Re: 9pfs developers docs

[Christian Schoenebeck]

On Montag, 1. Februar 2021 13:26:49 CET Greg Kurz wrote:
> On Mon, 01 Feb 2021 12:30:52 +0100
> 
> Christian Schoenebeck <qemu_oss@crudebyte.com> wrote:
> > On Montag, 1. Februar 2021 10:24:26 CET Greg Kurz wrote:
> > > On Sun, 31 Jan 2021 19:23:52 +0100
> > > 
> > > Christian Schoenebeck <qemu_oss@crudebyte.com> wrote:
> > > > Hi,
> > > 
> > > Hi Christian,
> > > 
> > > > I started setting up some developer documentation for 9pfs:
> > > >         https://wiki.qemu.org/Documentation/9p
> > > > 
> > > > Still quite a bunch that should be added (e.g. there should be a
> > > > section
> > > > about threads and coroutines), but at least it's a start ...
> > > 
> > > I agree that a bunch of other things should be documented, but that's
> > > definitely a great start. Thanks for doing this !
> > > 
> > > Just one remark on the topology diagram:
> > > 
> > > https://wiki.qemu.org/File:9pfs_topology.png
> > > 
> > > It gives the impression that the 9p transport and server can
> > > handle multiple guests, which they certainly don't : each
> > > 9p server lives in exactly one device which is exposed to
> > > exactly one guest.
> > 
> > Right, I haven't considered that the diagram might be interpreted that
> > way. My primary intention was to show the 3 main components of 9pfs from
> > design perspective and secondary showing that multiple guests can share
> > storage.
> > 
> > So what would be better: a) duplicating the server side in the diagram
> > (then the image might become a bit large in height), b) dropping the
> > multiple guests, c) making the issue with server instances clear in the
> > text?
> I'd rather go for b)

Updated the diagram on the wiki page.

To keep noise low, I won't send emails on further changes to that wiki page. 
If you want to be auto notified then just add yourself to the watch list 
there.

> > If there are other things that you might think should be outlined by
> > additional diagram(s) let me know, then I can add that in one rush.
> > 
> > --
> > 
> > BTW I'm no longer able to run the 'local' 9p tests, --slow doesn't work
> > for
> > me. If you don't have an idea what I might be missing, then I have to look
> > why the CLI parameter is not interpreted.
> 
> Is it that '-m slow' doesn't work when running 'qos-test' or
> that 'make check-qtest SPEEP=slow' doesn't run the slow tests ?

Ah, that's '-m slow', not '--slow'. Yeah, that works for qos-test. I added the 
'-m slow' switch to the wiki page as well.

For now I can live with that, as I am more commonly calling qos-test directly. 
But it would be nice if the slow tests would make it into the general chain of 
all QEMU tests accordingly again.

> The latter was discussed on IRC last year but I don't know if
> anyone has tried to investigate this yet.
> 
> Nov 24 11:36:53 <groug>       th_huth, Hi. FYI it seems that the meson 
> conversion
> kinda broke 'make check SPEED=slow'. Test programs aren't passed '-m slow'
> Nov 24 11:51:42 <f4bug>       th_huth: do you know who uses/tests SPEED=slow? 
> Nov
> 24 11:52:03 <f4bug>   th_huth: I thought this was a block-related feature 
Nov
> 24 11:52:44 <groug>   f4bug, it is supposedly used by gitlab CI
> Nov 24 11:52:59 <groug>       .gitlab-ci.yml:    MAKE_CHECK_ARGS: check-qtest
> SPEED=slow Nov 24 12:50:53 <th_huth>  groug, I'm also running make check
> SPEED=slow manually sometimes ... I guess that got lost in the conversion
> to ninja ... bonzini, did you ever try? Nov 24 12:51:03 <bonzini>     no it
> shouldn't
> Nov 24 12:51:21 <th_huth>     let me check...
> Nov 24 12:51:40 <bonzini>     ah, the tests are chosen correctly but -m slow 
is
> lost Nov 24 12:52:02 <groug>  yes that's what I see
> Nov 24 12:54:04 <groug>       bonzini, missing bits in scripts/mtest2make.py ?
> Nov 24 12:54:28 <bonzini>     groug: sort of, but assuming that all 
executables
> support -m slow wouldn't work
> 
> Cc'ing Thomas and Paolo for additional details.
> 
> > Best regards,
> > Christian Schoenebeck