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Comment by oblio | Hacker News Reader

Isn't Chrome multi-process per-tab? Unless I'm misunderstanding, Firefox's e10s will create just 2 processes: UI / content.

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The goal must be a single controller ("UI") process and multiple content processes for each tab, otherwise they'll be missing out on the advantages of a multiprocess model, namely, stability and isolation.

They're first going to do two processes, probably for debugging without too many moving parts, then multiprocess. See https://wiki.mozilla.org/Electrolysis#Schedule_and_Status and https://wiki.mozilla.org/Electrolysis/Multiple_content_proce....

It's not supported, but you can go into about:config and change dom.ipc.processCount to a number higher than one. I haven't had any trouble running at the number of hardware threads, minus one for the UI.

Ok now that I've read all the problems that could cause https://bugzilla.mozilla.org/showdependencytree.cgi?id=e10s-... , I feel bad about recommending it.

> The goal must be [...] multiple content processes for each tab

According to the wiki page you linked, it doesn't seem to be the goal for them:

"The (practically) unlimited process count is on some platforms not a realistic goal, and having a separate process for each open site instances or even sites does not seem like a reachable goal (for now at least). Which means using content processes as a security membrane cannot be a goal either."

If this is true, I don't see any advantages of e10s introduction.

They're going to find out that managing processes by themselves is going to be very difficult (similar to M:N threading), and opt for a Chrome-like model where each tab is its own process.

That was the original Chrome model but they switched to M:N.

I don't think going full process per tab is the answer either, I think that some kind of system that adds additional processes for heavy tabs while keeping as many on single content processes would be a good middle ground.

I thought the plan was for Firefox to use the same process-per-tab model as Chrome, but this post does seem to imply that it's just 2 - "we’re using project Electrolysis to split Firefox into a UI process and a content process."

They also go on to say that "After that, we’ll be working on support for multiple content processes.", so I assume the plan is to have one perocess-per-tab eventually. I'm surprised they aren't there already though, considering this has been in the works for a few years now.

There was a period where electrolysis didn't receive much work, and then there was a second push to get it working. That's why it seems to be taking so long.

As for process-per-tab, I can't find anything official about it on the bug tracker. The problem with that option is it leads to quite high memory usage, and hides the existence of memory leaks (chrome really likes to eat my ram). We'll have to see how memory usage goes as they experiment with multiple content processes.

It is starting with just two for now, but will be increased after more optimization. There's a setting you can modify in about:config that will allow you to manually set the number of processes if you want to experiment with it.

source: https://www.reddit.com/r/firefox/comments/4hmii4/firefoxs_ap...

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