From patchwork Thu Jun 27 00:15:45 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 11018589 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7726E13AF for ; Thu, 27 Jun 2019 00:30:07 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6714828A0D for ; Thu, 27 Jun 2019 00:30:07 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5B3C928A13; Thu, 27 Jun 2019 00:30:07 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, 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 035F328A10 for ; Thu, 27 Jun 2019 00:30:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726722AbfF0AaD (ORCPT ); Wed, 26 Jun 2019 20:30:03 -0400 Received: from mga12.intel.com ([192.55.52.136]:1257 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726669AbfF0AaC (ORCPT ); Wed, 26 Jun 2019 20:30:02 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Jun 2019 17:30:02 -0700 X-IronPort-AV: E=Sophos;i="5.63,421,1557212400"; d="scan'208";a="152848892" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.16]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Jun 2019 17:30:02 -0700 Subject: [PATCH] filesystem-dax: Disable PMD support From: Dan Williams To: linux-nvdimm@lists.01.org Cc: Matthew Wilcox , Jan Kara , stable@vger.kernel.org, Robert Barror , Seema Pandit , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Wed, 26 Jun 2019 17:15:45 -0700 Message-ID: <156159454541.2964018.7466991316059381921.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-2-gc94f MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Ever since the conversion of DAX to the Xarray a RocksDB benchmark has been encountering intermittent lockups. The backtraces always include the filesystem-DAX PMD path, multi-order entries have been a source of bugs in the past, and disabling the PMD path allows a test that fails in minutes to run for an hour. The regression has been bisected to "dax: Convert page fault handlers to XArray", but little progress has been made on the root cause debug. Unless / until root cause can be identified mark CONFIG_FS_DAX_PMD broken to preclude intermittent lockups. Reverting the Xarray conversion also works, but that change is too big to backport. The implementation is committed to Xarray at this point. Link: https://lore.kernel.org/linux-fsdevel/CAPcyv4hwHpX-MkUEqxwdTj7wCCZCN4RV-L4jsnuwLGyL_UEG4A@mail.gmail.com/ Fixes: b15cd800682f ("dax: Convert page fault handlers to XArray") Cc: Matthew Wilcox Cc: Jan Kara Cc: Reported-by: Robert Barror Reported-by: Seema Pandit Signed-off-by: Dan Williams --- fs/Kconfig | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/Kconfig b/fs/Kconfig index f1046cf6ad85..85eecd0d4c5d 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -66,6 +66,9 @@ config FS_DAX_PMD depends on FS_DAX depends on ZONE_DEVICE depends on TRANSPARENT_HUGEPAGE + # intermittent lockups since commit b15cd800682f "dax: Convert + # page fault handlers to XArray" + depends on BROKEN # Selected by DAX drivers that do not expect filesystem DAX to support # get_user_pages() of DAX mappings. I.e. "limited" indicates no support