From patchwork Tue Jul 26 00:35:14 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kirill A. Shutemov" X-Patchwork-Id: 652476 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3ryzqN4Gn1z9ssM for ; Tue, 26 Jul 2016 10:42:40 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755863AbcGZAgo (ORCPT ); Mon, 25 Jul 2016 20:36:44 -0400 Received: from mga09.intel.com ([134.134.136.24]:24743 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755511AbcGZAgM (ORCPT ); Mon, 25 Jul 2016 20:36:12 -0400 Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga102.jf.intel.com with ESMTP; 25 Jul 2016 17:35:57 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.28,421,1464678000"; d="scan'208";a="1002393720" Received: from black.fi.intel.com ([10.237.72.93]) by orsmga001.jf.intel.com with ESMTP; 25 Jul 2016 17:35:53 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id 41B976AD; Tue, 26 Jul 2016 03:35:47 +0300 (EEST) From: "Kirill A. Shutemov" To: "Theodore Ts'o" , Andreas Dilger , Jan Kara Cc: Alexander Viro , Hugh Dickins , Andrea Arcangeli , Andrew Morton , Dave Hansen , Vlastimil Babka , Matthew Wilcox , Ross Zwisler , linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-block@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCHv1, RFC 12/33] truncate: make sure invalidate_mapping_pages() can discard huge pages Date: Tue, 26 Jul 2016 03:35:14 +0300 Message-Id: <1469493335-3622-13-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.8.1 In-Reply-To: <1469493335-3622-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1469493335-3622-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org invalidate_inode_page() has expectation about page_count() of the page -- if it's not 2 (one to caller, one to radix-tree), it will not be dropped. That condition almost never met for THPs -- tail pages are pinned to the pagevec. Let's drop them, before calling invalidate_inode_page(). Signed-off-by: Kirill A. Shutemov --- mm/truncate.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/mm/truncate.c b/mm/truncate.c index a01cce450a26..ce904e4b1708 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -504,10 +504,21 @@ unsigned long invalidate_mapping_pages(struct address_space *mapping, /* 'end' is in the middle of THP */ if (index == round_down(end, HPAGE_PMD_NR)) continue; + /* + * invalidate_inode_page() expects + * page_count(page) == 2 to drop page from page + * cache -- drop tail pages references. + */ + get_page(page); + pagevec_release(&pvec); } ret = invalidate_inode_page(page); unlock_page(page); + + if (PageTransHuge(page)) + put_page(page); + /* * Invalidation is a hint that the page is no longer * of interest and try to speed up its reclaim.