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The web at maximum FPS: How WebRender gets rid of jank

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Re: The web at maximum FPS: How WebRender gets rid of jank

#101

Post by Const-me »

pohl wrote: post #13

Now that this is closer to shipping, I'm curious what impact this would have on battery life. On the one hand, this is lighting up more silicon; on the other hand: a faster race to sleep, perhaps? Have there been any measurements on what the end result is on a typical modern laptop?

Don’t know about measures. But eventually, after a couple stable FF versions are released with that new renderer, I’d expect positive impact.

GPUs are much more power efficient per FLOP. E.g. in my desktop PC, theoretical limit for the CPU is 32 FLOP/cycle * 4 cores * 3.2 GHz = 400 GFLOPS, for the GPU the theoretical limit is 2.3 TFLOPS. TDP for them is 84W CPU, 120W GPU.

A GPU has vast majority of transistors actually doing math, while in a CPU core, large percentage of these transistors are doing something else. Cache synchronization/invalidation, instructions reordering, branch prediction, indirect branch prediction (GPU has none of that), instruction fetch and decode (for GPU that’s shared between a group of cores who execute same instructions in lockstep).

Re: The web at maximum FPS: How WebRender gets rid of jank

#102

Post by drudru11 »

pcwalton wrote: post #17
azinman2 wrote: post #15

Won’t this cause a lot of work to be done for a blinking cursor? Curious about battery drain, I/O overhead, General CPU usage, etc.

With a compositor you're already drawing every pixel every frame on the GPU, whether it's just a cursor blinking or not. The WR approach basically only adds a negligible amount of vertex shading time.

But only on a change... So if the cursor blinks every second, you would be doing the render/composite at that point.

Re: The web at maximum FPS: How WebRender gets rid of jank

#103

Post by fjksksvdjsjd »

htn369 wrote: post #94
pimeys wrote: post #87

Earlier quoted context omitted.

I've been working professionally with Rust for a year now. When I got over the first wall, it has become the best tool I've had for creating backend applications. I have history with at least nine different languages during my professional career, but nothing comes close giving the confidence and ergonomics than the tools Rust ecosystem provides. Firefox, especially the new Quantum version is awesome. But Rust as a s…

How complete is the Rust library and complementing open source projects comparing with golang?

It’s good.

Net/http is still less mature, but this an absolutey massive golang ecosystem. You can certainly write http clients and servers today.

Unicode, string processing, regex—all of these have performant, stable implementations, either in std or in crates. Recently i’ve been doing audio processing in rust; the code there is at least as good as the equivalent in go. Overall I’d say I haven’t had issues finding a package for something in a couple years, though the quality varies from “has a full support community” to “DIY if you need something”.

However, rust really shines with datastructures. Heap? Btree? Doubly linked lists? It’s all high quality, performant, and type-safe code (though the internals are unsafe as hell), which was my major pain point in go. Doing anything with a typed datastructure feels a lot like copy/paste coding in go, though apparently templates formalize this.

Re: The web at maximum FPS: How WebRender gets rid of jank

#104

Post by amelius »

> What if we stopped trying to guess what layers we need? What if we removed this boundary between painting and compositing and just went back to painting every pixel on every frame?

This feels a bit like cheating. Not all devices have a GPU. Would Firefox be slow on those devices?

Also, pages can become arbitrarily complicated. This means that an approach where compositing is used can still be faster in certain circumstances.

Re: The web at maximum FPS: How WebRender gets rid of jank

#105

Post by aneutron »

amelius wrote: post #104

> What if we stopped trying to guess what layers we need? What if we removed this boundary between painting and compositing and just went back to painting every pixel on every frame? This feels a bit like cheating. Not all devices have a GPU. Would Firefox be slow on those devices? Also, pages can become arbitrarily complicated. This means that an approach where compositing is used can still be faster in certain circ…

Actually, virtually every device the average grade consumer uses, has a GPU. For instance, even Atom processors have GPUs. Granted, they don't have as much cores as a full-fledged nVidia GPU, nor as much dedicated memory, but they are still GPU with several tens of cores and specialized APIs that were designed specifically for the tasks at hand. Plus, they offload (ish) the CPU.

