From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1LN9dm-0006bQ-Sk for qemu-devel@nongnu.org; Wed, 14 Jan 2009 12:34:54 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1LN9dk-0006Z2-Po for qemu-devel@nongnu.org; Wed, 14 Jan 2009 12:34:54 -0500 Received: from [199.232.76.173] (port=43443 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LN9dk-0006YU-91 for qemu-devel@nongnu.org; Wed, 14 Jan 2009 12:34:52 -0500 Received: from mx2.redhat.com ([66.187.237.31]:43434) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1LN9dj-0004uI-Ka for qemu-devel@nongnu.org; Wed, 14 Jan 2009 12:34:51 -0500 Received: from int-mx2.corp.redhat.com (int-mx2.corp.redhat.com [172.16.27.26]) by mx2.redhat.com (8.13.8/8.13.8) with ESMTP id n0EHYonj028271 for ; Wed, 14 Jan 2009 12:34:50 -0500 Message-ID: <496E2238.5050309@redhat.com> Date: Wed, 14 Jan 2009 19:34:48 +0200 From: Avi Kivity MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH][RESEND] Time drift again. References: <20090114115910.GR3267@redhat.com> <20090114170222.GE6431@shareable.org> In-Reply-To: <20090114170222.GE6431@shareable.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Jamie Lokier wrote: > Gleb Natapov wrote: > >> After my last patch to fix interrupt coalescing was rejected >> on the basis that it is too intrusive we decided to make the >> fix much more localized and only fix the problem for RTC time >> source. Unfortunately it is impossible to fix the problem entirely >> inside RTC code like Andrzej proposed since Windows reads RTC >> register C more then once on each time interrupt so it is impossible >> to count reliably how many interrupt windows actually handled. >> Proposed solution is localized to I386 target and is disabled by >> default. To enable it "-rtc-td-hack" flag should be used. >> > > I truly don't understand why the time correction is done by arcane > guest-specific details like counting register reads, making interrupts > behave different from real hardware, and only correcting guests which > use particular clock sources - instead of simply warping virtual time > (in all the places it's used) which might actually work on all targets > and all guest OSes. > > I don't remember anybody responding to that suggestion. > Was it a silly one? > Maybe it's silly, but I don't even understand it. What do you mean by "warping virtual time"? I have a hard time with these words even when used singly. -- error compiling committee.c: too many arguments to function