Category Archives: Investigative Reporting

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 , , | 19 Comments

A Not-Called Function Can Cause a 5X Slowdown

Posted on December 3, 2018 by

Subtitle: Making Windows Slower Part 3: Process Destruction In the summer of 2017 I wrestled with a Windows performance problem. Process destruction was slow, serialized, and was blocking the system input queue, leading to repeated short mouse-movement hangs when building … Continue reading →

Posted in Investigative Reporting, Performance, Programming | Tagged , , | 11 Comments

Making Windows Slower Part 2: Process Creation

Posted on October 15, 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 process creation on Windows … Continue reading →

Posted in Code Reliability, Investigative Reporting, Performance, Programming | Tagged , , | 16 Comments

24-core CPU and I can’t type an email (part two)

Posted on August 22, 2018 by

In my last post I promised to give more details about some rabbit holes that I went down during the investigation, including page tables, locks, WMI, and a vmmap bug. Those details are here, along with updated code samples. But … Continue reading →

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

24-core CPU and I can’t type an email (part one)

Posted on August 16, 2018 by

I wasn’t looking for trouble. I wasn’t trying to compile a huge project in the background (24-core CPU and I can’t move my mouse), I was just engaging in that most mundane of 21st century tasks, writing an email at … Continue reading →

Posted in Investigative Reporting, memory, Performance | Tagged , , , | 53 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 , , | 23 Comments

Compiler bug? Linker bug? Windows Kernel bug.

Posted on February 25, 2018 by

See the end of the post for an October 2018 bug fix update, or read the whole story: Flaky failures are the worst. In this particular investigation, which spanned twenty months, we suspected hardware failure, compiler bugs, linker bugs, and … Continue reading →

Posted in Debugging, Investigative Reporting, Programming | Tagged , , , | 65 Comments