Category Archives: Investigative Reporting

32 MiB Working Sets on a 64 GiB machine

Posted on October 1, 2023 by brucedawson

Memory is a relatively scarce resource on many consumer computers, so a feature to limit how much memory a process uses seems like a good idea, and Microsoft did indeed implement such a feature. However: They didn’t document this (!) … Continue reading →

Posted in Computers and Internet, Investigative Reporting, memory, Performance, Programming, uiforetw, xperf | Tagged , , | 10 Comments

No Start Menu for You

Posted on January 17, 2023 by brucedawson

I tend to launch most programs on my Windows 10 laptop by typing the <Win> key, then a few letters of the program name, and then hitting enter. On my powerful laptop (SSD and 32 GB of RAM) this process … Continue reading →

Posted in Code Reliability, Debugging, Investigative Reporting, Performance, Programming, Rants, uiforetw, xperf | Tagged , , | 28 Comments

Compiler Tricks to Avoid ABI-Induced Crashes

Posted on December 14, 2022 by brucedawson

Last month I wrote about an odd crash that was hitting a few Chrome users. Something was corrupting the XMM7 register and that was causing Chrome to crash. We fixed a couple of bugs in Chrome and we were able … Continue reading →

Posted in Chromium, Debugging, Investigative Reporting, Symbols | Tagged , , , | 2 Comments

Please Restore Our Registers When You’re Done With Them

Posted on November 21, 2022 by brucedawson

“Hey, you. Yes you, that function over there. When you’re cleaning up please remember to restore all of my registers. Yes, that one too – what do you think this is, Linux?” That’s the problem I was dealing with in … Continue reading →

Posted in Chromium, Debugging, Investigative Reporting, Symbols | Tagged , , | 25 Comments

Why Modern Software is Slow–Windows Voice Recorder

Posted on September 29, 2022 by brucedawson

I apologize for this title because there are many things that can make modern software slow. Blindly applying one explanation without a bit of investigation is the software equivalent of a cargo cult. That said, this post describes one example … Continue reading →

Posted in Investigative Reporting, Performance, uiforetw, xperf | Tagged , , | 39 Comments

Slower Memory Zeroing Through Parallelism

Posted on July 11, 2022 by brucedawson

While investigating some performance mysteries in Chrome I discovered that Microsoft had parallelized how they zero memory, and in some cases this was making it a lot slower. This slowdown may be mitigated in Windows 11 but in the latest … Continue reading →

Posted in Investigative Reporting, Performance, uiforetw | Tagged , | 13 Comments

Determinism Bugs, Part Two, Kernel32.dll

Posted on January 6, 2022 by brucedawson

It was literally the day after I cracked the __FILE__ determinism bug that I hit a completely different build determinism issue. I was asked to investigate why the Chrome build number reported for Chrome crashes on Windows 11 was lagging … Continue reading →

Posted in Bugs, Chromium, Computers and Internet, Investigative Reporting, Programming, Symbols | Tagged , , | 19 Comments

Finding Windows HANDLE leaks, in Chromium and others

Posted on July 25, 2021 by brucedawson

Three years ago I found a 32 GB memory leak caused by CcmExec.exe failing to close process handles. That bug is fixed, but ever since then I have had the handles column in  Windows Task Manager enabled, just in case … Continue reading →

Posted in Bugs, Code Reliability, Investigative Reporting, uiforetw, xperf | Tagged , | 20 Comments

Arranging Invisible Icons in Quadratic Time

Posted on February 16, 2021 by brucedawson

Near the end of January I was pointed to a twitter thread where a Windows user with a powerful machine was hitting random hangs in explorer. Lots of unscientific theories were being proposed. I don’t generally do random analysis of … Continue reading →

Posted in Investigative Reporting, Performance, Programming, Quadratic, Rants, Symbols | Tagged , | 18 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 , | 98 Comments