Why is IceCat/GuixSD slower than Firefox/Debian on headless servers?

Why is IceCat/GuixSD slower than Firefox/Debian on headless servers?

[George myglc2 Clemmer]

Running from a desktop to a headless server, and based on side-by-side
clicking, IceCat/GuixSD takes ~5x times as long as Mozilla/Debian to
respond to clicks. Further, Mozilla/Debian takes ~5x times as long as
Mozilla running on the desktop. The bottom line: IceCat/GuixSD is
unbearably slow.

Has anyone else seen this?

Is there a known IceCat/GuixSD performance problem?

Details:

Two identical headless servers with 3.4GHz E3 1240 V3 CPUs and PCI SATA
NVMe SSDs.  One runs Mozilla Firefox 45.7.0 on Debian 8.x. which was
updated a few months ago. The other runs guix 0.14.0.617-e2f37 from a
couple weeks ago. The desktop is XQuartz/MacOS 10.13.2/iMac. Both
servers are reached via the same physical 1000BaseT network.  Swapping
the server switch port/cables doesn't affect the result.

Re: Why is IceCat/GuixSD slower than Firefox/Debian on headless servers?

[Ludovic Courtès]

George myglc2 Clemmer <myglc2@gmail.com> skribis:

> Running from a desktop to a headless server, and based on side-by-side
> clicking, IceCat/GuixSD takes ~5x times as long as Mozilla/Debian to
> respond to clicks. Further, Mozilla/Debian takes ~5x times as long as
> Mozilla running on the desktop. The bottom line: IceCat/GuixSD is
> unbearably slow.
>
> Has anyone else seen this?

I use IceCat and Conkeror on GuixSD and they’re not unbearably slow.

Ludo’.

Re: Why is IceCat/GuixSD slower than Firefox/Debian on headless servers?

[Vladimir Sedach]

> Running from a desktop to a headless server, and based on side-by-side
> clicking, IceCat/GuixSD takes ~5x times as long as Mozilla/Debian to
> respond to clicks. Further, Mozilla/Debian takes ~5x times as long as
> Mozilla running on the desktop. The bottom line: IceCat/GuixSD is
> unbearably slow.
>
> Has anyone else seen this?
>
> Is there a known IceCat/GuixSD performance problem?

This sounds like an X11 protocol issue. Starting with Firefox 47,
XRender support is disabled by default:

https://www.reddit.com/r/firefox/comments/4nfmvp/ff_47_unbearable_slow_over_remote_x11/

Basically newer versions of Firefox stop using X11 correctly because
Mozilla considers X11 "technical debt," and because X11 does not support
some kinds of graphics acceleration.

Back when Wayland development started the popular ideology became that
no one needed or wanted remote graphics, if you want it use desktop
forwarding like VNC, else tough luck. A lot of people bought into that
and now we are seeing the results.

Check the value of gfx.xrender.enabled in about:config and try turning
it on/off to see if that changes the performance. It should come enabled
in Firefox 45, and is probably disabled in the newer IceCat.

If it is lack of XRender causing the problems, the more interesting
question is why running Firefox 45 remotely is so much slower than
running it on the desktop. You can try VNC forwarding to see if it is
some other X11 issue. Make sure to get Firefox 45 on the desktop for a
valid comparison.

Vladimir

Re: Why is IceCat/GuixSD slower than Firefox/Debian on headless servers?

[myglc2]

On 01/16/2018 at 11:56 Vladimir Sedach writes:

>> Running from a desktop to a headless server, and based on side-by-side
>> clicking, IceCat/GuixSD takes ~5x times as long as Mozilla/Debian to
>> respond to clicks. Further, Mozilla/Debian takes ~5x times as long as
>> Mozilla running on the desktop. The bottom line: IceCat/GuixSD is
>> unbearably slow.
>>
>> Has anyone else seen this?
>>
>> Is there a known IceCat/GuixSD performance problem?
>
> This sounds like an X11 protocol issue. Starting with Firefox 47,
> XRender support is disabled by default:
>
> https://www.reddit.com/r/firefox/comments/4nfmvp/ff_47_unbearable_slow_over_remote_x11/
>
> Basically newer versions of Firefox stop using X11 correctly because
> Mozilla considers X11 "technical debt," and because X11 does not support
> some kinds of graphics acceleration.
>
> Back when Wayland development started the popular ideology became that
> no one needed or wanted remote graphics, if you want it use desktop
> forwarding like VNC, else tough luck. A lot of people bought into that
> and now we are seeing the results.

I'm not a VNC fan (sigh)...

> Check the value of gfx.xrender.enabled in about:config and try turning
> it on/off to see if that changes the performance. It should come enabled
> in Firefox 45, and is probably disabled in the newer IceCat.

Thank you, this was really helpful. gfx.xrender.enabled=false in
IceCat/GuixSD. Enabling it made the IceCat/GuixSD performance about the
same as Firefox/Debian (which comes w/ gfx.xrender.enabled=true).

> If it is lack of XRender causing the problems, the more interesting
> question is why running Firefox 45 remotely is so much slower than
> running it on the desktop.

OK, I tested some more. It look like I was exagerating about firefox
remotely. It looks more like 1/2 as fast. ISTM that ...

Firefox>GTK+>X11(3.4GHz)<--1000BaseT-->XQuartz>Quartz(2.7GHz)>GPU

... could be 1/2 as fast as ...

Firefox>GTK+>Quartz(2.7GHz)>GPU

WDYT?

- George