From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4D4A9052.2090508@domain.hid> Date: Thu, 03 Feb 2011 12:24:02 +0100 From: Jan Kiszka MIME-Version: 1.0 References: <4D4A84ED.7030604@domain.hid> <4D4A8BD8.1060900@domain.hid> In-Reply-To: <4D4A8BD8.1060900@domain.hid> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-help] RT OS Selection advice for parallel processing List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gilles Chanteperdrix Cc: "xenomai@xenomai.org" 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). Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux