| Message ID | 1669310088-13482-6-git-send-email-renyu.zj@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add metrics for neoverse-n2 | expand |
On Thu, Nov 24, 2022 at 9:15 AM Jing Zhang <renyu.zj@linux.alibaba.com> wrote: > > Add PE utilization related metrics. > > Signed-off-by: Jing Zhang <renyu.zj@linux.alibaba.com> > --- > .../arch/arm64/arm/neoverse-n2/metrics.json | 45 ++++++++++++++++++++++ > 1 file changed, 45 insertions(+) > > diff --git a/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json b/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json > index 23c7d62..7b54819 100644 > --- a/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json > +++ b/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json > @@ -189,5 +189,50 @@ > "MetricGroup": "Branch", > "MetricName": "branch_miss_pred_rate", > "ScaleUnit": "100%" > + }, > + { > + "MetricExpr": "instructions / CPU_CYCLES", > + "PublicDescription": "The average number of instructions executed for each cycle.", > + "BriefDescription": "Instructions per cycle", > + "MetricGroup": "PEutilization", > + "MetricName": "ipc" > + }, A related useful metric is percentage of peak, so if the peak IPC is 8 (usually a constant related to the number of functional units) then you can just compute the ratio of IPC with this. > + { > + "MetricExpr": "INST_RETIRED / CPU_CYCLES", > + "PublicDescription": "Architecturally executed Instructions Per Cycle (IPC)", > + "BriefDescription": "Architecturally executed Instructions Per Cycle (IPC)", The duplicated descriptions are unnecessary. Drop the public one for consistency with what we do for Intel: https://github.com/intel/perfmon/blob/main/scripts/create_perf_json.py#L299 > + "MetricGroup": "PEutilization", > + "MetricName": "retired_ipc" > + }, > + { > + "MetricExpr": "INST_SPEC / CPU_CYCLES", > + "PublicDescription": "Speculatively executed Instructions Per Cycle (IPC)", > + "BriefDescription": "Speculatively executed Instructions Per Cycle (IPC)", > + "MetricGroup": "PEutilization", > + "MetricName": "spec_ipc" > + }, > + { > + "MetricExpr": "OP_RETIRED / OP_SPEC", > + "PublicDescription": "Fraction of operations retired", > + "BriefDescription": "Fraction of operations retired", Would instructions be clearer than operations here? > + "MetricGroup": "PEutilization", > + "MetricName": "retired_rate", > + "ScaleUnit": "100%" > + }, > + { > + "MetricExpr": "1 - OP_RETIRED / OP_SPEC", Should OP_RETIRED be greater than OP_SPEC? In which case won't this metric be negative? > + "PublicDescription": "Fraction of operations wasted", > + "BriefDescription": "Fraction of operations wasted", > + "MetricGroup": "PEutilization", > + "MetricName": "wasted_rate", > + "ScaleUnit": "100%" > + }, > + { > + "MetricExpr": "OP_RETIRED / OP_SPEC * (1 - (STALL_SLOT - CPU_CYCLES) / (CPU_CYCLES * 5))", > + "PublicDescription": "Utilization of CPU", > + "BriefDescription": "Utilization of CPU", Some more detail in the description would be useful. > + "MetricGroup": "PEutilization", > + "MetricName": "cpu_utilization", > + "ScaleUnit": "100%" > } > ] > -- > 1.8.3.1 >
在 2022/12/1 上午2:58, Ian Rogers 写道: > On Thu, Nov 24, 2022 at 9:15 AM Jing Zhang <renyu.zj@linux.alibaba.com> wrote: >> >> Add PE utilization related metrics. >> >> Signed-off-by: Jing Zhang <renyu.zj@linux.alibaba.com> >> --- >> .../arch/arm64/arm/neoverse-n2/metrics.json | 45 ++++++++++++++++++++++ >> 1 file changed, 45 insertions(+) >> >> diff --git a/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json b/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json >> index 23c7d62..7b54819 100644 >> --- a/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json >> +++ b/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json >> @@ -189,5 +189,50 @@ >> "MetricGroup": "Branch", >> "MetricName": "branch_miss_pred_rate", >> "ScaleUnit": "100%" >> + }, >> + { >> + "MetricExpr": "instructions / CPU_CYCLES", >> + "PublicDescription": "The average number of instructions executed for each cycle.", >> + "BriefDescription": "Instructions per cycle", >> + "MetricGroup": "PEutilization", >> + "MetricName": "ipc" >> + }, > > A related useful metric is percentage of peak, so if the peak IPC is 8 > (usually a constant related to the number of functional units) then > you can just compute the ratio of IPC with this. > Glad to discuss these with you. The peak ipc value of neoverse-n2 is 5. Maybe I should add an ipc_rate metric? >> + { >> + "MetricExpr": "INST_RETIRED / CPU_CYCLES", >> + "PublicDescription": "Architecturally executed Instructions Per Cycle (IPC)", >> + "BriefDescription": "Architecturally executed Instructions Per Cycle (IPC)", > > > The duplicated descriptions are unnecessary. Drop the public one for > consistency with what we do for Intel: > https://github.com/intel/perfmon/blob/main/scripts/create_perf_json.py#L299 > Sounds good, will do. >> + "MetricGroup": "PEutilization", >> + "MetricName": "retired_ipc" >> + }, >> + { >> + "MetricExpr": "INST_SPEC / CPU_CYCLES", >> + "PublicDescription": "Speculatively executed Instructions Per Cycle (IPC)", >> + "BriefDescription": "Speculatively executed Instructions Per Cycle (IPC)", >> + "MetricGroup": "PEutilization", >> + "MetricName": "spec_ipc" >> + }, >> + { >> + "MetricExpr": "OP_RETIRED / OP_SPEC", >> + "PublicDescription": "Fraction of operations retired", >> + "BriefDescription": "Fraction of operations retired", > > Would instructions be clearer than operations here? > operation and instruction are different. OP_RETIRED counts any operation (not instruction) that has been architecturally executed, For example, speculatively executed operations that have been abandoned for a branch mispredict will not be counted. So I think operation might be more accurate. >> + "MetricGroup": "PEutilization", >> + "MetricName": "retired_rate", >> + "ScaleUnit": "100%" >> + }, >> + { >> + "MetricExpr": "1 - OP_RETIRED / OP_SPEC", > > Should OP_RETIRED be greater than OP_SPEC? In which case won't this > metric be negative? > OP_RETIRED will not be greater than OP_SPEC. OP_SPEC counts any operation that has been speculatively executed. OP_SPEC is a superset of the OP_RETIRED event. There is a description about OP_SPEC and OP_RETIRED in this neoverse-n2 document. Link: https://documentation-service.arm.com/static/62cfe21e31ea212bb6627393?token= >> + "PublicDescription": "Fraction of operations wasted", >> + "BriefDescription": "Fraction of operations wasted", >> + "MetricGroup": "PEutilization", >> + "MetricName": "wasted_rate", >> + "ScaleUnit": "100%" >> + }, >> + { >> + "MetricExpr": "OP_RETIRED / OP_SPEC * (1 - (STALL_SLOT - CPU_CYCLES) / (CPU_CYCLES * 5))", >> + "PublicDescription": "Utilization of CPU", >> + "BriefDescription": "Utilization of CPU", > > Some more detail in the description would be useful. > Ok, I'll describe it in more detail. CPU_utilization reflects the truly effective ratio of operation executed by the CPU, which means that misprediction and stall are not included. Note that stall_slot minus cpu_cycles is a correction to the stall_slot error count. >> + "MetricGroup": "PEutilization", >> + "MetricName": "cpu_utilization", >> + "ScaleUnit": "100%" >> } >> ] >> -- >> 1.8.3.1 >>
