lid sleep enabled due to unsafe cpu insomniax

Lid sleep enabled due to unsafe cpu insomniax how to#
Lid sleep enabled due to unsafe cpu insomniax windows 8#

Our internal trace recording tool has an optional input event logger which puts all keyboard and mouse input into the trace (watch for it).

Look for patterns in the CPU usage or other data.

Use instrumentation in the functions of interest.

Find the key stroke that triggered the hang, through logging of input events.

A trace might cover 60 seconds, and a hang might last for 2 seconds or less, so knowing where to look is crucial. It is sufficiently simple and self-contained that I can cover it end-to-end in a single (long) post.įinding the hang When profiling a transient problem such as a frame-rate glitch or a temporary hang the first challenge is to locate the hang in the trace. The last investigation is the one I want to cover today.

Finding the cause of (and a workaround for) repeated 2-6 second hangs in Visual Studio's output window.

Finding the chain of lock contention that caused frame rate hitches on a heavily loaded system.

Finding the cause of frame rate hitches during fraps recording.

Finding the cause of a 10x perf-reduction when upgrading to a newer version of Windows.

Profiling Luke Stackwalker to find out why it caused frame rate glitches in the game it was profiling.

Finding the cause of brief startup hangs in Internet Explorer and various games.

All were difficult or impossible to analyze through CPU sampling or other 'normal' CPU profilers.

Some of these delays were short enough to be difficult to notice, yet long enough to matter. I've had good luck using Wait Analysis to find many performance problems.

Lid sleep enabled due to unsafe cpu insomniax windows 8#

The rest of this post assumes that you have installed xperf (preferably the Windows 8 version) and have familiarity with at least Xperf Analysis Basics.

Lid sleep enabled due to unsafe cpu insomniax how to#

Xperf Analysis Basics – the essential knowledge of how to navigate the xperf UI, including how to set up symbol paths.Xperf Basics: Recording a Trace – this covers installing xperf (takes just a few minutes), recording traces, and adding ETW events to your game.The entire series can be found here, but the most important ones are: Therefore I highly recommend that you start by reading some previous articles from this series. In short, lots of profilers can tell you what your program is doing, but few profilers are excellent at telling you why your program is doing nothing.

While I think xperf is a better sampling profiler than most of the alternatives (higher frequency, lower overhead, kernel and user mode), xperf is really at its best when it reveals information that other profilers cannot measure at all. In the past I've talked about using xperf to identify slowdowns in PowerPoint by using xperf's built-in sampling profiler, but that actually understates the true value of Xperf. The Windows Performance Toolkit, also known as xperf, is a powerful (and free!) system-wide Windows profiler.