We also hacked the source like the patch. But the issue is not caused by it. We are still trying to figure the reason out. Thanks! Xiantao -----Original Message----- From: Gleb Natapov [mailto:gleb@xxxxxxxxxx] Sent: Thursday, March 12, 2009 7:04 PM To: Zhang, Xiantao Cc: Avi Kivity; Marcelo Tosatti; Ingo Molnar; kvm@xxxxxxxxxxxxxxx; Peter Zijlstra Subject: Re: x86: use smp_send_reschedule in kvm_vcpu_kick On Thu, Mar 12, 2009 at 10:31:47AM +0800, Zhang, Xiantao wrote: > Avi Kivity wrote: > > Marcelo Tosatti wrote: > >> OK, reworked patch: > >> - change ia64 in addition to x86 > >> - add comment on smp send reschedule handlers about KVM's usage > >> > >> Untested on IA64. > >> > >> KVM: use smp_send_reschedule in kvm_vcpu_kick > >> > >> KVM uses a function call IPI to cause the exit of a guest running on > >> a physical cpu. For virtual interrupt notification there is no need > >> to wait on IPI receival, or to execute any function. > >> > >> This is exactly what the reschedule IPI does, without the overhead > >> of function IPI. So use it instead of smp_call_function_single in > >> kvm_vcpu_kick. > >> > >> Also change the "guest_mode" variable to a bit in vcpu->requests, and > >> use that to collapse multiple IPI's that would be issued between the > >> first one and zeroing of guest mode. > >> > >> This allows kvm_vcpu_kick to called with interrupts disabled. > >> > > > > Looks good. Will wait for Xiantao's test-n-ack before applying. > > kvm-ia64 is broken due to recent check-ins about irq-bits, and we are trying to fix it. For this patch, ia64 has to export the symbol smp_send_reschedule before applying the patch. Can you try this patch please: http://patchwork.kernel.org/patch/11103/ -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
