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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham 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 67D54C43381 for ; Fri, 22 Feb 2019 23:11:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 40C5B206C0 for ; Fri, 22 Feb 2019 23:11:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726940AbfBVXLp (ORCPT ); Fri, 22 Feb 2019 18:11:45 -0500 Received: from ipmail06.adl6.internode.on.net ([150.101.137.145]:36908 "EHLO ipmail06.adl6.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725811AbfBVXLp (ORCPT ); Fri, 22 Feb 2019 18:11:45 -0500 Received: from ppp59-167-129-252.static.internode.on.net (HELO dastard) ([59.167.129.252]) by ipmail06.adl6.internode.on.net with ESMTP; 23 Feb 2019 09:41:43 +1030 Received: from dave by dastard with local (Exim 4.80) (envelope-from ) id 1gxJyi-0001Z4-KK; Sat, 23 Feb 2019 10:11:36 +1100 Date: Sat, 23 Feb 2019 10:11:36 +1100 From: Dave Chinner To: "Darrick J. Wong" Cc: dan.j.williams@intel.com, linux-nvdimm@lists.01.org, zwisler@kernel.org, vishal.l.verma@intel.com, xfs , linux-fsdevel Subject: Re: [RFC PATCH] pmem: advertise page alignment for pmem devices supporting fsdax Message-ID: <20190222231136.GC23020@dastard> References: <20190222182008.GT6503@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190222182008.GT6503@magnolia> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, Feb 22, 2019 at 10:20:08AM -0800, Darrick J. Wong wrote: > Hi all! > > Uh, we have an internal customer who's been trying out MAP_SYNC > on pmem, and they've observed that one has to do a fair amount of > legwork (in the form of mkfs.xfs parameters) to get the kernel to set up > 2M PMD mappings. They (of course) want to mmap hundreds of GB of pmem, > so the PMD mappings are much more efficient. > > I started poking around w.r.t. what mkfs.xfs was doing and realized that > if the fsdax pmem device advertised iomin/ioopt of 2MB, then mkfs will > set up all the parameters automatically. Below is my ham-handed attempt > to teach the kernel to do this. What's the before and after mkfs output? (need to see the context that this "fixes" before I comment) Cheers, Dave. -- Dave Chinner david@fromorbit.com