Cpu intensive program c

As you can imagine, that's a fairly intensive mathematical calculation. The code above is Memory Intensive.

In this case, all of the work is pushed onto the Memory because all we're doing is assignment. This won't cause explosions in memory usage, but that doesn't make it any less of an example of Memory Intensive Code. Which brings me to my next point. However, that doesn't mean the designation doesn't apply and in general, most apps that we make are going to use chunks of Memory that are not small and take CPU work that is not simple.

Depending on your computer and processor, you may instead see an instant jump of equal amounts across all your cores as it distributes the work. Sometimes it can be harder to tell whether code is Memory or CPU intensive, so let's look at a different example.

This is a combination of Memory and CPU. This is a little more confusing right? Technically the two loops require calculations as well as the assignment. Do you know where I can just download some example code which is meant to be memory intensive and cpu intensive as well? I have a third party tool which is supposed to be able to manage memory and cpu resource allocated to each. Net app running on a server. Therefore I need some sample code for testing. The content you requested has been removed.

Ask a question. Quick access. Search related threads. Remove From My Forums. Filter to include only the processes identified as part of the critical path. The resulting graph is shown in Figure 36 Critical Path Timeline:.

Figure 36 Critical Path Timeline shows that Explorer. Zoom to the time period after the previously-analyzed wait chain and perform another analysis. In this case, analysis reveals a large number of threads that are internal to Explorer. In this case, further analysis is not likely to yield actionable insights. Activities are often delayed because a thread on the critical path uses significant CPU time.

By using the thread state model, you can see that this problem is characterized by a thread on the critical path that spends an exceptional amount of time in the Running state. On some hardware, this heavy CPU usage can contribute to delays. Many assessments use heuristics to identify direct CPU usage-related problems. Significant CPU usage on the critical path is reported as an issue in the following form:. Where P is the process that is running, A is the activity, and x is the time in seconds.

If these issues are reported for an activity that incurs delays, direct CPU usage might be the cause. Zoom to an area of interest in the graph and select the Utilization by Process and Thread preset. By default, the table displays rows at the top that have the highest aggregate CPU usage. If the processes and threads that consume the most CPU correspond to any threads in the critical path, direct CPU usage is probably a factor. This example is shown in Figure 37 Thread After you discover that direct CPU usage contributes to a delay on the critical path, you must identify the specific modules and functions that contribute to the delay.

You can expand an assessment-reported direct CPU usage issue to display the critical path that is impacted by the direct CPU usage. If you expand the node that is associated with the CPU usage, the stacks that are associated with the CPU usage and associated modules will display. If the assessment did not report an issue, or if you require additional verification, you can use the CPU Usage Sampled graph to manually collect information on the modules and functions that are involved in a CPU usage issue.

To do this, you must zoom to the area of interest and view the stacks that are sorted by CPU Usage. Zoom the timeline to display only the portion of the critical path that is affected by the CPU issue. Add the Stack column to the display, and then drag this column to the right of Thread ID left of the bar. This puts the most interesting stacks on top. To extract a copy of the stack, select all the rows, right-click, and click Copy Selection.

Direct CPU usage has higher impact on computers that have lower-end processors. In these cases, you can add more processing power to the computer. Or, you might be able to remove the problem modules from the critical path or from the system. If you can change the components, consider a redesign effort to achieve one of the following results:.

CPU usage by threads that are not on the critical path and that might be unrelated to the activity , can cause threads that are on the critical path to be delayed. The thread state model shows that this problem is characterized by threads on the critical path that spend an unusual amount of time in the Ready state.

Many assessments use heuristics to identify interference-related problems. These are reported in one of the following two forms:.

Process P is starved. The starvation causes a delay to the impacted activity A of x ms. Process P is preempted. The preemption causes a delay to the impacted activity A of x ms. The first form reflects interference from threads at the same priority level as the thread on the critical path.

The second form reflects interference from threads that are at a higher priority level than the thread on the critical path. If these types of issues are reported for a delayed activity, thread interference can be the cause. Zoom to the interval and apply the Utilization by CPU preset. Apply the Utilization by Process, Thread preset and sort by the first Ready us column.

This is the column that includes the Sum aggregation. Expand the process of the activity that is affected and look at the Ready time for threads on the critical path. This value is the maximum time that the delay can be reduced by resolving any thread Interference issue.

A value with a magnitude significant relative to the delay being investigated indicates that a thread interference problem exists. After the issue is identified, you must determine why the affected thread spent so much time in the Ready state. You must first determine whether the thread is restricted to certain processors.

Although you cannot directly obtain this information, you can examine the CPU usage history of a thread during periods of high CPU utilization. This is the period when threads tend to frequently switch between processors. The value in the Cpu column reflects the number of processors on which the thread ran during the current time interval. If the value is less than the number of available processors, the thread is probably restricted to certain CPUs.

To do this, you must identify the intervals that the thread spent in the Ready state and then examine what other threads or processes were running during those intervals. Construct a graph that shows when the thread was in the Ready state and apply the Utilization by Process, Thread preset. Click OK. In this case, the thread spent significant time in the Ready state. To determine its typical priority, add an Average aggregation to the NewInPri column.

This number indicates that it is probably a background thread that never receives priority elevations. Select the relevant CPUs. Open the Advanced view and add a filter for the priority that you found earlier to filter out that thread. This scenario is shown in Figure 44 Thread Filter:. The middle graph shows the time that the thread was ready, and the bottom graph shows activity on the CPUs on which the thread was allowed to run in this case, Cpu1.

Zoom into a region where the thread was ready, but did not run, for most of the time during that interval. Threads or processes that have priorities that are equal to the target thread priority show time that the thread was starved. Threads or processes that have higher priority than the target thread priority show time that the thread was preempted.

You can calculate the total time that the thread was preempted by adding the times of all preemptive threads and actions. Figure 46 Usage by Priority When Target Thread was Ready shows that ms of the thread time were preempted, and ms of the thread time were starved. This figure is zoomed to a ms interval. To determine which threads are responsible for the preemption and starvation of this thread, add the NewProcess column to the right of the NewInPri column and review the priority levels at which processes were running.

In this case, the preemption and starvation were primarily caused by another thread in the same process and by TestResidentApp. You can assume that these processes receive periodic priority elevations above their base priority. You can resolve preemption or starvation issues by changing the configuration or components. Consider the following remedies:. Change the time when the problematic processes run; for example, delay their start time to occur when the computer reboots.

If the problem components can be changed, redesign them to be less CPU-intensive or to run at a lower priority. This situation can cause similar delays to thread interference.

When threads must complete operations at a regular high-frequency rate, such as in video playback or animation, interference by DPCs and ISRs can cause operational problems.

DPC D exceeds the threshold of m milliseconds x times during P. The n instances of this DPC run for a combined total of t milliseconds. Where D is the DPC, m is the number of milliseconds that sets the threshold, x is the number of times that the DPC exceeded the threshold, P is the current process, n is the number of instances that the DPC ran, and t is the total time in milliseconds that the DPC ran over the threshold.

DPC sdbus. SdbusWorkerDpc exceeds the goal of 3. The instances of this DPC run for a combined total of milliseconds. For additional data, zoom into the time period that occurs ms before several problem events display. Thread is in the Running state on CPU2 for Expand the stack to view the DPC activity for the process that is most related to the impacted activity, as shown in, expand the stack to understand what the DPC was doing.

Make a note of the module and function names. On the Filter tab, change the Hide rows that match the filter setting to Keep rows that match the filter. Right-click a cell in the Stack column and then click Find in this column. Check Add to current selection , and click Find All to select all instances of the function.

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