From mboxrd@z Thu Jan 1 00:00:00 1970 MIME-Version: 1.0 In-Reply-To: References: <4F951555.2070403@domain.hid> Date: Mon, 23 Apr 2012 13:07:23 +0200 Message-ID: From: Willy Lambert Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Subject: Re: [Xenomai-help] Smi workaround on ICH8M List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Philippe Gerum Cc: xenomai@xenomai.org 2012/4/23 Willy Lambert : > 2012/4/23 Philippe Gerum : >> On 04/23/2012 03:51 AM, Willy Lambert wrote: >>> >>> Hi, >>> >>> I have a message =A0in dmesg about SMI workaround : >>> Xenomai: SMI-enabled chipset found, but SMI workaround disabled >>> =A0 =A0 =A0 =A0 =A0(check CONFIG_XENO_HW_SMI_WORKAROUND). You may encou= nter >>> =A0 =A0 =A0 =A0 =A0high interrupt latencies! >>> >>> My kernel should be configured properly and following the "In case of >>> high latencies" of >>> http://www.xenomai.org/index.php/Configuring_x86_kernels thread, I did >>> some tests. >>> >>> Latency test is here (if it is us it should be ok no ?): >>> >> >> Yes, this looks ok, but you need to run this test longer, and try a few >> usual suspects like plugging in/out USB devices while doing so (e.g. mou= se, >> netdev). >> >> The point of this message is to tell you that your chipset is known to >> create latency issues in some cases (like most Intel chipset these days)= , >> but you did not enable the Xenomai code which works around such issues b= y >> shutting down problematic SMI sources. That may be right, or even requir= ed >> to leave all the SMI sources enabled (e.g. thermal control), but this mi= ght >> also lead to unacceptable latency spots. YMMV. >> >> This is basically a heads up message. >> >> -- >> Philippe. > > Ok, thanks for answers. > > I did the test again , playing with usb and using the stress program > to generate CPU load. The max latency for now is 15us in 4 mins. So I > think it will be ok to keep SMI on for the time. Please let me know if > this test is still stoo short. > ^C---|-----------|-----------|-----------|--------|------|---------------= ---------- > RTS| =A0 =A0 =A00.604| =A0 =A0 =A02.332| =A0 =A0 15.161| =A0 =A0 =A0 0| = =A0 =A0 0| =A0 =A000:03:59/00:03:59 > > Do you know by chance where I can found infos about SMI sources ? I > suppose it is not in the ICH8M docs, it would be in my board doc ? Or > have I a soft way to do this check so that I don't have to spend time > with my vendor which will obviously have hard time to answer that ? Btw is there any way to test latencies without xenomai (or in secondary mode) to compare ?