Quoting Daniel Vetter (2021-07-02 23:17:08) > We're not consistently recommending these for developers only. > > I stumbled over this due to DRM_I915_LOW_LEVEL_TRACEPOINTS, which was > added in > > commit 354d036fcf70654cff2e2cbdda54a835d219b9d2 > Author: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> > Date: Tue Feb 21 11:01:42 2017 +0000 > > drm/i915/tracepoints: Add request submit and execute tracepoints > > to "alleviate the performance impact concerns." > > Which is nonsense. I think that was the original reason why the patch was developed and it got merged primarily for the latter reason. Unfortunately the patch commit messages don't always get rewritten. > Tvrtko and Joonas pointed out on irc that the real (but undocumented > reason) was stable abi concerns for tracepoints, see > > https://lwn.net/Articles/705270/ > > and the specific change that was blocked around tracepoints: > > https://lwn.net/Articles/442113/ > > Anyway to make it a notch clearer why we have this Kconfig option > consistly add the "Recommended for driver developers only." to it and > all the other debug options we have. > > Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> > Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> > Cc: Matthew Brost <matthew.brost@xxxxxxxxx> > Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> Regards, Joonas > --- > drivers/gpu/drm/i915/Kconfig.debug | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/gpu/drm/i915/Kconfig.debug b/drivers/gpu/drm/i915/Kconfig.debug > index 2ca88072d30f..f27c0b5873f7 100644 > --- a/drivers/gpu/drm/i915/Kconfig.debug > +++ b/drivers/gpu/drm/i915/Kconfig.debug > @@ -215,6 +215,8 @@ config DRM_I915_LOW_LEVEL_TRACEPOINTS > This provides the ability to precisely monitor engine utilisation > and also analyze the request dependency resolving timeline. > > + Recommended for driver developers only. > + > If in doubt, say "N". > > config DRM_I915_DEBUG_VBLANK_EVADE > @@ -228,6 +230,8 @@ config DRM_I915_DEBUG_VBLANK_EVADE > is exceeded, even if there isn't an actual risk of missing > the vblank. > > + Recommended for driver developers only. > + > If in doubt, say "N". > > config DRM_I915_DEBUG_RUNTIME_PM > @@ -240,4 +244,6 @@ config DRM_I915_DEBUG_RUNTIME_PM > runtime PM functionality. This may introduce overhead during > driver loading, suspend and resume operations. > > + Recommended for driver developers only. > + > If in doubt, say "N" > -- > 2.32.0.rc2 >
