--etb-walkback-cycles

--etb-walkback-cycles integer

Controls the number of cycles to walk back when iterating from the most recent execution trace buffer (ETB) entry to the oldest ETB entry.

Use this option to change the way in which HP Caliper picks the instruction pointer (IP) samples from the 16 IP entries in an ETB sample. When iterating from the most recent entry, HP Caliper computes the cumulative elapsed cycles by adding up each entry's bubble cycles plus one cycle per entry. When an entry is reached for which the cumulative elapsed cycles is greater than or equal to the integer specified in this option, that entry is picked as the IP sample.

For more information and an example, see “--etb-freeze-delay” (p. 59).

--event-defaults

--event-defaults [privilege-level-mask=level][:threshold=int]

Controls where and when HP Caliper measures events while your application is executing. You can use this option to set the default privilege level for all PMU events (including the sampling event).

privilege-level-mask=levelDetermines the privilege level setting for a given counter. By default, counters are measured when your application runs in user space (user) The privilege levels available are:

•user

•kernel

•all

You can abbreviate this qualifier to PLM. The qualifier is not case-sensitive.

threshold=int

An integer value that specifies how HP Caliper counts events.

 

• If the value is zero, HP Caliper counts all events.

 

• If the value is greater than zero, HP Caliper counts only

 

the CPU cycles in which the number of events is greater

 

than or equal to the value you specify.

 

The default value is zero.

Example

Assume that you want to capture samples containing the:

•Number of cycles during which three or more FP_OPS_RETIRED events occurred, while executing in kernel space

•Number of cycles during which four or more NOPS_RETIRED events occurred, in user space

•Total number of NOPS_RETIRED at all levels

In addition, assume that you want the samples to be captured every time 10,000 cycles occur, during which two or more IA64_INST_RETIRED events occur, at all privilege levels.

Use this combination of options:

caliper pmu_trace

--event-defaults PLM=all:threshold=3

--metrics FP_OPS_RETIRED:PLM=kernel,NOPS_RETIRED:PLM=user:TH=4,NOPS_RETIRED:TH=0 --sampling-spec 10000,,IA64_INST_RETIRED:TH=2

60 HP Caliper Options