Recently, I landed some improvements to IPC profiling support for Firefox: we're now able to collect timings for each "phase" of an IPC message as it travels from the sender to its recipient. Now, rather than just recording the start and end time, we also record when we begin/end sending bytes on the sender's IO thread, and when we've finished receiving bytes on the recipient's IO thread. This should help people looking to understand what's going on with our multiprocessing, since it's now clearer what the underlying cause of IPC slowness is.
To collect IPC messages with full timings, you'll need to enable IPC message support in the profiler (about:profiler -> Features -> IPC Messages), as well as explicitly profiling the IPC IO threads by adding `Gecko_IOThread` and `Chrome_ChildThread` to the list of threads to be profiled. If you'd like more details, screenshots, etc, this feature is documented here: <https://profiler.firefox.com/docs/#/./ipc-messages>. One obvious limitation of this feature at the moment is that it can be difficult to evaluate the *overall* IPC message performance. In the future, I plan to provide a better high-level visualization to make this easier. As always, if you have questions, suggestions, etc, feel free to send me a message! - Jim _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
