Author Archives: brucedawson

About brucedawson

I'm a programmer, working for Google, focusing on optimization and reliability. Nothing's more fun than making code run 10x as fast. Unless it's eliminating large numbers of bugs. I also unicycle. And play (ice) hockey. And sled hockey. And juggle. And worry about whether this blog should have been called randomutf-8.

O(n^2) in CreateProcess

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 | 25 Comments

Exercises in Emulation: Xbox 360’s FMA Instruction

Years ago I worked in the Xbox 360 group at Microsoft. We were thinking about releasing a new console, and we thought it would be nice if that console could run the games of the previous console. Emulation is always … Continue reading

Posted in Floating Point | Tagged , , , , | 20 Comments

When Your Profiler Lies

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

A Not-Called Function Can Cause a 5X Slowdown

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 , , | 12 Comments

Making Windows Slower Part 2: Process Creation

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 , , | 17 Comments

Commute Challenge 2018

I’ll bet I had more fun commuting during September 2018 than you did. In April 2017 I gave myself the challenge of commuting to work using a different method every workday for a month – twenty ways in twenty days! … Continue reading

Posted in Commuting, Environment, Unicycling | 10 Comments

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

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