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: 11018587 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 A853A13AF for ; Thu, 27 Jun 2019 00:30:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 97E9228A0A for ; Thu, 27 Jun 2019 00:30:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8B57A28A10; Thu, 27 Jun 2019 00:30:05 +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=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 84D7C28A0A for ; Thu, 27 Jun 2019 00:30:04 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 51973212AAB6E; Wed, 26 Jun 2019 17:30:04 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=192.55.52.93; helo=mga11.intel.com; envelope-from=dan.j.williams@intel.com; receiver=linux-nvdimm@lists.01.org Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 2AB05212AAB65 for ; Wed, 26 Jun 2019 17:30:02 -0700 (PDT) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga102.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 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 X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jan Kara , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Robert Barror , Matthew Wilcox , linux-fsdevel@vger.kernel.org, Seema Pandit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" 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