Messages in this thread | | | Date | Wed, 12 Apr 2023 01:36:52 +0300 | Subject | Re: [Freedreno] [PATCH v2 0/2] drm: fdinfo memory stats | From | Dmitry Baryshkov <> |
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On 11/04/2023 21:28, Rob Clark wrote: > On Tue, Apr 11, 2023 at 10:36 AM Dmitry Baryshkov > <dmitry.baryshkov@linaro.org> wrote: >> >> On Tue, 11 Apr 2023 at 20:13, Rob Clark <robdclark@gmail.com> wrote: >>> >>> On Tue, Apr 11, 2023 at 9:53 AM Daniel Vetter <daniel@ffwll.ch> wrote: >>>> >>>> On Tue, Apr 11, 2023 at 09:47:32AM -0700, Rob Clark wrote: >>>>> On Mon, Apr 10, 2023 at 2:06 PM Rob Clark <robdclark@gmail.com> wrote: >>>>>> >>>>>> From: Rob Clark <robdclark@chromium.org> >>>>>> >>>>>> Similar motivation to other similar recent attempt[1]. But with an >>>>>> attempt to have some shared code for this. As well as documentation. >>>>>> >>>>>> It is probably a bit UMA-centric, I guess devices with VRAM might want >>>>>> some placement stats as well. But this seems like a reasonable start. >>>>>> >>>>>> Basic gputop support: https://patchwork.freedesktop.org/series/116236/ >>>>>> And already nvtop support: https://github.com/Syllo/nvtop/pull/204 >>>>> >>>>> On a related topic, I'm wondering if it would make sense to report >>>>> some more global things (temp, freq, etc) via fdinfo? Some of this, >>>>> tools like nvtop could get by trawling sysfs or other driver specific >>>>> ways. But maybe it makes sense to have these sort of things reported >>>>> in a standardized way (even though they aren't really per-drm_file) >>>> >>>> I think that's a bit much layering violation, we'd essentially have to >>>> reinvent the hwmon sysfs uapi in fdinfo. Not really a business I want to >>>> be in :-) >>> >>> I guess this is true for temp (where there are thermal zones with >>> potentially multiple temp sensors.. but I'm still digging my way thru >>> the thermal_cooling_device stuff) >> >> It is slightly ugly. All thermal zones and cooling devices are virtual >> devices (so, even no connection to the particular tsens device). One >> can either enumerate them by checking >> /sys/class/thermal/thermal_zoneN/type or enumerate them through >> /sys/class/hwmon. For cooling devices again the only enumeration is >> through /sys/class/thermal/cooling_deviceN/type. >> >> Probably it should be possible to push cooling devices and thermal >> zones under corresponding providers. However I do not know if there is >> a good way to correlate cooling device (ideally a part of GPU) to the >> thermal_zone (which in our case is provided by tsens / temp_alarm >> rather than GPU itself). >> >>> >>> But what about freq? I think, esp for cases where some "fw thing" is >>> controlling the freq we end up needing to use gpu counters to measure >>> the freq. >> >> For the freq it is slightly easier: /sys/class/devfreq/*, devices are >> registered under proper parent (IOW, GPU). So one can read >> /sys/class/devfreq/3d00000.gpu/cur_freq or >> /sys/bus/platform/devices/3d00000.gpu/devfreq/3d00000.gpu/cur_freq. >> >> However because of the components usage, there is no link from >> /sys/class/drm/card0 >> (/sys/devices/platform/soc@0/ae00000.display-subsystem/ae01000.display-controller/drm/card0) >> to /sys/devices/platform/soc@0/3d00000.gpu, the GPU unit. >> >> Getting all these items together in a platform-independent way would >> be definitely an important but complex topic. > > But I don't believe any of the pci gpu's use devfreq ;-) > > And also, you can't expect the CPU to actually know the freq when fw > is the one controlling freq. We can, currently, have a reasonable > approximation from devfreq but that stops if IFPC is implemented. And > other GPUs have even less direct control. So freq is a thing that I > don't think we should try to get from "common frameworks"
I think it might be useful to add another passive devfreq governor type for external frequencies. This way we can use the same interface to export non-CPU-controlled frequencies.
> > BR, > -R > >>> >>>> What might be needed is better glue to go from the fd or fdinfo to the >>>> right hw device and then crawl around the hwmon in sysfs automatically. I >>>> would not be surprised at all if we really suck on this, probably more >>>> likely on SoC than pci gpus where at least everything should be under the >>>> main pci sysfs device. >>> >>> yeah, I *think* userspace would have to look at /proc/device-tree to >>> find the cooling device(s) associated with the gpu.. at least I don't >>> see a straightforward way to figure it out just for sysfs >>> >>> BR, >>> -R >>> >>>> -Daniel >>>> >>>>> >>>>> BR, >>>>> -R >>>>> >>>>> >>>>>> [1] https://patchwork.freedesktop.org/series/112397/ >>>>>> >>>>>> Rob Clark (2): >>>>>> drm: Add fdinfo memory stats >>>>>> drm/msm: Add memory stats to fdinfo >>>>>> >>>>>> Documentation/gpu/drm-usage-stats.rst | 21 +++++++ >>>>>> drivers/gpu/drm/drm_file.c | 79 +++++++++++++++++++++++++++ >>>>>> drivers/gpu/drm/msm/msm_drv.c | 25 ++++++++- >>>>>> drivers/gpu/drm/msm/msm_gpu.c | 2 - >>>>>> include/drm/drm_file.h | 10 ++++ >>>>>> 5 files changed, 134 insertions(+), 3 deletions(-) >>>>>> >>>>>> -- >>>>>> 2.39.2 >>>>>> >>>> >>>> -- >>>> Daniel Vetter >>>> Software Engineer, Intel Corporation >>>> http://blog.ffwll.ch >> >> >> >> -- >> With best wishes >> Dmitry
-- With best wishes Dmitry
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