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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 6BD67C48BD7 for ; Thu, 27 Jun 2019 16:06:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 43CEF208E3 for ; Thu, 27 Jun 2019 16:06:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=intel-com.20150623.gappssmtp.com header.i=@intel-com.20150623.gappssmtp.com header.b="vp6g94SZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726472AbfF0QG3 (ORCPT ); Thu, 27 Jun 2019 12:06:29 -0400 Received: from mail-oi1-f193.google.com ([209.85.167.193]:44737 "EHLO mail-oi1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726441AbfF0QG3 (ORCPT ); Thu, 27 Jun 2019 12:06:29 -0400 Received: by mail-oi1-f193.google.com with SMTP id e189so1947153oib.11 for ; Thu, 27 Jun 2019 09:06:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=aWIMvxomigHpjWeHK43P8bQp7hskbPyoEW4qUC++xwQ=; b=vp6g94SZAEhogB8+kASBrS83edW6InCqKko2xuhZZT36olRb9uNCLMVjLyfI6OQkYT 8otOEjJ/wDda0iFu+AgKq5gR4ZQdNDsgl1cId5NnnL1iJ/GvZXT6HuisMcGOClqUlIDC FjGSCO8bQLXY3sOuHvTq/VDGJlZgYzKRP7eKLh/seOIB2ogk0e13lnG4EjwF37n71ps/ zar5oshbh8IZ1AxD5brAYSbwVO6BQCN0DWQqcd2Fb8iQvPW8X62BL2WBnTS1MxzZQhxg ei8ENh0k8ProSrH8xiIDZSOUsBqFhCE5qcGcZDbva8PLP4urG/BUAIMh00/WAaoWm7Us XyXw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=aWIMvxomigHpjWeHK43P8bQp7hskbPyoEW4qUC++xwQ=; b=Jj+aOEvrd4YHAqwiIdMlrPNh42NXM22cdQIMLdKU8nn9JtJRQkJLCjsxFsdbXA0N1n bvZbJfvS6B1I4thXSHFMhm21WEb0KjPGBecXGZshxAJOKg0/lz5RJKMk6DorK+RE/AZm WFaO4Zn6cVX75iivAEeAJSQ9jEz/JRqtrRPtAD1wFWGsVMV1eM+5uP333CR+TbQumLdk qflG29hwVVRYCgYZU6hUSJNmdGmf4QN6LhWA5rIVRt3UKwF3w/kKmBfV/PijLSCP4gnM 9WzMPbRGW0m51eFdS1zPfqnWAD37Kmt+SJFkx90Qm7FyXZMni+JBiyPkYgUVwdhbpnsA DlIg== X-Gm-Message-State: APjAAAU3sIhKVBArBcz1HCgClEYytK+uUX18k/+1B+s6+pQHDSYzZCeu qcjqFaQgIAphkxclLRQgLZ4kxHUblZbpvy5/N0AAhw== X-Google-Smtp-Source: APXvYqxTBH4M/fPCrgDrZ+VdGZm5oRMIwhu+eQ9E/gvhgkhPtescyRRgvt8+s9jNs39vk0crvfXTrVskZyRmmvNYxVA= X-Received: by 2002:aca:fc50:: with SMTP id a77mr2695751oii.0.1561651588356; Thu, 27 Jun 2019 09:06:28 -0700 (PDT) MIME-Version: 1.0 References: <156159454541.2964018.7466991316059381921.stgit@dwillia2-desk3.amr.corp.intel.com> <20190627123415.GA4286@bombadil.infradead.org> In-Reply-To: <20190627123415.GA4286@bombadil.infradead.org> From: Dan Williams Date: Thu, 27 Jun 2019 09:06:17 -0700 Message-ID: Subject: Re: [PATCH] filesystem-dax: Disable PMD support To: Matthew Wilcox Cc: linux-nvdimm , Jan Kara , stable , Robert Barror , Seema Pandit , linux-fsdevel , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Thu, Jun 27, 2019 at 5:34 AM Matthew Wilcox wrote: > > 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. RocksDB in this case is using write() for writes and mmap() for reads.