[PATCH] KVM: MMU: Inform users of mmio generation wraparound

2013-06-20 Thread Takuya Yoshikawa
Without this information, users will just see unexpected performance problems and there is little chance we will get good reports from them: note that mmio generation is increased even when we just start, or stop, dirty logging for some memory slot, in which case users should never expect all

Re: [PATCH] KVM: MMU: Inform users of mmio generation wraparound

2013-06-20 Thread Paolo Bonzini
Il 20/06/2013 10:59, Takuya Yoshikawa ha scritto: Without this information, users will just see unexpected performance problems and there is little chance we will get good reports from them: note that mmio generation is increased even when we just start, or stop, dirty logging for some memory

Re: [PATCH] KVM: MMU: Inform users of mmio generation wraparound

2013-06-20 Thread Gleb Natapov
On Thu, Jun 20, 2013 at 12:59:54PM +0200, Paolo Bonzini wrote: Il 20/06/2013 10:59, Takuya Yoshikawa ha scritto: Without this information, users will just see unexpected performance problems and there is little chance we will get good reports from them: note that mmio generation is

Re: [PATCH] KVM: MMU: Inform users of mmio generation wraparound

2013-06-20 Thread Takuya Yoshikawa
On Thu, 20 Jun 2013 14:45:04 +0300 Gleb Natapov g...@redhat.com wrote: On Thu, Jun 20, 2013 at 12:59:54PM +0200, Paolo Bonzini wrote: Il 20/06/2013 10:59, Takuya Yoshikawa ha scritto: Without this information, users will just see unexpected performance problems and there is little chance

Re: [PATCH] KVM: MMU: Inform users of mmio generation wraparound

2013-06-20 Thread Paolo Bonzini
Il 20/06/2013 13:45, Gleb Natapov ha scritto: On Thu, Jun 20, 2013 at 12:59:54PM +0200, Paolo Bonzini wrote: Il 20/06/2013 10:59, Takuya Yoshikawa ha scritto: Without this information, users will just see unexpected performance problems and there is little chance we will get good reports from

Re: [PATCH] KVM: MMU: Inform users of mmio generation wraparound

2013-06-20 Thread Gleb Natapov
On Thu, Jun 20, 2013 at 02:35:36PM +0200, Paolo Bonzini wrote: Il 20/06/2013 13:45, Gleb Natapov ha scritto: On Thu, Jun 20, 2013 at 12:59:54PM +0200, Paolo Bonzini wrote: Il 20/06/2013 10:59, Takuya Yoshikawa ha scritto: Without this information, users will just see unexpected performance

Re: [PATCH] KVM: MMU: Inform users of mmio generation wraparound

2013-06-20 Thread Gleb Natapov
On Thu, Jun 20, 2013 at 09:28:37PM +0900, Takuya Yoshikawa wrote: On Thu, 20 Jun 2013 14:45:04 +0300 Gleb Natapov g...@redhat.com wrote: On Thu, Jun 20, 2013 at 12:59:54PM +0200, Paolo Bonzini wrote: Il 20/06/2013 10:59, Takuya Yoshikawa ha scritto: Without this information, users

Re: [PATCH] KVM: MMU: Inform users of mmio generation wraparound

2013-06-20 Thread Paolo Bonzini
Il 20/06/2013 14:54, Gleb Natapov ha scritto: If they see mysterious peformance problems induced by this wraparound, the only way to know the cause later is by this kind of information in the syslog. So even the first wraparound may better be printed out IMO. Think about starting hundreds

Re: [PATCH] KVM: MMU: Inform users of mmio generation wraparound

2013-06-20 Thread Takuya Yoshikawa
On Thu, 20 Jun 2013 15:54:38 +0300 Gleb Natapov g...@redhat.com wrote: On Thu, Jun 20, 2013 at 09:28:37PM +0900, Takuya Yoshikawa wrote: On Thu, 20 Jun 2013 14:45:04 +0300 Gleb Natapov g...@redhat.com wrote: On Thu, Jun 20, 2013 at 12:59:54PM +0200, Paolo Bonzini wrote: Il

Re: [PATCH] KVM: MMU: Inform users of mmio generation wraparound

2013-06-20 Thread Takuya Yoshikawa
On Thu, 20 Jun 2013 15:14:42 +0200 Paolo Bonzini pbonz...@redhat.com wrote: Il 20/06/2013 14:54, Gleb Natapov ha scritto: If they see mysterious peformance problems induced by this wraparound, the only way to know the cause later is by this kind of information in the syslog. So even the