4 ms·

When more and more parts of FF are written in rust, I thought FF will get a lot faster. But for the past 1 year, I can only see marginal improvements w.r.t spee

When more and more parts of FF are written in rust, I thought FF will get a lot faster. But for the past 1 year, I can only see marginal improvements w.r.t speed. And occasionally FF hangs when I have 20 tabs opened.

rs_rs_rs_rs_rs 3y ago
Why would you think that? Rust is certainly a little bit slower than C/C++
- mnd999 3y ago
  [flagged]
- qup 3y ago
  Everything I've read says that you're right in theory, but in practice, rust rewrites tend to outperform. At Mozilla's level, though, I wouldn't necessarily expect that to hold water. They should be able to write great code in either language.
  - lxgr 3y ago
    I wouldn’t be surprised if rewrites in any language (including the original one!) would have a tendency to outperform. A rewrite (by people familiar with the original and its pain points) is an excellent opportunity to optimize.
  - lrem 3y ago
    Eh, no. A rewrite is pretty much always better. You now know the problem you’re actually facing. Drop all the little wrong assumptions. And in general are better equipped than the last time. I vaguely remember reading here about a company that slapped a backend together in Python. When they took off, the compute costs stung, so they rewrote in Go. Saved most of the bill. Some time later that started creaking, so they rewrote again. In Python, but managed to save most of the bill again.
- pcwalton 3y ago
  They use the same compiler backend and you can generate pretty much any LLVM IR you want with Rust. You can argue about the performance characteristics of the kind of code the language encourages you to write, but a blanket statement like that isn't true.
bingemaker 3y ago
Not sure why am I getting down voted for posting an observation :shrug:
- hoppyhoppy2 3y ago
  >Please don't comment about the voting on comments. It never does any good, and it makes boring reading. https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html
bpbp-mango 3y ago
After the CSS parser and Webrender has there been any more new rust components?
littlestymaar 3y ago
> And occasionally FF hangs when I have 20 tabs opened. ? That's really suprising to read when on my low-end laptop from 2012, Firefox runs with 20 open tabs without ever facing any issue (I have something like 30 tabs open right now).

rs_rs_rs_rs_rs 3y ago

Why would you think that? Rust is certainly a little bit slower than C/C++

mnd999 3y ago
[flagged]
qup 3y ago
Everything I've read says that you're right in theory, but in practice, rust rewrites tend to outperform. At Mozilla's level, though, I wouldn't necessarily expect that to hold water. They should be able to write great code in either language.
- lxgr 3y ago
  I wouldn’t be surprised if rewrites in any language (including the original one!) would have a tendency to outperform. A rewrite (by people familiar with the original and its pain points) is an excellent opportunity to optimize.
- lrem 3y ago
  Eh, no. A rewrite is pretty much always better. You now know the problem you’re actually facing. Drop all the little wrong assumptions. And in general are better equipped than the last time. I vaguely remember reading here about a company that slapped a backend together in Python. When they took off, the compute costs stung, so they rewrote in Go. Saved most of the bill. Some time later that started creaking, so they rewrote again. In Python, but managed to save most of the bill again.
pcwalton 3y ago
They use the same compiler backend and you can generate pretty much any LLVM IR you want with Rust. You can argue about the performance characteristics of the kind of code the language encourages you to write, but a blanket statement like that isn't true.

bingemaker 3y ago

Not sure why am I getting down voted for posting an observation :shrug:

hoppyhoppy2 3y ago
>Please don't comment about the voting on comments. It never does any good, and it makes boring reading. https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html

bpbp-mango 3y ago

After the CSS parser and Webrender has there been any more new rust components?

littlestymaar 3y ago

> And occasionally FF hangs when I have 20 tabs opened. ? That's really suprising to read when on my low-end laptop from 2012, Firefox runs with 20 open tabs without ever facing any issue (I have something like 30 tabs open right now).