Re: [RFC 0/2] virtio-pmem: Asynchronous flush

From: Dan Williams <dan.j.williams@intel.com>
To: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Cc: David Hildenbrand <david@redhat.com>,
	Pankaj Gupta <pankaj.gupta.linux@gmail.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-nvdimm <linux-nvdimm@lists.01.org>,
	Vishal L Verma <vishal.l.verma@intel.com>,
	Dave Jiang <dave.jiang@intel.com>,
	"Michael S. Tsirkin" <mst@redhat.com>, jmoyer <jmoyer@redhat.com>
Subject: Re: [RFC 0/2] virtio-pmem: Asynchronous flush
Date: Thu, 11 Mar 2021 22:02:52 -0800	[thread overview]
Message-ID: <CAPcyv4i4=2zT65Ym-sQv4gSa421q7FUAcX6Un3hf8=FW5qi3yw@mail.gmail.com> (raw)
In-Reply-To: <CALzYo33i5nBuPj4c3cJCZB9qEwfjypDqXf9vtn2wJdTYCFxg8g@mail.gmail.com>

On Thu, Mar 11, 2021 at 8:21 PM Pankaj Gupta
<pankaj.gupta@cloud.ionos.com> wrote:
>
> Hi David,
>
> > >   Jeff reported preflush order issue with the existing implementation
> > >   of virtio pmem preflush. Dan suggested[1] to implement asynchronous flush
> > >   for virtio pmem using work queue as done in md/RAID. This patch series
> > >   intends to solve the preflush ordering issue and also makes the flush
> > >   asynchronous from the submitting thread POV.
> > >
> > >   Submitting this patch series for feeback and is in WIP. I have
> > >   done basic testing and currently doing more testing.
> > >
> > > Pankaj Gupta (2):
> > >    pmem: make nvdimm_flush asynchronous
> > >    virtio_pmem: Async virtio-pmem flush
> > >
> > >   drivers/nvdimm/nd_virtio.c   | 66 ++++++++++++++++++++++++++----------
> > >   drivers/nvdimm/pmem.c        | 15 ++++----
> > >   drivers/nvdimm/region_devs.c |  3 +-
> > >   drivers/nvdimm/virtio_pmem.c |  9 +++++
> > >   drivers/nvdimm/virtio_pmem.h | 12 +++++++
> > >   5 files changed, 78 insertions(+), 27 deletions(-)
> > >
> > > [1] https://marc.info/?l=linux-kernel&m=157446316409937&w=2
> > >
> >
> > Just wondering, was there any follow up of this or are we still waiting
> > for feedback? :)
>
> Thank you for bringing this up.
>
> My apologies I could not followup on this. I have another version in my local
> tree but could not post it as I was not sure if I solved the problem
> correctly. I will
> clean it up and post for feedback as soon as I can.
>
> P.S: Due to serious personal/family health issues I am not able to
> devote much time
> on this with other professional commitments. I feel bad that I have
> this unfinished task.
> Just in last one year things have not been stable for me & my family
> and still not getting :(

No worries Pankaj. Take care of yourself and your family. The
community can handle this for you. I'm open to coaching somebody
through what's involved to get this fix landed.