To collect more accurate CPU time information, the
uses the Event Tracing for Windows* (ETW) capability. For example, without ETW, a sample is taken every 10ms. For each sample, the OS is queried for the amount of time the thread executed and the difference is calculated between the samples, resulting in the delta. The information returned by the OS via this mechanism has a coarse granularity.
totals the deltas and displays it in the user interface. However, with ETW enabled, the
can filter out any time spent executing other threads and accurately calculate time for monitored threads within each 10ms sample based on the context switch information acquired from ETW. Based on this additional information, the CPU time metric calculated for the function/thread will be more accurate.