From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4C878E69.4030608@domain.hid> Date: Wed, 08 Sep 2010 15:23:53 +0200 From: Gilles Chanteperdrix MIME-Version: 1.0 References: <20100908111656.GA24409@domain.hid> <4C8779EA.5030506@domain.hid> In-Reply-To: <4C8779EA.5030506@domain.hid> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-help] XENO_HW_SMI_WORKAROUND safety List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Richard Cochran Cc: xenomai@xenomai.org Gilles Chanteperdrix wrote: > Richard Cochran wrote: >> As an x86 dummy, I have a question about XENO_HW_SMI_WORKAROUND and >> XENO_HW_SMI_ALL. I remember from the 2009 RTLW, that Thomas Gleixner >> said not to disable SMIs or it might melt my cpu. >> >> Is there any risk in enabling the Xenomai options? > > Some people seem to have used it without any problem. The problem > happens if SMIs are used for regulating the cpu fans speed. So far, I > have not seen PCs which do this, but who knows? > > You can run a stress test, measuring the CPU temperature, with and > without the SMIs disabled. This way, if the SMIs are involved in > regulating the cpu fan speed, you will know it, and in this case, yes, > you can not disable them. > > Note however that the Intel chipsets allow to prevent you from disabling > the SMIs. So, it would be plain silly if your PC manufacturer used the > SMI for regulating the cpu fan speed, and did not prevent you from > disabling them. Also note that the chipset allows you to disable the SMI sources selectively, so, if the cpu fan speed regulation is a fast SMI, you can disable the others, and keep that one. So, there are several things to try before giving up on SMIs. -- Gilles.