From patchwork Fri Aug 12 18:37:56 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: 9277807 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 1609560780 for ; Fri, 12 Aug 2016 18:48:54 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0AE0128AD3 for ; Fri, 12 Aug 2016 18:48:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F39A028AD6; Fri, 12 Aug 2016 18:48:53 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9A8EA28AD3 for ; Fri, 12 Aug 2016 18:48:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752805AbcHLSsc (ORCPT ); Fri, 12 Aug 2016 14:48:32 -0400 Received: from mga04.intel.com ([192.55.52.120]:38911 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752511AbcHLSis (ORCPT ); Fri, 12 Aug 2016 14:38:48 -0400 Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga104.fm.intel.com with ESMTP; 12 Aug 2016 11:38:47 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.28,512,1464678000"; d="scan'208";a="1040186526" Received: from black.fi.intel.com ([10.237.72.93]) by fmsmga002.fm.intel.com with ESMTP; 12 Aug 2016 11:38:42 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id DAFE7330; Fri, 12 Aug 2016 21:38:33 +0300 (EEST) From: "Kirill A. Shutemov" To: "Theodore Ts'o" , Andreas Dilger , Jan Kara , Andrew Morton Cc: Alexander Viro , Hugh Dickins , Andrea Arcangeli , 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: [PATCHv2 13/41] truncate: make sure invalidate_mapping_pages() can discard huge pages Date: Fri, 12 Aug 2016 21:37:56 +0300 Message-Id: <1471027104-115213-14-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.8.1 In-Reply-To: <1471027104-115213-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1471027104-115213-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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.