @@ static ssize_t generic_perform_write(struct file *file, unsigned long bytes; /* Bytes to write to page */ size_t copied; /* Bytes copied from user */ void *fsdata; + int subpage_nr = 0; offset = (pos & (PAGE_CACHE_SIZE - 1)); bytes = min_t(unsigned long, PAGE_CACHE_SIZE - offset, @@ -2411,8 +2412,14 @@ again: if (mapping_writably_mapped(mapping)) flush_dcache_page(page); + if (PageTransHuge(page)) { + off_t huge_offset = pos & ~HPAGE_PMD_MASK; + subpage_nr = huge_offset >> PAGE_CACHE_SHIFT; + } + pagefault_disable(); - copied = iov_iter_copy_from_user_atomic(page, i, offset, bytes); + copied = iov_iter_copy_from_user_atomic(page + subpage_nr, i, + offset, bytes); pagefault_enable(); flush_dcache_page(page); -- 1.8.3.2