HP Caliper User's Guide

• Hint
Percentage of all thread switches that were triggered by the “hint@pause”
instruction. This is when the measured process voluntarily gives up the processor
because it is about to wait for something (like a mutex). A non-zero value indicates
a “good” use of HyperThreading: this process has natural “idle” time that another
process can make use of.
• Other
Percentage of all other reasons that thread switches occurred.
• 0–3
Percentage of thread switches that were triggered after the processor had stalled
for 0 to 3 cycles. A large value indicates efficient HyperThreading.
• 4–15
Percentage of thread switches that were triggered after the processor had stalled
for 4 to 15 cycles. A non-zero value represents wasted processor cycles.
• 16–63
Percentage of thread switches that were triggered after the processor had stalled
for 16 to 63 cycles. A non-zero value represents wasted processor cycles.
• 64–255
Percentage of thread switches that were triggered after the processor had stalled
for 64 to 255 cycles. A non-zero value represents wasted processor cycles.
• >=256
Percentage of thread switches that were triggered after the processor had stalled
for 256 or more cycles. A non-zero value represents wasted processor cycles.
• Overhead Cycles Per Sec
Number of processor cycles per second consumed by the thread switching itself.
A large value indicates that many cycles were lost to the process in overhead.
• Gated Cycles Per Sec
Number of processor cycles per second that a pending thread switch was held up
waiting for some blocking condition to clear.
threadswitch Event Set 345