From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4F940D6C.70108@domain.hid> Date: Sun, 22 Apr 2012 15:53:48 +0200 From: Wolfgang Grandegger MIME-Version: 1.0 References: <4F931496.1060607@domain.hid> <4F93CAF4.9050105@domain.hid> <4F93EA6D.5050208@domain.hid> <4F93ECCF.5020108@domain.hid> In-Reply-To: <4F93ECCF.5020108@domain.hid> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-help] linux 2.6.11 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 04/22/2012 01:34 PM, Gilles Chanteperdrix wrote: > On 04/22/2012 01:24 PM, Gilles Chanteperdrix wrote: >> On 04/22/2012 11:10 AM, Wolfgang Grandegger wrote: >>> But all this does not explain a factor of 3 with your driver. I doubt >>> that it's due to a move from 2.6.29 -> 2.6.32. Try using ftrace to find >>> out what's going on (if it's already available). >> >> Threaded interrupts were introduced around this time. And threaded >> interrupts DO have a significant impact on latencies. Yes, but thread interrupts are normally not enabled/used by default. I'm not speaking about CONFIG_PREEMPT_RT. Well, do we speak about latencies? He just said "reading an ADC on an EP9312 ARM board has slowed by a factor of three". I'm not even sure if it's related to Xenomai at all. xenophile (&$#^?) , could you please be more precise. > But I agree: tracing with ftrace or the I-pipe tracer if using xenomai > to see where the time is spent is the way to go. Yep. Wolfgang.