2019-12-09 21:03


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

Ma ciekawe wpisy nt. debugowania

Why do I hit so many crazy problems?

I work on the Windows version of Chrome, and one of my tasks is optimizing its build system, which requires doing a lot of test builds. Building chrome involves creating between 28,000 and 37,000 processes, depending on build settings. When using our distributed build system (goma) these processes are created and destroyed very quickly – my fastest full build ever took about 200 seconds. This aggressive process creation has revealed a number of interesting bugs, mostly in Windows or its components:

Zombie Processes are Eating your Memory

I held my breath and killed CcmExec.exe, unsure of what would happen:
The results were as dramatic as I could imagine. As I said earlier, the Windows kernel is well written and when a process is killed then all of its resources are freed. So, those 508,000 handles that were owned by CcmExec.exe were abruptly closed and my available memory went up by 32 GB!

O(n^2), again, now in WMI

O(n^2) is the sweet spot of badly scaling algorithms: fast enough to make it into production, but slow enough to make things fall down once it gets there.


63 Cores Blocked by Seven Instructions

24-core CPU and I can’t move my mouse


Rozbolała mnie głowa. Bajer :D