From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932183AbbKLPtN (ORCPT ); Thu, 12 Nov 2015 10:49:13 -0500 Received: from mail-ig0-f182.google.com ([209.85.213.182]:35618 "EHLO mail-ig0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751241AbbKLPtL (ORCPT ); Thu, 12 Nov 2015 10:49:11 -0500 Subject: Re: [PATCH] null_blk: Register as a LightNVM device To: Christoph Hellwig , Matias Bj??rling References: <1447236398-9421-1-git-send-email-m@bjorling.me> <20151112085327.GA28149@infradead.org> Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, axboe@fb.com From: Jens Axboe Message-ID: <5644B4F4.5090805@kernel.dk> Date: Thu, 12 Nov 2015 08:49:08 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <20151112085327.GA28149@infradead.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/12/2015 01:53 AM, Christoph Hellwig wrote: > On Wed, Nov 11, 2015 at 11:06:38AM +0100, Matias Bj??rling wrote: >> Add support for registering as a LightNVM device. This allows us to >> evaluate the performance of the LightNVM library. >> >> In /drivers/Makefile, LightNVM is moved above block device drivers >> to make sure that the LightNVM media managers have been initialized >> before drivers under /drivers/block are initialized. > > I don't think mixing the lighnvm code into null_blk is a good idea. > Please just create a separate null_nvm device for lighnvm. It already > has a completely separate I/O path. But it still avoids duplicating the generics of it. Patch for null_blk: 3 files changed, 168 insertions(+), 7 deletions (-) vs a standalone of: 3 files changed, 459 insertions(+) It doesn't screw up null_blk, so I'd prefer just adding it as an on-the-side mode for that. -- Jens Axboe