From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:44898 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932526AbcETJlw (ORCPT ); Fri, 20 May 2016 05:41:52 -0400 Date: Fri, 20 May 2016 17:41:48 +0800 From: Xiong Zhou To: Dan Williams Cc: linux-nvdimm@ml01.01.org, Dave Hansen , linux-kernel@vger.kernel.org, hch@lst.de, linux-block@vger.kernel.org, Andrew Morton Subject: Re: [PATCH v3 2/5] /dev/dax, pmem: direct access to persistent memory Message-ID: <20160520094148.GE5035@dhcp12-144.nay.redhat.com> References: <146360496572.37439.6497663679891935585.stgit@dwillia2-desk3.amr.corp.intel.com> <146360497642.37439.12866290214925858506.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <146360497642.37439.12866290214925858506.stgit@dwillia2-desk3.amr.corp.intel.com> Sender: linux-block-owner@vger.kernel.org List-Id: linux-block@vger.kernel.org On Wed, May 18, 2016 at 01:56:16PM -0700, Dan Williams wrote: > Device DAX is the device-centric analogue of Filesystem DAX > (CONFIG_FS_DAX). It allows memory ranges to be allocated and mapped > without need of an intervening file system. Device DAX is strict, > precise and predictable. Specifically this interface: > > 1/ Guarantees fault granularity with respect to a given page size (pte, > pmd, or pud) set at configuration time. > > 2/ Enforces deterministic behavior by being strict about what fault > scenarios are supported. > > For example, by forcing MADV_DONTFORK semantics and omitting MAP_PRIVATE > support device-dax guarantees that a mapping always behaves/performs the > same once established. It is the "what you see is what you get" access > mechanism to differentiated memory vs filesystem DAX which has > filesystem specific implementation semantics. > > Persistent memory is the first target, but the mechanism is also > targeted for exclusive allocations of performance differentiated memory > ranges. > > This commit is limited to the base device driver infrastructure to > associate a dax device with pmem range. > > Cc: Jeff Moyer > Cc: Christoph Hellwig > Cc: Andrew Morton > Cc: Dave Hansen > Cc: Ross Zwisler > Signed-off-by: Dan Williams > --- > drivers/Kconfig | 2 > drivers/Makefile | 1 > drivers/dax/Kconfig | 25 +++ > drivers/dax/Makefile | 4 + > drivers/dax/dax.c | 253 +++++++++++++++++++++++++++++++++++ > drivers/dax/dax.h | 24 +++ > drivers/dax/pmem.c | 158 ++++++++++++++++++++++ An entry in MAINTAINERS for these new files ? Thanks, Xiong