From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 500B7C48BD7 for ; Thu, 27 Jun 2019 12:34:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 280182086D for ; Thu, 27 Jun 2019 12:34:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="GB++/qHL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726589AbfF0MeS (ORCPT ); Thu, 27 Jun 2019 08:34:18 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:38506 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726059AbfF0MeS (ORCPT ); Thu, 27 Jun 2019 08:34:18 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=QQUdy9qv7ABtkbJ3dGIuBeaEJk7dGMp7ONsxEfM/sUo=; b=GB++/qHL9hKxCF/RRNMnajjsu xKIvNL4xju2zGJKLaeidmxAup1NRvdhZjR3qz5yxAEki0voDqhp3K+7wBftYKcCS72jZrOA4UebYR 6L73m6dtLHtZnrVEgDp+vgb4NX2jCDSJ9Wkb8IubBlfTXdwBFfLTnU/lJAH6LMyDKYsLpBbJO1qgw lgCL8lJdNVBxGDTi+PaQfAnimGwjCx09EVneNK413YhsRaMygyBBhgr74JEXnMhv92HXfD4mqTLlZ y4VGOKeHb8nEXmqYQzy2b65mZZ7IR8LavdkAcrSMkldtnd15+4M6uzfMhCcV+Okn/QUGtYvSJY5gx QaMJ3DiKw==; Received: from willy by bombadil.infradead.org with local (Exim 4.92 #3 (Red Hat Linux)) id 1hgTbT-00045v-KE; Thu, 27 Jun 2019 12:34:15 +0000 Date: Thu, 27 Jun 2019 05:34:15 -0700 From: Matthew Wilcox To: Dan Williams Cc: linux-nvdimm@lists.01.org, Jan Kara , stable@vger.kernel.org, Robert Barror , Seema Pandit , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] filesystem-dax: Disable PMD support Message-ID: <20190627123415.GA4286@bombadil.infradead.org> References: <156159454541.2964018.7466991316059381921.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <156159454541.2964018.7466991316059381921.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Jun 26, 2019 at 05:15:45PM -0700, Dan Williams wrote: > 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. On May 4th, I asked you: Since this is provoked by a fatal signal, it must have something to do with a killable or interruptible sleep. There's only one of those in the DAX code; fatal_signal_pending() in dax_iomap_actor(). Does rocksdb do I/O with write() or through a writable mmap()? I'd like to know before I chase too far down this fault tree analysis.