Ancient Bug Discovered in the Visual Metrics Processing Script
Recently, we had an odd regression in our page load tests. You can find that bug here. The regression was quite large, but when a developer investigated, they found that … Read more
Improving the Test Selection Experience with Mach Try Perf
If you’ve ever tried to figure out what performance tests you should run to target some component, and got lost in the nomenclature of our CI task names, then you’re … Read more
The Firefox Profiler team was at FOSDEM 2023
The Free and Open source Software Developers’ European Meeting (FOSDEM) 2023 took place on the 4th and 5th of February. This was the first in-person FOSDEM since 2020, and for … Read more
Announcing side-by-side videos for performance regressions
Early in the fall, I was talking about integrating the side-by-side tool in Continuous Integration (CI). This started as a script for generating a side-by-side comparison between two page load … Read more
Understanding Performance Impact
A few years ago, a small group of engineers at Mozilla introduced a process to identify the tasks that would have the greatest impact on the performance of Firefox. They … Read more
What’s new with the Firefox Profiler? (Q3 2022)
As the Perf-Tools team, we are responsible for the Firefox Profiler. This newsletter gives an overview of the new features and improvements we’ve made in the third quarter of 2022. … Read more
A different perspective
Usually, in our articles, we talk about performance from the performance engineer’s perspective, but in this one, I want to take a step back and look at it from another … Read more
Performance Tools Newsletter (H1 2022)
As the Perf-Tools team, we are responsible for the Firefox Profiler. This newsletter gives an overview of the new features and improvements we’ve done in the first half of 2022. … Read more
Migrating to Browsertime for Performance Testing
Originally, we used a Web Extension for doing performance testing on Firefox in our Raptor test harness. But, we needed to add new features such as visual metrics, so in … Read more
Reworking our Visual Metrics Processing System
Our visual metrics processing system used to use two separate machines to produce visual metrics from our pageload tests. In this post, I’ll describe how we moved to a single-machine … Read more
Introducing A New Performance Comparison Tool – PerfCompare
Introduction I have been a member of the performance test team for the past two and a half years. During that time, the performance team has had many discussions about … Read more
Prioritized Task Scheduling API is Prototyped in Nightly
In bug 1734997, we prototyped the Prioritized Task Scheduling API. Having the API prototyped empowers us to experiment with the benefits of this API. It is enabled by default in … Read more