Re: [9front] Slow cp, support for 9P2000.s

[aiju <aiju@phicode.de>]

None of the main team use reddit for Plan 9 stuff, afaik.

9P2020 (fwiw, not the only name that's been used) has been discussed on 
IRC (freenode, #cat-v) extensively in the past.

aiju

On Fri, 24 Apr 2020, Romano wrote:

> Thank you, Aiju!
> 
> Using fcp , I get 0.36u 0.70s 25.66r, so more than halving the time. And in retrospect I should have read the man page for cp first, where I would have seen fcp.
> 
> I lurk on reddit.com, so no account. I see there's reddit.com/r/9P2020, but it's private. Is the discussion re: 9P2020 mostly there, or elsewhere? I grepped 9P2020 under /n/lists/9front and only saw your message to me.
> 
> 
> 
> On April 24, 2020 4:28:15 AM UTC, aiju <aiju@phicode.de> wrote:
> >Yes his solution has been discussed and found wanting. If I remember
> >right 
> >it breaks the syscall interface and forces 9P to run over TCP.
> >
> >There have been ongoing talks about our own protocol 9P2020 to solve
> >this 
> >problem, but little progress because it's a hard problem to solve
> >properly 
> >without messing up Plan 9 too much.
> >
> >In the meantime, `fcp` is fast cp.
> >
> >- aiju
> >
> >
> >
> >On Fri, 24 Apr 2020, Romano wrote:
> >
> >> On my local wireless network at home between my work laptop and my
> >rpi 4, I tested using 'cp' while in drawterm.  I ran drawterm -G on my
> >rpi, and used srvfs to export its file system. I ran drawterm on my
> >work laptop, and mounted the exported filesystem as /n/pi.  I then
> >timed a 20MB file from /mnt/term/root/ on my work laptop to the /n/pi:
> >0.20u 0.82s 70.14r. 70s is atrociously slow for a local copy when
> >compared to http or scp, so I decided to look to see if this was known
> >and if any work had been done on this problem for 9p.  I came across
> >John Floren's thesis from 2010[1] and his testing showed that increased
> >latency over 9p significantly increased the time files took to
> >transfer. He also shows modifications to 'cp' and 'exportfs' to allow
> >for streams to make 9p have similar speeds as http.
> >>
> >> So considering Floren's research, I then decided to look at my
> >latency on my local network, and sure enough, I'm getting the following
> >ping results (for 144 packets transmitted, with 1 packet lost):
> >round-trip min/avg/max/stddev = 2.273/15.264/497.869/44.018 ms . With
> >an average latency of 15ms, the time it took for  20MB file to transfer
> >over 9p roughly matches Floren's tests.
> >>
> >> I think that modifying 'cp' and 'exportfs' would resolve this problem
> >and will look at patching it per Floren's thesis to confirm.  Would
> >modifying 'cp' and 'exportfs' to allow for streams be something others
> >would be interested in? Or has this already been discussed and the
> >stream solution been found wanting for some technical reason? The
> >protocol, as mentioned in the paper, is called 9P2000.s. I don't see
> >that flavor listed here: http://9p.cat-v.org/implementations
> >>
> >> [1]
> >https://pdfs.semanticscholar.org/9b47/22e251df61b4abbe0da61720e57ac7b62f61.pdf
> >>
>