On Thu, Dec 1, 2022 at 3:08 AM Jing Zhang <renyu.zj@linux.alibaba.com> wrote: > > > > 在 2022/12/1 上午2:58, Ian Rogers 写道: > > On Thu, Nov 24, 2022 at 9:15 AM Jing Zhang <renyu.zj@linux.alibaba.com> wrote: > >> > >> Add PE utilization related metrics. > >> > >> Signed-off-by: Jing Zhang <renyu.zj@linux.alibaba.com> > >> --- > >> .../arch/arm64/arm/neoverse-n2/metrics.json | 45 ++++++++++++++++++++++ > >> 1 file changed, 45 insertions(+) > >> > >> diff --git a/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json b/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json > >> index 23c7d62..7b54819 100644 > >> --- a/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json > >> +++ b/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json > >> @@ -189,5 +189,50 @@ > >> "MetricGroup": "Branch", > >> "MetricName": "branch_miss_pred_rate", > >> "ScaleUnit": "100%" > >> + }, > >> + { > >> + "MetricExpr": "instructions / CPU_CYCLES", > >> + "PublicDescription": "The average number of instructions executed for each cycle.", > >> + "BriefDescription": "Instructions per cycle", > >> + "MetricGroup": "PEutilization", > >> + "MetricName": "ipc" > >> + }, > > > > A related useful metric is percentage of peak, so if the peak IPC is 8 > > (usually a constant related to the number of functional units) then > > you can just compute the ratio of IPC with this. > > > > Glad to discuss these with you. > The peak ipc value of neoverse-n2 is 5. Maybe I should add an ipc_rate metric? > > >> + { > >> + "MetricExpr": "INST_RETIRED / CPU_CYCLES", > >> + "PublicDescription": "Architecturally executed Instructions Per Cycle (IPC)", > >> + "BriefDescription": "Architecturally executed Instructions Per Cycle (IPC)", > > > > > > The duplicated descriptions are unnecessary. Drop the public one for > > consistency with what we do for Intel: > > https://github.com/intel/perfmon/blob/main/scripts/create_perf_json.py#L299 > > > > Sounds good, will do. > > >> + "MetricGroup": "PEutilization", > >> + "MetricName": "retired_ipc" > >> + }, > >> + { > >> + "MetricExpr": "INST_SPEC / CPU_CYCLES", > >> + "PublicDescription": "Speculatively executed Instructions Per Cycle (IPC)", > >> + "BriefDescription": "Speculatively executed Instructions Per Cycle (IPC)", > >> + "MetricGroup": "PEutilization", > >> + "MetricName": "spec_ipc" > >> + }, > >> + { > >> + "MetricExpr": "OP_RETIRED / OP_SPEC", > >> + "PublicDescription": "Fraction of operations retired", > >> + "BriefDescription": "Fraction of operations retired", > > > > Would instructions be clearer than operations here? > > > > operation and instruction are different. OP_RETIRED counts any operation (not instruction) > that has been architecturally executed, For example, speculatively executed operations that > have been abandoned for a branch mispredict will not be counted. So I think operation might > be more accurate. Thanks, I see this note in the N2 PMU guide: """ For PMU event definitions, some events specifically count instructions, while other events count micro-operations (which are referred to as operations). Please be aware of the use of the word "operations" or "instructions" in the event description. """ From your explanation I wasn't sure if operation was a superset of instruction that included both retired and speculated ones, or whether operation had another meaning. I don't see operation being used in the micro-operation sense elsewhere in the ARM perf json, I think micro-operation is more consistent and also clearer: https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/tree/tools/perf/pmu-events/arch/arm64/arm/cortex-a75/pipeline.json?h=perf/core#n27 Perhaps the description can be something like: Of all the micro-operations issued, what percentage were retired. A lower number indicates bad speculation. An