Re: [PATCH RFC V4 2/3] kvm: Note down when cpu relax intercepted or pause loop exited

2012-07-17 Thread Raghavendra K T
On 07/17/2012 01:52 PM, Avi Kivity wrote: On 07/16/2012 08:24 PM, Raghavendra K T wrote: So are you saying allow vcpu to spin in non over-commit scenarios? So that we avoid all yield_to etc... ( Or even in some other place where it is useful). When is yielding useful, if you're not

Re: [PATCH RFC V4 2/3] kvm: Note down when cpu relax intercepted or pause loop exited

2012-07-17 Thread Avi Kivity
On 07/16/2012 08:24 PM, Raghavendra K T wrote: > So are you saying allow vcpu to spin in non over-commit scenarios? So > that we avoid all yield_to etc... > > ( Or even in some other place where it is useful). When is yielding useful, if you're not overcommitted? -- error compiling

Re: [PATCH RFC V4 2/3] kvm: Note down when cpu relax intercepted or pause loop exited

2012-07-17 Thread Avi Kivity
On 07/16/2012 08:24 PM, Raghavendra K T wrote: So are you saying allow vcpu to spin in non over-commit scenarios? So that we avoid all yield_to etc... ( Or even in some other place where it is useful). When is yielding useful, if you're not overcommitted? -- error compiling committee.c:

Re: [PATCH RFC V4 2/3] kvm: Note down when cpu relax intercepted or pause loop exited

2012-07-17 Thread Raghavendra K T
On 07/17/2012 01:52 PM, Avi Kivity wrote: On 07/16/2012 08:24 PM, Raghavendra K T wrote: So are you saying allow vcpu to spin in non over-commit scenarios? So that we avoid all yield_to etc... ( Or even in some other place where it is useful). When is yielding useful, if you're not

Re: [PATCH RFC V4 2/3] kvm: Note down when cpu relax intercepted or pause loop exited

2012-07-16 Thread Raghavendra K T
On 07/16/2012 03:31 PM, Avi Kivity wrote: On 07/16/2012 11:25 AM, Raghavendra K T wrote: From: Raghavendra K T Noting pause loop exited vcpu or cpu relax intercepted helps in filtering right candidate to yield. Wrong selection of vcpu; i.e., a vcpu that just did a pl-exit or cpu relax

Re: [PATCH RFC V4 2/3] kvm: Note down when cpu relax intercepted or pause loop exited

2012-07-16 Thread Avi Kivity
On 07/16/2012 11:25 AM, Raghavendra K T wrote: > From: Raghavendra K T > > Noting pause loop exited vcpu or cpu relax intercepted helps in > filtering right candidate to yield. Wrong selection of vcpu; > i.e., a vcpu that just did a pl-exit or cpu relax intercepted may > contribute to

[PATCH RFC V4 2/3] kvm: Note down when cpu relax intercepted or pause loop exited

2012-07-16 Thread Raghavendra K T
From: Raghavendra K T Noting pause loop exited vcpu or cpu relax intercepted helps in filtering right candidate to yield. Wrong selection of vcpu; i.e., a vcpu that just did a pl-exit or cpu relax intercepted may contribute to performance degradation. Signed-off-by: Raghavendra K T --- V2 was:

[PATCH RFC V4 2/3] kvm: Note down when cpu relax intercepted or pause loop exited

2012-07-16 Thread Raghavendra K T
From: Raghavendra K T raghavendra...@linux.vnet.ibm.com Noting pause loop exited vcpu or cpu relax intercepted helps in filtering right candidate to yield. Wrong selection of vcpu; i.e., a vcpu that just did a pl-exit or cpu relax intercepted may contribute to performance degradation.

Re: [PATCH RFC V4 2/3] kvm: Note down when cpu relax intercepted or pause loop exited

2012-07-16 Thread Avi Kivity
On 07/16/2012 11:25 AM, Raghavendra K T wrote: From: Raghavendra K T raghavendra...@linux.vnet.ibm.com Noting pause loop exited vcpu or cpu relax intercepted helps in filtering right candidate to yield. Wrong selection of vcpu; i.e., a vcpu that just did a pl-exit or cpu relax intercepted

Re: [PATCH RFC V4 2/3] kvm: Note down when cpu relax intercepted or pause loop exited

2012-07-16 Thread Raghavendra K T
On 07/16/2012 03:31 PM, Avi Kivity wrote: On 07/16/2012 11:25 AM, Raghavendra K T wrote: From: Raghavendra K Traghavendra...@linux.vnet.ibm.com Noting pause loop exited vcpu or cpu relax intercepted helps in filtering right candidate to yield. Wrong selection of vcpu; i.e., a vcpu that just