From: Matthew Wilcox <willy@infradead.org>
To: Amit Golander <amit@plexistor.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>,
Amir Goldstein <amir73il@gmail.com>,
Amit Golander <Amit.Golander@netapp.com>,
Andy Rudof <andy.rudoff@intel.com>,
Anna Schumaker <Anna.Schumaker@netapp.com>,
Boaz Harrosh <boazh@netapp.com>, Jan Kara <jack@suse.cz>,
Jefff moyer <jmoyer@redhat.com>,
Ric Wheeler <rwheeler@redhat.com>, Sage Weil <sweil@redhat.com>,
Sagi Manole <sagim@netapp.com>,
Shachar Sharon <Shachar.Sharon@netapp.com>,
Steve French <smfrench@gmail.com>,
Steven Whitehouse <swhiteho@redhat.com>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: [RFC 1/7] mm: Add new vma flag VM_LOCAL_CPU
Date: Wed, 14 Mar 2018 09:48:25 -0700 [thread overview]
Message-ID: <20180314164825.GI29631@bombadil.infradead.org> (raw)
In-Reply-To: <CAON-v2ygEDCn90C9t-zadjsd5GRgj0ECqntQSDDtO_Zjk=KoVw@mail.gmail.com>
On Wed, Mar 14, 2018 at 04:27:20PM +0000, Amit Golander wrote:
> ZUFS is not intended or designed to replace FUSE. Just like RDMA is not
> intended to replace TCP.
Your intent is to have two independent approaches to permitting
filesystems-in-userspace to exist. And I've pointed out that your
approach doesn't work for my use-case (and neither does FUSE). While we
might accept two implementations of something, at the point that three
implementations are proposed, we usually say "No, come up with a better
solution that works for everybody".
> On Wed, 14 Mar 2018 at 8:39 Miklos Szeredi <mszeredi@redhat.com> wrote:
>
> > On Wed, Mar 14, 2018 at 3:57 PM, Matthew Wilcox <willy@infradead.org>
> > wrote:
> > > On Wed, Mar 14, 2018 at 03:49:35PM +0100, Miklos Szeredi wrote:
> > >> On Wed, Mar 14, 2018 at 12:45 PM, Matthew Wilcox <willy@infradead.org>
> > wrote:
> > >> > Erm ... there's nothing wrong with having one pipe per CPU. But pipes
> > >> > being non-seekable means that ZUFS can only handle synchronous I/Os.
> > >> > If you want to have a network backend, then you'd only be able to have
> > >> > one outstanding network request per pipe, which is really going to
> > suck
> > >> > for bandwidth.
> > >>
> > >> I guess ZUFS is mostly about fast synchronous access (please correct
> > >> me if I'm wrong). Not sure that model fits network filesystems, where
> > >> performance of caching will dominate real life performance.
> > >
> > > I'm sure that's Boaz's use case ;-) But if we're introducing
> > > a replacement for FUSE, let's make it better than FUSE, not just
> > > specialised to Boaz's use case.
> >
> > Okay, so the FUSE vs. ZUFS question was bound to be raised at some
> > point. What's the high level thinking on this?
> >
> > We can make ZUFS be a better FUSE, but with a new API? New API means
> > we'll lose existing user base. Having a new API but adding a compat
> > layer may be able to work around that, but it's probably hard to fully
> > emulate the old API.
> >
> > What are the limiting factors in the FUSE API that are preventing
> > fixing these performance problems in FUSE?
> >
> > Or it's just that FUSE kernel implementation is a horrid piece of
> > bloat (true) and we need to do something from scratch without worrying
> > about backward compat issues?
> >
> > Is ZUFS planning to acquire a caching layer?
> >
> > Btw, what is happening when a ZUFS file is mmaped?
> >
> > Thanks,
> > Miklos
> >
next prev parent reply other threads:[~2018-03-14 16:48 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-13 17:14 [RFC 0/7] first draft of ZUFS - the Kernel part Boaz Harrosh
2018-03-13 17:15 ` [RFC 1/7] mm: Add new vma flag VM_LOCAL_CPU Boaz Harrosh
2018-03-13 18:56 ` Matthew Wilcox
2018-03-14 8:20 ` Miklos Szeredi
2018-03-14 11:17 ` Matthew Wilcox
2018-03-14 11:31 ` Miklos Szeredi
2018-03-14 11:45 ` Matthew Wilcox
2018-03-14 14:49 ` Miklos Szeredi
2018-03-14 14:57 ` Matthew Wilcox
2018-03-14 15:39 ` Miklos Szeredi
[not found] ` <CAON-v2ygEDCn90C9t-zadjsd5GRgj0ECqntQSDDtO_Zjk=KoVw@mail.gmail.com>
2018-03-14 16:48 ` Matthew Wilcox [this message]
2018-03-14 21:41 ` Boaz Harrosh
2018-03-15 8:47 ` Miklos Szeredi
2018-03-15 15:27 ` Boaz Harrosh
2018-03-15 15:34 ` Matthew Wilcox
2018-03-15 15:58 ` Boaz Harrosh
2018-03-15 16:10 ` Miklos Szeredi
2018-03-15 16:30 ` Boaz Harrosh
2018-03-15 20:42 ` Miklos Szeredi
2018-04-25 12:21 ` Boaz Harrosh
2018-05-07 10:46 ` Miklos Szeredi
2018-03-13 17:17 ` [RFC 2/7] fs: Add the ZUF filesystem to the build + License Boaz Harrosh
2018-03-13 20:16 ` Andreas Dilger
2018-03-14 17:21 ` Boaz Harrosh
2018-03-15 4:21 ` Andreas Dilger
2018-03-15 13:58 ` Boaz Harrosh
2018-03-13 17:18 ` [RFC 3/7] zuf: Preliminary Documentation Boaz Harrosh
2018-03-13 20:32 ` Randy Dunlap
2018-03-14 18:01 ` Boaz Harrosh
2018-03-14 19:16 ` Randy Dunlap
2018-03-13 17:22 ` [RFC 4/7] zuf: zuf-rootfs && zuf-core Boaz Harrosh
2018-03-13 17:36 ` Boaz Harrosh
2018-03-14 12:56 ` Nikolay Borisov
2018-03-14 18:34 ` Boaz Harrosh
2018-03-13 17:25 ` [RFC 5/7] zus: Devices && mounting Boaz Harrosh
2018-03-13 17:38 ` Boaz Harrosh
2018-03-13 17:28 ` [RFC 6/7] zuf: Filesystem operations Boaz Harrosh
2018-03-13 17:39 ` Boaz Harrosh
2018-03-13 17:32 ` [RFC 7/7] zuf: Write/Read && mmap implementation Boaz Harrosh
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