From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Kirill A. Shutemov" Subject: [PATCHv2, RFC 18/30] thp, mm: truncate support for transparent huge page cache Date: Thu, 14 Mar 2013 19:50:23 +0200 Message-ID: <1363283435-7666-19-git-send-email-kirill.shutemov@linux.intel.com> References: <1363283435-7666-1-git-send-email-kirill.shutemov@linux.intel.com> 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" To: Andrea Arcangeli , Andrew Morton , Al Viro , Hugh Dickins Return-path: Received: from mga11.intel.com ([192.55.52.93]:47422 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934539Ab3CNRtT (ORCPT ); Thu, 14 Mar 2013 13:49:19 -0400 In-Reply-To: <1363283435-7666-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: From: "Kirill A. Shutemov" If we starting position of truncation is in tail page we have to spilit the huge page page first. We also have to split if end is within the huge page. Otherwise we can truncate whole huge page at once. Signed-off-by: Kirill A. Shutemov --- mm/truncate.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/mm/truncate.c b/mm/truncate.c index c75b736..87c247d 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -231,6 +231,17 @@ void truncate_inode_pages_range(struct address_space *mapping, if (index > end) break; + /* split page if we start from tail page */ + if (PageTransTail(page)) + split_huge_page(compound_trans_head(page)); + if (PageTransHuge(page)) { + /* split if end is within huge page */ + if (index == (end & ~HPAGE_CACHE_INDEX_MASK)) + split_huge_page(page); + else + /* skip tail pages */ + i += HPAGE_CACHE_NR - 1; + } if (!trylock_page(page)) continue; WARN_ON(page->index != index); @@ -280,6 +291,7 @@ void truncate_inode_pages_range(struct address_space *mapping, if (index > end) break; + VM_BUG_ON(PageTransHuge(page)); lock_page(page); WARN_ON(page->index != index); wait_on_page_writeback(page); -- 1.7.10.4