From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: [patch 1/2] KVM: hlt emulation should take in-kernel APIC/PIT timers into account Date: Fri, 9 May 2008 11:53:00 -0300 Message-ID: <20080509145300.GA11955@dmt> References: <20080410201254.316224847@localhost.localdomain> <20080411175326.GA3800@dmt> <4801D236.6000604@qumranet.com> <200805091549.20620.sheng.yang@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel@lists.sourceforge.net, Avi Kivity To: "Yang, Sheng" Return-path: Content-Disposition: inline In-Reply-To: <200805091549.20620.sheng.yang@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces@lists.sourceforge.net Errors-To: kvm-devel-bounces@lists.sourceforge.net List-Id: kvm.vger.kernel.org On Fri, May 09, 2008 at 03:49:20PM +0800, Yang, Sheng wrote: > On Sunday 13 April 2008 17:28:22 Avi Kivity wrote: > > Marcelo Tosatti wrote: > > > On Fri, Apr 11, 2008 at 03:12:41PM +0300, Avi Kivity wrote: > > >> This breaks ia64 (and shouldn't s390 use this too?) > > >> > > >>> * We will block until either an interrupt or a signal wakes us up > > >>> */ > > >>> while (!kvm_cpu_has_interrupt(vcpu) > > >>> + && !kvm_cpu_has_pending_timer(vcpu) > > >> > > >> I guess the fix is to stub this out for the other archs. > > > > > > Agreed. How's this. > > > > Better :); applied. > > Hi, Marcelo > > This patch got into trouble when OS don't use PIT/LAPIC timer and don't > disable them. Then the pending counters would keep increasing, but the HLT > emulation can't be executed. And this would resulted in mass a lot (above > 220,000 per second) halt_exit for the Windows XP that using RTC as the > clocksource (and keep PIT enabled after bios did, just mask the pin) idle, > and the cpu utilize would be about 100% of QEmu process. > > The following patch used another way to fix the issue, though not very formal. Hi Sheng, Did you have kvm.git commit 8ae6dc90ac84d9734e343210c8ec709f50cd9d89 when testing this? I believe it should fix that issue, because "ps->inject_pending" won't be set by kvm_pit_timer_intr_post() if the IRQ is masked. Please correct me if I'm wrong. ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone