Taras Glek

Traditionally Mozilla measured Firefox performance with a set of performance tests called Talos. For features not covered by Talos developers benchmarked individual features themselves. However, it turns it is extremely difficult to design a representative testsuite. Reproducing performance problems is often harder than fixing them. Telemetry is a way to measure Firefox performance & usage in the field. It allows developers to insert lightweight probes and then use them to track how Firefox behaves in the wild. We have been using Telemetry to improve Firefox since version 7. We will soon roll out Telemetry to addon developers so they can benefit from the same infrastructure. This talk will cover how Telemetry is used and the kinds of problems it helped us fix so far.

Linker, compiler, runtime linker and the kernel can be improved to start applications significantly faster.

Optimizing application startup is hard, even measuring how long an application takes to start is a non-trivial problem. This talk will consist of 3 main parts: 1. Ways of measuring IO patterns [on startup] using systemtap, gdb, valgrind 2. How to optimize IO patterns on startup given the limitations in existing tools 3. A list of proposed changes in the kernel, ld, ld.so, gcc that could significantly speed up application startup on Linux. Additionally, the talk will compare application startup on Linux against other major platforms.