[Intel-gfx] [PATCH] drm/i915: Skip logging impossible slices

[Chris Wilson]

Quoting Joonas Lahtinen (2018-03-23 12:29:54)
> Quoting Jani Nikula (2018-03-21 14:16:37)
> > On Wed, 21 Mar 2018, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> > > Quoting Jani Nikula (2018-03-21 11:47:06)
> > >> 
> > >> > Quoting Chris Wilson (2018-03-21 10:41:37)
> > >> >> 
> > >> >> Just idly testing the waters...
> > >> >> 
> > >> >> In yaml, this would be
> > >> >>   "<indent>- slice%d: { subslices: %u, mask: 0x%04x }\n"
> > >> >
> > >> > Or if we keep the node name the same for easier parsing:
> > >> >
> > >> >       "<indent>- slice: { id:%u, subslices:%u, mask:0x%04x }\n"
> > >> 
> > >> I'm not against doing this, especially for gpu dumps.
> > >> 
> > >> Wouldn't json be easier to generate and parse? Or do you prefer the
> > >> slightly better human readability of yaml?
> > >
> > > I think for any of the debug output preferring to keep it as readable as
> > > possible is essential. libyaml isn't that hard to use, even for a
> > > beginner like myself.
> > 
> > Fair enough; I'm only familiar with json, and that's my natural reason
> > to lean towards it.
> 
> JSON gets irritating to look at by plain eye. So I would agree that YAML
> would serve better when developers are likely to scroll through the file
> contents manually, too.
> 
> Then some more random thoughts:
> 
> This discussion will of course bring closer the can of forms that when
> we've formalized the debugfs format, does somebody expect it to stay
> more stable than not?

The starting point is that we do want to transition to an
easier-to-extend file format for sysfs (the idea of it being
single-valued is long gone :) There having a stable interface is without
question, so getting the transition right is the challenge and then
maintaining the hierarchy such that it is backwards and forward
compatible with new content.

> Having a counterpart in IGT and making that always match kernel, would
> be the obvious way to keep things sane.

Imo, if we aren't parsing debugfs in igt, then they can be dead code
eliminated. So I expect yamlification to snow ball once we've got the
first few done and a good feel for how to design kernel/igt API to suite
us. Then it's just a matter of throwing each debugfs through a yamllint
:)
-Chris