From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ot0-f197.google.com (mail-ot0-f197.google.com [74.125.82.197]) by kanga.kvack.org (Postfix) with ESMTP id B7FAB6B0003 for ; Wed, 31 Jan 2018 20:03:20 -0500 (EST) Received: by mail-ot0-f197.google.com with SMTP id h8so11105159ote.8 for ; Wed, 31 Jan 2018 17:03:20 -0800 (PST) Received: from mail-sor-f41.google.com (mail-sor-f41.google.com. [209.85.220.41]) by mx.google.com with SMTPS id y20sor2321656otd.272.2018.01.31.17.03.19 for (Google Transport Security); Wed, 31 Jan 2018 17:03:19 -0800 (PST) MIME-Version: 1.0 In-Reply-To: References: From: Dan Williams Date: Wed, 31 Jan 2018 17:03:19 -0800 Message-ID: Subject: Re: [LSF/MM TOPIC] Native NVMM file systems Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: Andiry Xu Cc: lsf-pc@lists.linux-foundation.org, Linux FS Devel , Linux MM , "linux-nvdimm@lists.01.org" , david , Matthew Wilcox , swanson@cs.ucsd.edu, jix024@cs.ucsd.edu On Wed, Jan 31, 2018 at 4:45 PM, Andiry Xu wrote: > PMEM/DAX should allow for significant improvements in file system > performance and enable new programming models that allow direct, > efficient access to PMEM from userspace. Achieving these gains in > existing file systems built for block devices (e.g., XFS and EXT4=E2=80= =A6) > presents a range of challenges (e.g., > https://lkml.org/lkml/2016/9/11/159) and has been the subject of a lot > of recent work on ext4 and xfs. > > An alternative is to build a NVMM-aware file system from scratch that > takes full advantage of the performance that PMEM offers and avoids > the complexity that block-based file systems include to maximize > performance on slow storage (e.g., relaxing atomicity constraints on > many operations). Of course, it also brings with it the complexity of > another file system. > > We recently sent out a patch set for one-such =E2=80=9Cclean slate=E2=80= =9D NVMM-aware > file system called NOVA. NOVA is log-structured DAX file system with > several nice features: > > * High performance, especially in metadata operations due to efficient > fine-grained logging > * High scalability with per-CPU memory pool and per-inode logging > * Strong metadata and data atomicity guarantees for all operations > * Full filesystem snapshot support with DAX-mmap > * Metadata replication/checksums and RAID-4 style data protection > > At the summit, we would like to discuss the trade-offs between > adapting NVMM features to existing file systems vs. creating/adopting > a purpose-built file system for NVMM. NOVA serves as useful starting > point for that discussion by demonstrating what=E2=80=99s possible. It m= ay > also suggest some features that could be adapted to other file systems > to improve NVMM performance. > > We welcome people that are interested in file systems and NVM/DAX. > Particular people that would be useful to have in attendance are Dan > Williams, Dave Chinner, and Matthew Wilcox. The rest of the fs-dax crew would also be useful to have: Jan Kara Ross Zwisler -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org