Re: The web at maximum FPS: How WebRender gets rid of jank

#106

Post by amelius »

aneutron wrote: post #105
amelius wrote: post #104

> What if we stopped trying to guess what layers we need? What if we removed this boundary between painting and compositing and just went back to painting every pixel on every frame? This feels a bit like cheating. Not all devices have a GPU. Would Firefox be slow on those devices? Also, pages can become arbitrarily complicated. This means that an approach where compositing is used can still be faster in certain circ…

Actually, virtually every device the average grade consumer uses, has a GPU. For instance, even Atom processors have GPUs. Granted, they don't have as much cores as a full-fledged nVidia GPU, nor as much dedicated memory, but they are still GPU with several tens of cores and specialized APIs that were designed specifically for the tasks at hand. Plus, they offload (ish) the CPU.

How about energy use?

PS: And my second point?

Re: The web at maximum FPS: How WebRender gets rid of jank

#107

Post by mncharity »

ngokevin wrote: post #48

I don't think it would help WebVR (maybe in the future rendering DOM as textures, but it'd be limited to only 2D), but today WebVR applications goes through a different pipeline, running purely on WebGL.

Some of us are running alternate WebVR stacks. :) On a Vive, playing with the 3D demo, it looks like I'm getting ~50 minimally-readable lines of text, with no motion, and no lens correction (integrated graphics). Should be ~80ish with corrected chromatic aberration. Which is pretty good for the low-angular-resolution and PenTile Vive. It's comparable to the usual hand-tuned pixel fonts rendered flat (part of that is PenTile pain).

Re: The web at maximum FPS: How WebRender gets rid of jank

#108

Post by fb03 »

pimeys wrote: post #87
JepZ wrote: post #80

While I would consider myself more a Golang fan than a Rust fan, I am impressed by the speed by which the Mozilla team is changing fundamental parts of their browser and somehow I believe rust has something to do with that speed.

I've been working professionally with Rust for a year now. When I got over the first wall, it has become the best tool I've had for creating backend applications. I have history with at least nine different languages during my professional career, but nothing comes close giving the confidence and ergonomics than the tools Rust ecosystem provides. Firefox, especially the new Quantum version is awesome. But Rust as a s…

nice! can you talk more about Rust's tooling? How do you debug? What IDE or text editor do you feel comfy with? Do you have/use/need autocomplete?

I'm coming from a a Python background and I'm too spoiled by Pycharm's insane tooling and autocomplete and stuff.. I wanna trail de Rust path too!

thanks in advance.

Re: The web at maximum FPS: How WebRender gets rid of jank

#109

Post by steveklabnik »

markdog12 wrote: post #58
SomeCallMeTim wrote: post #14

Earlier quoted context omitted.

Speaking of batching, I look at this demo [1] on my mobile phone, and I can get ~3500 sprites without dropping below 60FPS. A web page may not be able to reuse as much image data, I know. But smart game engines frequently look for ways to better batch sprites. And technically speaking, if you're using a Z-buffer, you don't need to sort opaque layers at all . You can draw the layers in back and then draw more layers i…

Interestingly, WebRender renders that demo at about 2fps. It's obviously a bug though, if you hold in the mouse, it's 60fps. Win 10, latest nightly, WebRender enabled

Weird; I'm on Win 10 with the latest nightly and WebRender enabled, I'm still getting 60fps with 10,000 bunnies. Maybe file a bug?

Re: The web at maximum FPS: How WebRender gets rid of jank

#110

Post by nachtigall »

lwansbrough wrote: post #30
pohl wrote: post #13

Now that this is closer to shipping, I'm curious what impact this would have on battery life. On the one hand, this is lighting up more silicon; on the other hand: a faster race to sleep, perhaps? Have there been any measurements on what the end result is on a typical modern laptop?

I know it’s not officially released, so I’m hoping it gets fixed, but FF57 rips through my Mac’s battery life and runs insanely hot on simple JS apps. I still use it daily because it generally works, but there are a few apps I just have to go to Chrome for.

I guess you should open a bug report on https://bugzilla.mozilla.org/

Mention Quantum Flow and "performance" in it. It worked for me in the past that performance issues I had were solved within a few weeks or days.

Make sure to attach a performance profile with https://perf-html.io/ using the linked add-on there.

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