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. 2010s in review tells more: https://twitter.com/BruceDawson0xB/status/1212101533015298048

Floating Point in the Browser, Part 2: Bad Epsilon

Posted on October 11, 2020 by brucedawson

A few years ago I did a lot of thinking and writing about floating-point math. It was good fun, and I learned a lot in the process, but sometimes I go a long time without actually using that hard-earned knowledge. … Continue reading →

Posted in Chromium, Computers and Internet, Floating Point | Tagged , | 2 Comments

Windows Timer Resolution: The Great Rule Change

Posted on October 4, 2020 by brucedawson

The behavior of the Windows scheduler changed significantly in Windows 10 2004 (aka, the April 2020 version of Windows), in a way that will break a few applications, and there appears to have been no announcement, and the documentation has … Continue reading →

Posted in Environment, Investigative Reporting, Performance, Rants | Tagged , | 63 Comments

Floating Point in the Browser, Part 1: Impossible Expectations

Posted on September 27, 2020 by brucedawson

A few years ago I did a lot of thinking and writing about floating-point math. It was good fun, and I learned a lot in the process, but sometimes I go a long time without actually using that hard-earned knowledge. … Continue reading →

Posted in Chromium, Computers and Internet, Floating Point | Tagged , | 21 Comments

The Easy Ones – Three Bugs Hiding in the Open

Posted on August 30, 2020 by brucedawson

I write a lot about investigations into tricky bugs – CPU defects, kernel bugs, transient 4-GB memory allocations – but most bugs are not that esoteric. Sometimes tracking down a bug is as simple as paying attention to server dashboards, … Continue reading →

Posted in Bugs, Code analysis, Code Reliability, Debugging, Floating Point, Linux, Performance | Tagged | 17 Comments

GDI leaks and the importance of luck

Posted on May 10, 2020 by brucedawson

In May 2019 I was asked to look at a potentially serious Chrome bug. I initially misdiagnosed it as unimportant, thus wasting two valuable weeks, and when I rejoined the investigation it was the number one browser-process crash in Chrome’s … Continue reading →

Posted in Bugs, Chromium, Debugging, Programming | Tagged | 25 Comments

What Outranks Thread Priority?

Posted on April 14, 2020 by brucedawson

This investigation started, as so many of mine do, with me minding my own business, not looking for trouble. In this case all I was doing was opening my laptop lid and trying to log on. The first few times … Continue reading →

Posted in Investigative Reporting, Performance, uiforetw, xperf | Tagged , , | 7 Comments

Big Project Build Times–Chromium

Posted on March 30, 2020 by brucedawson

A twitter discussion on build times and source-file sizes got me interested in doing some analysis of Chromium build times. I had some ideas about what I would find (lots of small source files causing much of the build time) … Continue reading →

Posted in Chromium, Performance, Programming | Tagged , | 23 Comments

Creating a Public Symbol Server, Easily

Posted on March 14, 2020 by brucedawson

I’ve been a big fan of symbol servers for years. They are a part of the Microsoft/Windows ecosystem that is far better than anything I have seen for other operating systems. With Microsoft’s and Chrome’s symbol servers configured I can … Continue reading →

Posted in Debugging, Programming, Symbols, uiforetw | Tagged | 15 Comments

Bulk ETW Trace Analysis in C#

Posted on January 5, 2020 by brucedawson

ETW traces record a wealth of information about how a Windows system is behaving. When analyzing a new and unknown problem there is no replacement for loading the trace into WPA and following the clues to a solution. The thrill … Continue reading →

Posted in uiforetw, xperf | Tagged , | 9 Comments

O(n^2), again, now in WMI

Posted on December 8, 2019 by brucedawson

I recently hit some multi-minute delays on my workstation. After investigating I found that the problem was due to a lock being held for five minutes, and during that time the lock-holder was mostly just spinning in a nine-instruction loop. … Continue reading →

Posted in Investigative Reporting, Programming, Quadratic, Rants, uiforetw, xperf | Tagged , , , , | 23 Comments