RE: [PATCH 3/3] tools/testing/cxl: Document test configurations

[Ira Weiny]

+Matthew Ho

Dan Williams wrote:
> Ira Weiny wrote:
> > The devices created, their relationship, and intended testing purpose is
> > not extremely clear, especially for those unfamiliar with cxl-test.
> > 
> > Document the purpose of each hierarchy.  Add ASCII art to show the
> > relationship of devices.  Group the device declarations together based
> > on the hierarchies.
> > 
> > Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
> > ---
> >  tools/testing/cxl/test/cxl.c | 75 ++++++++++++++++++++++++++++++++++++++++++--
> >  1 file changed, 73 insertions(+), 2 deletions(-)
> > 
> > diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
> > index bf00dc52fe96..bd38a5fb60ae 100644
> > --- a/tools/testing/cxl/test/cxl.c
> > +++ b/tools/testing/cxl/test/cxl.c
> > @@ -23,6 +23,31 @@ static int interleave_arithmetic;
> >  #define NR_CXL_PORT_DECODERS 8
> >  #define NR_BRIDGES (NR_CXL_HOST_BRIDGES + NR_CXL_SINGLE_HOST + NR_CXL_RCH)
> >  
> > +/*
> > + * Interleave testing
> > + *
> > + *             +---------------+                            +---------------+
> > + *             | host_bridge[0]|                            | host_bridge[1]|
> > + *             +-/---------\---+                            +--/---------\--+
> > + *             /-           -\                               /-           -\
> > + *           /-               -\                           /-               -\
> > + *   +-------------+         +-------------+       +-------------+      +-------------+
> > + *   |root_port[0] |         |root_port[1] |       |root_port[2] |      |root_port[3] |
> > + *   +------|------+         +------|------+       +------|------+      +------|------+
> > + *          |                       |                     |                    |
> > + *  +-------|-------+       +-------|-------+     +-------|-------+    +-------|-------+
> > + *  |switch_uport[0]|       |switch_uport[1]|     |switch_uport[2]|    |switch_uport[3]|
> > + *  +---|-------|---+       +---/-------|---+     +---/-------|---+    +---|-------\---+
> > + *      |       \              /        \            /        \            /        \
> > + * +----|----++--|------++---------++----|----++---------++----|----++----|----++---------+
> > + * |switch   ||switch   ||switch   ||switch   ||switch   ||switch   ||switch   ||switch   |
> > + * |_dport[0]||_dport[1]||_dport[2]||_dport[3]||_dport[4]||_dport[5]||_dport[6]||_dport[7]|
> > + * +----|----++--|------++----|----++----|----++----|----++----|----++----|----++----|----+
> > + *      |        |            |          |          |          |          |          |
> > + *  +---|--+   +-|----+   +---|--+   +---|--+    +--|---+  +---|--+   +---|--+   +---|--+
> > + *  |mem[0]|   |mem[1]|   |mem[2]|   |mem[3]|    |mem[4]|  |mem[5]|   |mem[6]|   |mem[7]|
> > + *  +------+   +------+   +------+   +------+    +------+  +------+   +------+   +------+
> > + */
> 
> Circling back to merge this I realize that the numbering is off. For
> example a snippet from "cxl list -BPT -b cxl_test"
> 
>     "ports:root3":[
>       {
>         "port":"port5",
>         "host":"cxl_host_bridge.1",
>         "depth":1,
>         "nr_dports":2,
>         "dports":[
>           {
>             "dport":"cxl_root_port.1",
>             "id":1
>           },
>           {
>             "dport":"cxl_root_port.3",
>             "id":3
>           }
>         ],
> 
> This is due to the modulo math at setup time. I only noticed this
> because I wanted a diagram to refer to when doing some recent
> extensions.

:-(  I did not realize this detail.

> 
> I wonder if we could just use "cxl list" to maintain this diagram, or
> maybe circle back and use this to keep an image up to date on a web page
> somewhere:
> 
> https://lore.kernel.org/linux-cxl/cover.1660895649.git.sunfishho12@xxxxxxxxx/

I forgot about this and this is a nice idea.  Did that support land?

Ira