From mboxrd@z Thu Jan 1 00:00:00 1970 From: Song Liu Subject: Re: Fw: some questions about uploading a Linux kernel driver Date: Thu, 30 Apr 2020 00:10:27 -0700 Message-ID: References: <6a7c0aba219642de8b3f1cc680d53d85@AM0P193MB0754.EURP193.PROD.OUTLOOK.COM> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Xiaosong Ma Cc: linux-raid , =?UTF-8?B?5aec5aSp5rSL?= , Guangyan Zhang , wei-jy19@mails.tsinghua.edu.cn List-Id: linux-raid.ids Hi Xiaosong, On Wed, Apr 22, 2020 at 5:26 AM Xiaosong Ma wrote: > > Dear Song, > > This is Xiaosong Ma from Qatar Computing Research Institute. I am > writing to follow up with the questions posed by a co-author from > Tsinghua U, regarding upstreaming our alternative md implementation > that is designed to significantly reduce SSD RAID latency (both median > and tail) for large SSD pools (such as 20-disk or more). > > We read the Linux kernel upstreaming instructions, and believe that > our implementation has excellent separability from the current code > base (as a plug-and-play module with identical interfaces as md). Plug-and-play is not the key for upstream new code/module. There are some other keys to consider: 1. Why do we need it? (better performance is a good reason here). 2. What's the impact on existing users? 3. Can we improve existing code to achieve the same benefit? > Meanwhile, we wonder whether there are standard test cases or > preferred applications that we should test our system with, before > doing code cleaning up. Your guidance is much appreciated. For testing, "mdadm test" is a good starting point (if it works here). We also need data integrity tests and stress tests. Thanks, Song