Re: [RFC 00/16] NOVA: a new file system for persistent memory

From: Miklos Szeredi
Date: Mon Oct 09 2017 - 11:32:16 EST


On Thu, Aug 3, 2017 at 9:48 AM, Steven Swanson <swanson@xxxxxxxxxxxx> wrote:
> This is an RFC patch series that impements NOVA (NOn-Volatile memory
> Accelerated file system), a new file system built for PMEM.

Hi,

Thanks for posting.

I read the paper and the design looks nice. Then I looked at the
patches, but could not find a place to start, nor something I could
actually try out. So let me suggest some ways to make this more
reviewer/tester friendly:

1) try starting with something very simple yet working and supporting
the final layout
- no optimizations (one big lock, no per-cpu data, rcu, numa, etc support)
- no support for optional features (checksumming, NFS export, etc)
- missing mandatory features (e.g. just readdir and getattr support)
- try and get it down to <5k lines, preferably 2-3k

2) pointer to sources and instructions for trying it out without
special hardware

3) build on this minimal working version by
- adding mandatory features
- then adding optimizations

4) each patch should leave the tree in a compiling and working state
but should be small and easily reviewed

5) leave optional features and unimportant optimizations for a later
submission; try to make the patchset as small as you meaningfully can
(i.e. it should be fully working and demonstrate the capabilities and
performance, but nothing more).

Thanks,
Miklos