RE: [PATCH 0/3]measure SMI cost

2017-03-31 Thread Liang, Kan
> On Thu, Mar 23, 2017 at 11:25 AM, wrote: > > From: Kan Liang > > > > Currently, there is no way to measure the time cost in System > > management mode (SMM) by perf. > > > > Intel perfmon supports FREEZE_WHILE_SMM bit in IA32_DEBUGCTL. Once > it > >

RE: [PATCH 0/3]measure SMI cost

2017-03-31 Thread Liang, Kan
> On Thu, Mar 23, 2017 at 11:25 AM, wrote: > > From: Kan Liang > > > > Currently, there is no way to measure the time cost in System > > management mode (SMM) by perf. > > > > Intel perfmon supports FREEZE_WHILE_SMM bit in IA32_DEBUGCTL. Once > it > > sets, the PMU core counters will freeze

Re: [PATCH 0/3]measure SMI cost

2017-03-31 Thread Stephane Eranian
On Thu, Mar 23, 2017 at 11:25 AM, wrote: > From: Kan Liang > > Currently, there is no way to measure the time cost in System management > mode (SMM) by perf. > > Intel perfmon supports FREEZE_WHILE_SMM bit in IA32_DEBUGCTL. Once it sets, > the PMU core

Re: [PATCH 0/3]measure SMI cost

2017-03-31 Thread Stephane Eranian
On Thu, Mar 23, 2017 at 11:25 AM, wrote: > From: Kan Liang > > Currently, there is no way to measure the time cost in System management > mode (SMM) by perf. > > Intel perfmon supports FREEZE_WHILE_SMM bit in IA32_DEBUGCTL. Once it sets, > the PMU core counters will freeze on SMI handler. But

RE: [PATCH 0/3]measure SMI cost

2017-03-24 Thread Liang, Kan
> > > > > A new --smi-cost mode in perf stat is implemented to measure the > > > > SMI cost by calculating cycles and aperf results. In practice, the > > > > percentages of SMI cycles should be more useful than absolute value. > > > > > > That's only true for performance oriented analysis, but

RE: [PATCH 0/3]measure SMI cost

2017-03-24 Thread Liang, Kan
> > > > > A new --smi-cost mode in perf stat is implemented to measure the > > > > SMI cost by calculating cycles and aperf results. In practice, the > > > > percentages of SMI cycles should be more useful than absolute value. > > > > > > That's only true for performance oriented analysis, but

Re: [PATCH 0/3]measure SMI cost

2017-03-24 Thread Thomas Gleixner
On Fri, 24 Mar 2017, Andi Kleen wrote: > > > A new --smi-cost mode in perf stat is implemented to measure the SMI cost > > > by calculating cycles and aperf results. In practice, the percentages of > > > SMI cycles should be more useful than absolute value. > > > > That's only true for

Re: [PATCH 0/3]measure SMI cost

2017-03-24 Thread Thomas Gleixner
On Fri, 24 Mar 2017, Andi Kleen wrote: > > > A new --smi-cost mode in perf stat is implemented to measure the SMI cost > > > by calculating cycles and aperf results. In practice, the percentages of > > > SMI cycles should be more useful than absolute value. > > > > That's only true for

Re: [PATCH 0/3]measure SMI cost

2017-03-24 Thread Andi Kleen
> > A new --smi-cost mode in perf stat is implemented to measure the SMI cost > > by calculating cycles and aperf results. In practice, the percentages of > > SMI cycles should be more useful than absolute value. > > That's only true for performance oriented analysis, but for analyzing the > root

Re: [PATCH 0/3]measure SMI cost

2017-03-24 Thread Andi Kleen
> > A new --smi-cost mode in perf stat is implemented to measure the SMI cost > > by calculating cycles and aperf results. In practice, the percentages of > > SMI cycles should be more useful than absolute value. > > That's only true for performance oriented analysis, but for analyzing the > root

Re: [PATCH 0/3]measure SMI cost

2017-03-24 Thread Thomas Gleixner
On Thu, 23 Mar 2017, kan.li...@intel.com wrote: > From: Kan Liang > > Currently, there is no way to measure the time cost in System management > mode (SMM) by perf. > > Intel perfmon supports FREEZE_WHILE_SMM bit in IA32_DEBUGCTL. Once it sets, > the PMU core counters will

Re: [PATCH 0/3]measure SMI cost

2017-03-24 Thread Thomas Gleixner
On Thu, 23 Mar 2017, kan.li...@intel.com wrote: > From: Kan Liang > > Currently, there is no way to measure the time cost in System management > mode (SMM) by perf. > > Intel perfmon supports FREEZE_WHILE_SMM bit in IA32_DEBUGCTL. Once it sets, > the PMU core counters will freeze on SMI