Category Archives: xperf

O(n^2) in CreateProcess

Posted on April 21, 2019 by

So many possible introductions to this one: Windows 7: Sheesh, I sure am slow at creating processes Windows 10: Hold my beer… Or how about: A) How long does CreateProcess take on Windows? B) How long would you like it … Continue reading →

Posted in Investigative Reporting, Performance, xperf | Tagged | 26 Comments

When Your Profiler Lies

Posted on December 9, 2018 by

Last week I wrote about the performance consequences of inadvertently loading gdi32.dll into processes that are created and destroyed at very high rates. This week I want to share some techniques for digging deeper into this behavior, and the odd … Continue reading →

Posted in Investigative Reporting, Performance, Programming, uiforetw, xperf | Tagged , , | 20 Comments

Making Windows Slower Part 1: File Access

Posted on April 17, 2018 by

Windows has long had a reputation for slow file operations and slow process creation. Have you ever wanted to make these operations even slower? This weeks’ blog post covers a technique you can use to make all file operations on … Continue reading →

Posted in Investigative Reporting, Performance, Programming, xperf | Tagged , , | 24 Comments

What is Windows *doing* while hogging that lock

Posted on July 27, 2017 by

Earlier this month I wrote about how Windows 10 holds a lock during too much of process destruction, which both serializes this task and causes mouse-cursor hitches and UI hangs (because the same lock is used for these UI tasks). … Continue reading →

Posted in Investigative Reporting, uiforetw, xperf | Tagged , , | 19 Comments

24-core CPU and I can’t move my mouse

Posted on July 9, 2017 by

This story begins, as they so often do, when I noticed that my machine was behaving poorly. My Windows 10 work machine has 24 cores (48 hyper-threads) and they were 50% idle. It has 64 GB of RAM and that … Continue reading →

Posted in Investigative Reporting, uiforetw, xperf | Tagged , , | 260 Comments

CPU Performance Counters on Windows

Posted on November 27, 2016 by

TL;DR – I can finally record CPU performance counters for processes on Windows. I’m mostly a Windows developer but I’ll occasionally fire up my Linux box to use the perf tool to examine CPU performance counters. Sometimes you really need … Continue reading →

Posted in xperf | Tagged , , | 7 Comments

ETW Flame Graphs Made Easy

Posted on September 5, 2016 by

A bit over three years ago I wrote about how to use flame graphs to visualize CPU Usage (Sampled) data from ETW, and a year ago I added flame graph support to UIforETW. However these techniques are clumsy and slow … Continue reading →

Posted in Performance, uiforetw, xperf | Tagged , , | 33 Comments