On 2011-02-03 12:27, Gilles Chanteperdrix wrote: > Jan Kiszka wrote: >> On 2011-02-03 12:04, Gilles Chanteperdrix wrote: >>> Jan Kiszka wrote: >>>> [ And, personally, I don't trust the NVIDIA driver a lot. But that might >>>> be influenced by the fact that latest versions lock up my notebook >>>> regularly after resume and that I filed another obvious locking issue of >>>> the compilable driver stub around mmap_sem without any response from the >>>> vendor. ] >>> Some colleague of mine is using the NVIDIA driver (through the opengl >>> mapping, not CUDA/VDPAU, whatever) on high-end NVIDIA boards in a non RT >>> situation. he definitely observed some huge latencies not due to >>> scheduling issues, when uploading textures to the GPU. We are talking >>> tens of milliseconds here. >> >> Ugh, tens of milliseconds is heavy, more than I would expect from >> wbinvd. OTOH, uploading textures may involve mapping the RAM that >> contains them for the GPU. To exclude that as source, he could try >> instrumenting CACHE_FLUSH() (in nv-linux.h). > > No, it really looks like a bug in the blob. Of course the 40ms is a spot > from time to time, usually, the upload is really fast.
Unless it's a stall on the PCI bus, the blob should leaves some traces in ftrace. Anyway, the key message is the same: you don't know for sure what the blob is doing. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux _______________________________________________ Xenomai-help mailing list [email protected] https://mail.gna.org/listinfo/xenomai-help