alternate way to add documentation is the perf wiki's glossary: https://perf.wiki.kernel.org/index.php/Glossary I added the Neoverse N2 PMU Guide to: https://perf.wiki.kernel.org/index.php/Useful_Links#Manuals Thanks, Ian > >> + "MetricGroup": "PEutilization", > >> + "MetricName": "retired_rate", > >> + "ScaleUnit": "100%" > >> + }, > >> + { > >> + "MetricExpr": "1 - OP_RETIRED / OP_SPEC", > > > > Should OP_RETIRED be greater than OP_SPEC? In which case won't this > > metric be negative? > > > > OP_RETIRED will not be greater than OP_SPEC. OP_SPEC counts any operation that has been > speculatively executed. OP_SPEC is a superset of the OP_RETIRED event. There is a > description about OP_SPEC and OP_RETIRED in this neoverse-n2 document. > Link: https://documentation-service.arm.com/static/62cfe21e31ea212bb6627393?token= > > >> + "PublicDescription": "Fraction of operations wasted", > >> + "BriefDescription": "Fraction of operations wasted", > >> + "MetricGroup": "PEutilization", > >> + "MetricName": "wasted_rate", > >> + "ScaleUnit": "100%" > >> + }, > >> + { > >> + "MetricExpr": "OP_RETIRED / OP_SPEC * (1 - (STALL_SLOT - CPU_CYCLES) / (CPU_CYCLES * 5))", > >> + "PublicDescription": "Utilization of CPU", > >> + "BriefDescription": "Utilization of CPU", > > > > Some more detail in the description would be useful. > > > > Ok, I'll describe it in more detail. CPU_utilization reflects the truly effective ratio of operation > executed by the CPU, which means that misprediction and stall are not included. Note that stall_slot > minus cpu_cycles is a correction to the stall_slot error count. > > >> + "MetricGroup": "PEutilization", > >> + "MetricName": "cpu_utilization", > >> + "ScaleUnit": "100%" > >> } > >> ] > >> -- > >> 1.8.3.1 > >>
在 2022/12/3 上午4:05, Ian Rogers 写道: > On Thu, Dec 1, 2022 at 3:08 AM Jing Zhang <renyu.zj@linux.alibaba.com> wrote: >> >> >> >> 在 2022/12/1 上午2:58, Ian Rogers 写道: >>> On Thu, Nov 24, 2022 at 9:15 AM Jing Zhang <renyu.zj@linux.alibaba.com> wrote: >>>> >>>> Add PE utilization related metrics. >>>> >>>> Signed-off-by: Jing Zhang <renyu.zj@linux.alibaba.com> >>>> --- >>>> .../arch/arm64/arm/neoverse-n2/metrics.json | 45 ++++++++++++++++++++++ >>>> 1 file changed, 45 insertions(+) >>>> >>>> diff --git a/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json b/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json >>>> index 23c7d62..7b54819 100644 >>>> --- a/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json >>>> +++ b/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json >>>> @@ -189,5 +189,50 @@ >>>> "MetricGroup": "Branch", >>>> "MetricName": "branch_miss_pred_rate", >>>> "ScaleUnit": "100%" >>>> + }, >>>> + { >>>> + "MetricExpr": "instructions / CPU_CYCLES", >>>> + "PublicDescription": "The average number of instructions executed for each cycle.", >>>> + "BriefDescription": "Instructions per cycle", >>>> + "MetricGroup": "PEutilization", >>>> + "MetricName": "ipc" >>>> + }, >>> >>> A related useful metric is percentage of peak, so if the peak IPC is 8 >>> (usually a constant related to the number of functional units) then >>> you can just compute the ratio of IPC with this. >>> >> >> Glad to discuss these with you. >> The peak ipc value of neoverse-n2 is 5. Maybe I should add an ipc_rate metric? >> >>>> + { >>>> + "MetricExpr": "INST_RETIRED / CPU_CYCLES", >>>> + "PublicDescription": "Architecturally executed Instructions Per Cycle (IPC)", >>>> + "BriefDescription": "Architecturally executed Instructions Per Cycle (IPC)", >>> >>> >>> The duplicated descriptions are unnecessary. Drop the public one for >>> consistency with what we do for Intel: >>> https://github.com/intel/perfmon/blob/main/scripts/create_perf_json.py#L299 >>> >> >> Sounds good, will do. >> >>>> + "MetricGroup": "PEutilization", >>>> + "MetricName": "retired_ipc" >>>> + }, >>>> + { >>>> + "MetricExpr": "INST_SPEC / CPU_CYCLES", >>>> + "PublicDescription": "Speculatively executed Instructions Per Cycle (IPC)", >>>> + "BriefDescription": "Speculatively executed Instructions Per Cycle (IPC)", >>>> + "MetricGroup": "PEutilization", >>>> + "MetricName": "spec_ipc" >>>> + }, >>>> + { >>>> + "MetricExpr": "OP_RETIRED / OP_SPEC", >>>> + "PublicDescription": "Fraction of operations retired", >>>> + "BriefDescription": "Fraction of operations retired", >>> >>> Would instructions be clearer than operations here? >>> >> >> operation and instruction are different. OP_RETIRED counts any operation (not instruction) >> that has been architecturally executed, For example, speculatively executed operations that >> have been abandoned for a branch mispredict will not be counted. So I think operation might >> be more accurate. > > Thanks, I see this note in the N2 PMU guide: > > """ > For PMU event definitions, some events specifically count > instructions, while other events count micro-operations (which are > referred to as operations). Please be aware of the use of the word > "operations" or "instructions" in the event description. > """ > > From your explanation I wasn't sure if operation was a superset of > instruction that included both retired and speculated ones, or whether > operation had another meaning. I don't see operation being used in the > micro-operation sense elsewhere in the ARM perf json, I think > micro-operation is more consistent and also clearer: > https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/tree/tools/perf/pmu-events/arch/arm64/arm/cortex-a75/pipeline.json?h=perf/core#n27 > > Perhaps the description can be something like: > Of all the micro-operations issued, what percentage were retired. A > lower number indicates bad speculation. > > An alternate way to add documentation is the perf wiki's glossary: > https://perf.wiki.kernel.org/index.php/Glossary > > I added the Neoverse N2 PMU Guide to: > https://perf.wiki.kernel.org/index.php/Useful_Links#Manuals > Thanks. The operation here is micro-operation, perhaps it is more accurate to change it to micro-operation. Description of op_retired and op_spec: https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/tree/tools/perf/pmu-events/arch/arm64/common-and-microarch.json?h=perf/core#n315 The event of op_retired counts Micro-operation architecturally executed. The counter counts each operation counted by OP_SPEC that would be executed in a simple sequential execution of the program. The event of op_spec counts Micro-operation speculatively executed. The counter counts the number of operations executed by the processing element, including those that are executed speculatively and would not be executed in a simple sequential execution of the program. So "op_retired/op_spec" is indeed "of all the micro-operations issued, what percentage were retired". But not "a lower number indicates bad speculation". I think "retired" here means "committed". In the N2 PMU guide: """ If the branch is mispredicted, and the instructions are speculatively executed, they will not be considered architecturally executed. The Arm® Architecture Reference Manual also refers to architecturally executed instructions as “retired” or “committed”. Speculatively executed instructions that are not architecturally executed will be abandoned; that is, their results will be discarded and not counted as part of the program flow. """ > >>>> + "MetricGroup": "PEutilization", >>>> + "MetricName": "retired_rate", >>>> + "ScaleUnit": "100%" >>>> + }, >>>> + { >>>> + "MetricExpr": "1 - OP_RETIRED / OP_SPEC", >>> >>> Should OP_RETIRED be greater than OP_SPEC? In which case won't this >>> metric be negative? >>> >> >> OP_RETIRED will not be greater than OP_SPEC. OP_SPEC counts any operation that has been >> speculatively executed. OP_SPEC is a superset of the OP_RETIRED event. There is a >> description about OP_SPEC and OP_RETIRED in this neoverse-n2 document. >> Link: https://documentation-service.arm.com/static/62cfe21e31ea212bb6627393?token= >> >>>> + "PublicDescription": "Fraction of operations wasted", >>>> + "BriefDescription": "Fraction of operations wasted", >>>> + "MetricGroup": "PEutilization", >>>> + "MetricName": "wasted_rate", >>>> + "ScaleUnit": "100%" >>>> + }, >>>> + { >>>> + "MetricExpr": "OP_RETIRED / OP_SPEC * (1 - (STALL_SLOT - CPU_CYCLES) / (CPU_CYCLES * 5))", >>>> + "PublicDescription": "Utilization of CPU", >>>> + "BriefDescription": "Utilization of CPU", >>> >>> Some more detail in the description would be useful. >>> >> >> Ok, I'll describe it in more detail. CPU_utilization reflects the truly effective ratio of operation >> executed by the CPU, which means that misprediction and stall are not included. Note that stall_slot >> minus cpu_cycles is a correction to the stall_slot error count. >> >>>> + "MetricGroup": "PEutilization", >>>> + "MetricName": "cpu_utilization", >>>> + "ScaleUnit": "100%" >>>> } >>>> ] >>>> -- >>>> 1.8.3.1 >>>>
diff --git a/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json b/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json index 23c7d62..7b54819 100644 --- a/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json +++ b/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json @@ -189,5 +189,50 @@ "MetricGroup": "Branch", "MetricName": "branch_miss_pred_rate", "ScaleUnit": "100%" + }, + { + "MetricExpr": "instructions / CPU_CYCLES", + "PublicDescription": "The average number of instructions executed for each cycle.", + "BriefDescription": "Instructions per cycle", + "MetricGroup": "PEutilization", + "MetricName": "ipc" + }, + { + "MetricExpr": "INST_RETIRED / CPU_CYCLES", + "PublicDescription": "Architecturally executed Instructions Per Cycle (IPC)", + "BriefDescription": "Architecturally executed Instructions Per Cycle (IPC)", + "MetricGroup": "PEutilization", + "MetricName": "retired_ipc" + }, + { + "MetricExpr": "INST_SPEC / CPU_CYCLES", + "PublicDescription": "Speculatively executed Instructions Per Cycle (IPC)", + "BriefDescription": "Speculatively executed Instructions Per Cycle (IPC)", + "MetricGroup": "PEutilization", + "MetricName": "spec_ipc" + }, + { + "MetricExpr": "OP_RETIRED / OP_SPEC", + "PublicDescription": "Fraction of operations retired", + "BriefDescription": "Fraction of operations retired", + "MetricGroup": "PEutilization", + "MetricName": "retired_rate", + "ScaleUnit": "100%" + }, + { + "MetricExpr": "1 - OP_RETIRED / OP_SPEC", + "PublicDescription": "Fraction of operations wasted", + "BriefDescription": "Fraction of operations wasted", + "MetricGroup": "PEutilization", + "MetricName": "wasted_rate", + "ScaleUnit": "100%" + }, + { + "MetricExpr": "OP_RETIRED / OP_SPEC * (1 - (STALL_SLOT - CPU_CYCLES) / (CPU_CYCLES * 5))", + "PublicDescription": "Utilization of CPU", + "BriefDescription": "Utilization of CPU", + "MetricGroup": "PEutilization", + "MetricName": "cpu_utilization", + "ScaleUnit": "100%" } ]
Add PE utilization related metrics. Signed-off-by: Jing Zhang <renyu.zj@linux.alibaba.com> --- .../arch/arm64/arm/neoverse-n2/metrics.json | 45 ++++++++++++++++++++++ 1 file changed, 45 insertions(+)