Category Archives: uiforetw

Finding Windows HANDLE leaks, in Chromium and others

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 , | 14 Comments

What Outranks Thread Priority?

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

Creating a Public Symbol Server, Easily

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#

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

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

Heap Snapshots–Tracing All Heap Allocations

I’ve recently started using heap snapshots on Windows to track heap allocations. I was able to use heap snapshots to record call stacks for all outstanding allocations in Chrome’s browser process over a full two weeks, letting me account for … Continue reading

Posted in Documentation, Performance, Programming, uiforetw, xperf | Tagged , | 22 Comments

63 Cores Blocked by Seven Instructions

I seem to have a habit of writing about super powerful machines whose many cores are laid low by misuse of locks. So. Yeah. It’s that again. But this one seems particularly impressive. I mean, how often do you have … Continue reading

Posted in Investigative Reporting, Performance, Programming, Quadratic, uiforetw, xperf | Tagged , , | 12 Comments

Taskbar Latency and Kernel Calls

I work quickly on my computer and I get frustrated when I am forced to wait on an operation that should be fast. A persistent nuisance on my over-powered home laptop is that closing windows on the taskbar is slow. … Continue reading

Posted in Investigative Reporting, Performance, uiforetw, xperf | Tagged , , , | 33 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 , , | 12 Comments

What is Windows *doing* while hogging that lock

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 , , | 12 Comments