Re: [PATCH v5 00/11] remove msize limit in virtio transport
From: Christian Schoenebeck
Date: Wed Jul 13 2022 - 04:57:06 EST
On Dienstag, 12. Juli 2022 23:13:16 CEST Dominique Martinet wrote:
> Alright; anything I didn't reply to looks good to me.
> Christian Schoenebeck wrote on Tue, Jul 12, 2022 at 04:35:54PM +0200:
> > OVERVIEW OF PATCHES:
> > * Patches 1..6 remove the msize limitation from the 'virtio' transport
> > (i.e. the 9p 'virtio' transport itself actually supports >4MB now,
> > tested
> > successfully with an experimental QEMU version and some dirty 9p Linux
> > client hacks up to msize=128MB).
> I have no problem with this except for the small nitpicks I gave, but
> would be tempted to delay this part for one more cycle as it's really
> independant -- what do you think?
Yes, I would also postpone the virtio patches towards subsequent release
> > * Patch 7 limits msize for all transports to 4 MB for now as >4MB would
> > need>
> > more work on 9p client level (see commit log of patch 7 for details).
> > * Patches 8..11 tremendously reduce unnecessarily huge 9p message sizes
> > and
> > therefore provide performance gain as well. So far, almost all 9p
> > messages
> > simply allocated message buffers exactly msize large, even for messages
> > that actually just needed few bytes. So these patches make sense by
> > themselves, independent of this overall series, however for this series
> > even more, because the larger msize, the more this issue would have hurt
> > otherwise.
> time-wise we're getting close to the merge window already (probably in 2
> weeks), how confident are you in this?
> I can take patches 8..11 in -next now and probably find some time to
> test over next weekend, are we good?
Well, I have tested them thoroughly, but nevertheless IMO someone else than me
should review patch 10 as well, and review whether the calculations for the
individual message types are correct. That's a bit of spec dictionary lookup.