From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] Add support for HPET periodic timer. Date: Mon, 13 Aug 2007 11:04:46 +0300 Message-ID: <46C0109E.3090800@qumranet.com> References: <11867779422209-git-send-email-kronos.it@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, qemu-devel-qX2TKyscuCcdnm+yROfE0A@public.gmane.org To: Luca Tettamanti Return-path: In-Reply-To: <11867779422209-git-send-email-kronos.it-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org Luca Tettamanti wrote: > Linux operates the HPET timer in legacy replacement mode, which means that the > periodic interrupt of the CMOS RTC is not delivered (qemu won't be able to use > /dev/rtc). Add support for HPET (/dev/hpet) as a replacement for the RTC; the > periodic interrupt is delivered via SIGIO and is handled in the same way as the > RTC timer. > HPET must be explicitly enabled with -use-hpet. > > Are there any downsides to using HPET? If not, I suggest making it the default, in order to reduce complexity for the user. Something like: - try to use HPET (unless -no-rtc selected) - try to use RTC (unless -no-rtc selected) - fallback to normal unix facilities -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1IKUuk-0002WD-J1 for qemu-devel@nongnu.org; Mon, 13 Aug 2007 04:04:38 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1IKUuj-0002VI-Uf for qemu-devel@nongnu.org; Mon, 13 Aug 2007 04:04:38 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1IKUuj-0002V8-R6 for qemu-devel@nongnu.org; Mon, 13 Aug 2007 04:04:37 -0400 Received: from il.qumranet.com ([82.166.9.18]) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1IKUui-0000Mt-U5 for qemu-devel@nongnu.org; Mon, 13 Aug 2007 04:04:37 -0400 Message-ID: <46C0109E.3090800@qumranet.com> Date: Mon, 13 Aug 2007 11:04:46 +0300 From: Avi Kivity MIME-Version: 1.0 References: <11867779422209-git-send-email-kronos.it@gmail.com> In-Reply-To: <11867779422209-git-send-email-kronos.it@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Re: [kvm-devel] [PATCH] Add support for HPET periodic timer. Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Luca Tettamanti Cc: kvm-devel@lists.sourceforge.net, qemu-devel@nongnu.org Luca Tettamanti wrote: > Linux operates the HPET timer in legacy replacement mode, which means that the > periodic interrupt of the CMOS RTC is not delivered (qemu won't be able to use > /dev/rtc). Add support for HPET (/dev/hpet) as a replacement for the RTC; the > periodic interrupt is delivered via SIGIO and is handled in the same way as the > RTC timer. > HPET must be explicitly enabled with -use-hpet. > > Are there any downsides to using HPET? If not, I suggest making it the default, in order to reduce complexity for the user. Something like: - try to use HPET (unless -no-rtc selected) - try to use RTC (unless -no-rtc selected) - fallback to normal unix facilities -- error compiling committee.c: too many arguments to function