From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [GIT PULL v4 00/21] libnd: non-volatile memory device support Date: Wed, 3 Jun 2015 08:55:10 +0200 Message-ID: <20150603065510.GB11344@lst.de> References: <20150527210155.17965.74864.stgit@dwillia2-desk3.amr.corp.intel.com> <20150528085124.GA26120@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from verein.lst.de ([213.95.11.211]:50541 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751481AbbFCGzN (ORCPT ); Wed, 3 Jun 2015 02:55:13 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Dan Williams Cc: Christoph Hellwig , Jens Axboe , Boaz Harrosh , Neil Brown , Dave Chinner , Lv Zheng , "H. Peter Anvin" , Stephen Rothwell , "linux-nvdimm@lists.01.org" , "Rafael J. Wysocki" , Robert Moore , Ingo Molnar , Linux ACPI , jmoyer , Nicholas Moulin , Matthew Wilcox , Ross Zwisler , Vishal Verma , Jens Axboe , Borislav Petkov , Thomas Gleixner , Greg KH , "linux-kernel@vger.kernel.org" On Thu, May 28, 2015 at 07:55:47AM -0700, Dan Williams wrote: > > - stong NAK for the linker wrapping abuse in the test module >=20 > This capability has been our single largest generator of bug fixes an= d > regression prevention. Please tell me you have a non-bikeshed > argument why this test approach must die? We need more tests in tree= , > not less. That said, it's at the end of the series ready to be loppe= d > off like a spent booster rocket if it's really a blocker. No - you're overloading general functionality to go to something much slower, with locking implications etc totally invisible to someone read= ing the code. I could be persuaded that a test module makes sense if you make it an explicit opt-in at the source code level, e.g. a version of a the pmem driver that needs to be explicitly loaded. Then again I really don't see the point - if you already need a VM with ACPI / EFI tables to claim that you have pmem support you might as well do the pmem emulation in that same virtual=D1=96zation environment. > It makes the identifier prefixes shorter is the bulk of the reasoning > and a hardware memory resource need not always be a "dimm". If it's > just the top-level directory I'm fine with 'nvdimm' or are you lookin= g > for a rename throughout? That's the most important part. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 3 Jun 2015 08:55:10 +0200 From: Christoph Hellwig Subject: Re: [GIT PULL v4 00/21] libnd: non-volatile memory device support Message-ID: <20150603065510.GB11344@lst.de> References: <20150527210155.17965.74864.stgit@dwillia2-desk3.amr.corp.intel.com> <20150528085124.GA26120@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Dan Williams Cc: Christoph Hellwig , Jens Axboe , Boaz Harrosh , Neil Brown , Dave Chinner , Lv Zheng , "H. Peter Anvin" , Stephen Rothwell , "linux-nvdimm@lists.01.org" , "Rafael J. Wysocki" , Robert Moore , Ingo Molnar , Linux ACPI , jmoyer , Nicholas Moulin , Matthew Wilcox , Ross Zwisler , Vishal Verma , Jens Axboe , Borislav Petkov , Thomas Gleixner , Greg KH , "linux-kernel@vger.kernel.org" , Andy Lutomirski , Andrew Morton , Linus Torvalds List-ID: On Thu, May 28, 2015 at 07:55:47AM -0700, Dan Williams wrote: > > - stong NAK for the linker wrapping abuse in the test module > > This capability has been our single largest generator of bug fixes and > regression prevention. Please tell me you have a non-bikeshed > argument why this test approach must die? We need more tests in tree, > not less. That said, it's at the end of the series ready to be lopped > off like a spent booster rocket if it's really a blocker. No - you're overloading general functionality to go to something much slower, with locking implications etc totally invisible to someone reading the code. I could be persuaded that a test module makes sense if you make it an explicit opt-in at the source code level, e.g. a version of a the pmem driver that needs to be explicitly loaded. Then again I really don't see the point - if you already need a VM with ACPI / EFI tables to claim that you have pmem support you might as well do the pmem emulation in that same virtualіzation environment. > It makes the identifier prefixes shorter is the bulk of the reasoning > and a hardware memory resource need not always be a "dimm". If it's > just the top-level directory I'm fine with 'nvdimm' or are you looking > for a rename throughout? That's the most important part. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753080AbbFCGzV (ORCPT ); Wed, 3 Jun 2015 02:55:21 -0400 Received: from verein.lst.de ([213.95.11.211]:50541 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751481AbbFCGzN (ORCPT ); Wed, 3 Jun 2015 02:55:13 -0400 Date: Wed, 3 Jun 2015 08:55:10 +0200 From: Christoph Hellwig To: Dan Williams Cc: Christoph Hellwig , Jens Axboe , Boaz Harrosh , Neil Brown , Dave Chinner , Lv Zheng , "H. Peter Anvin" , Stephen Rothwell , "linux-nvdimm@lists.01.org" , "Rafael J. Wysocki" , Robert Moore , Ingo Molnar , Linux ACPI , jmoyer , Nicholas Moulin , Matthew Wilcox , Ross Zwisler , Vishal Verma , Jens Axboe , Borislav Petkov , Thomas Gleixner , Greg KH , "linux-kernel@vger.kernel.org" , Andy Lutomirski , Andrew Morton , Linus Torvalds Subject: Re: [GIT PULL v4 00/21] libnd: non-volatile memory device support Message-ID: <20150603065510.GB11344@lst.de> References: <20150527210155.17965.74864.stgit@dwillia2-desk3.amr.corp.intel.com> <20150528085124.GA26120@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 28, 2015 at 07:55:47AM -0700, Dan Williams wrote: > > - stong NAK for the linker wrapping abuse in the test module > > This capability has been our single largest generator of bug fixes and > regression prevention. Please tell me you have a non-bikeshed > argument why this test approach must die? We need more tests in tree, > not less. That said, it's at the end of the series ready to be lopped > off like a spent booster rocket if it's really a blocker. No - you're overloading general functionality to go to something much slower, with locking implications etc totally invisible to someone reading the code. I could be persuaded that a test module makes sense if you make it an explicit opt-in at the source code level, e.g. a version of a the pmem driver that needs to be explicitly loaded. Then again I really don't see the point - if you already need a VM with ACPI / EFI tables to claim that you have pmem support you might as well do the pmem emulation in that same virtualіzation environment. > It makes the identifier prefixes shorter is the bulk of the reasoning > and a hardware memory resource need not always be a "dimm". If it's > just the top-level directory I'm fine with 'nvdimm' or are you looking > for a rename throughout? That's the most important part.