From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f169.google.com ([209.85.223.169]:33929 "EHLO mail-io0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752363AbcBJQDs (ORCPT ); Wed, 10 Feb 2016 11:03:48 -0500 Received: by mail-io0-f169.google.com with SMTP id 9so25832923iom.1 for ; Wed, 10 Feb 2016 08:03:48 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20160210111414.GF12245@quack.suse.cz> References: <20160210111414.GF12245@quack.suse.cz> Date: Wed, 10 Feb 2016 08:03:47 -0800 Message-ID: Subject: Re: [Lsf-pc] [LSF/MM ATTEND] [LSF/MM TOPIC] NOVA: A log-structured file system for NVM From: Andiry Xu To: Jan Kara Cc: lsf-pc@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, andiry@gmail.com Content-Type: text/plain; charset=UTF-8 Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Wed, Feb 10, 2016 at 3:14 AM, Jan Kara wrote: > Hi, > > On Tue 09-02-16 22:15:00, Andiry Xu wrote: >> I would like to attend LSF/MM to present a new file system design for >> non-volatile main memories. > > Well, LSF/MM is based more on discussions than presentations. Also a lot of > people from LSF/MM will go to Vault so I don't think presenting at LSF/MM > would make much sense. But we register your attend request. > > Honza > Thank you Jan. >> The goal of NOVA is to provide high performance and strong consistency >> (atomic metadata, data, mmap updates) at the same time. >> >> Although NOVA is a LFS, as it targets a different memory technology, >> it looks very different from conventional LFS. Some of the key design >> decisions of NOVA include: >> >> Per-inode log: Each inode has a log, with tail pointer points to the >> latest committed entry. This allows for high concurrency and parallel >> log scanning. >> >> Log is a linked list: Allows for fine-grained, page-size granularity >> garbage collection. Also, allocating log space is easy since NOVA does >> not need to allocate large, contiguous space for logs. >> >> Cheap atomicity: To atomically append a log, NOVA simply appends the >> log entry and then updates the log tail pointer. To coordinate updates >> across logs, NOVA appends each log and journal the log tails to update >> all logs atomically. This mechanism has lower overhead than journaling >> (which doubles writes) and shadow paging (which causes cascade >> updates). >> >> Stores file data outside the log: NOVA appends metadata of writes to >> the log and handles file data in a copy-on-write way. This results in >> a shorter log, and garbage collection is simple and efficient, as NOVA >> never copies data in log cleaning. >> >> Highly scalable: NOVA has free list, journal and inode table at each >> CPU to avoid global locking and scalability bottlenecks. >> >> NOVA is available on GitHub: >> >> https://github.com/NVSL/NOVA >> >> And the paper of NOVA will appear in FAST 2016. I will also give a >> talk in the Vault conference. >> >> I'm also interested in any NVM/DAX related topics. Thank you. > -- > Jan Kara > SUSE Labs, CR