From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4FC52AF0.6040006@piments.com> Date: Tue, 29 May 2012 22:00:48 +0200 From: xenophile MIME-Version: 1.0 References: <4FC52889.8050002@piments.com> <4FC528F0.2070307@xenomai.org> In-Reply-To: <4FC528F0.2070307@xenomai.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai] What is the Xenomai time limit? List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gilles Chanteperdrix Cc: xenomai@xenomai.org On 05/29/12 21:52, Gilles Chanteperdrix wrote: > On 05/29/2012 09:50 PM, xenophile wrote: >> On 05/29/12 21:41, xenomai-owner@xenomai.org wrote: >>> >>> On 05/29/12 16:43, Philippe Gerum wrote: >>>> >>>> x86-wise, there is some more issues to keep an eye on: >>>> >>>> - Hyperthreading (not nice to -rt requirements) >>>> - SMI sources (causing IRQ-disabling BIOS code to be invoked directly by >>>> special interrupts not going through the programmable interrupt >>>> controller, so we can't block them, and don't know when they happen). >>>> - Some graphic card adapters (causing hw stalls to favor their own >>>> throughput) >>>> - Some graphic card drivers, most often proprietary, disabling >>>> interrupts for too long. >>>> - Some cycle-hungry x86 cache invalidation instructions (wbinv). >>>> - The legacy x86 PIT (i8254) when used, which goes through a legacy ISA >>>> bus, as expensive as ~1.5-2.5 us for each I/O access (you need at least >>>> two of them to program the next clock tick). Fortunately, you won't need >>>> it on a modern x86 platform, unless really unlucky. >>>> >>>> Oh well, other that that, x86 is almost fine for -rt stuff. >>>> >>> >> >> So what would be the best kind of x86 hardware to use for RT? >> >> Hyperthreading comes with multicore processors I think. >> >> What systems least SMI code ? >> >> My guess is that fast 32 bit x86 hardware like top of range AMD Athlon >> processors would be good (better than multicore 64 bit ) but I'm only >> guessing. >> >> Are fast graphics cards better, so long as they can be run without >> proprietary drivers ? >> >> I'm sure there's no hard and fast answer but can you offer any guide >> lines? >> >> Thx. > > The address of the mailing list is xenomai@xenomai.org, not > xenomai-owner@xenomai.org > Sorry, I got a bounce because I originally sent the msg from the wrong email account my end (that bounce came from "owner"). I replied to the bounce with the correct sender, thinking it would go to the list , I did not notice that it was from xenomai-owner. So hopefully both sender and recipient are now correct and this will appear on the list. Phew.