Am I wasting my time with from source compiles?

cybertorture · 2011-11-23 03:00:12

Just wonder - Is it not all about Your choice ?

ewaller · 2011-11-23 03:55:28

I am a recovering Gentoo user. I really did enjoy that distribution. I still do. Like Arch, they had a terrific community in which you could communicate with some very talented people. It was a tremendous experience in which I really learned what happens under the hood -- and the hell that is the developers life when trying to keep everything compatible with everything.

I was able to optimize the heck out of things -- and it did not make a hill of beans difference to the performance of the system from a human's point of view. I have used Linux in a few real-time embedded applications with hard deadlines; a scenario in which the optimizations were evident.

For a basic desktop, it is a waste of time.

bwat47 · 2011-11-23 05:32:25

I don't think the performance improvements are big enough to make it worthwile IMO.

nomilieu · 2011-11-23 14:46:02

ewaller wrote:

I am a recovering Gentoo user.

Ha, I recently went back to Gentoo on my home desktop (the previously mentioned Gentoo box).
Mostly it was a decision to make my life easier, even if compiling software takes a bit of extra time.
It certainly wasn't for performance. I haven't even bothered yet to ditch genkernel.

nomilieu · 2011-11-23 14:55:58

ngoonee wrote:

I'd be interested to know of specific cases where compiling from source works and putting the same commands into the PKGBUILD doesn't.

Aren't those basically the same thing?
A better comparison would be compiling (either manually or with a PKGBUILD) vs. installing from the Arch repos.

Grinch · 2011-11-23 17:13:57

Gusar wrote:

JGC wrote:
You could gain some extra speed with multimedia programs like mplayer and x264 by recompiling native though.
People keep repeating that, but it's completely false. These multimedia apps gain all their speed from hand-written assembly, not from compiler flags. All this assembly is compiled in *always*, and then runtime cpu detection determines which codepaths to run.

IIRC the deblock and denoise filters in x264 are not optimized in assembly and thus potentially benefits from higher optimization, but I may be wrong. Also when I was encoding interlaced stuff with Handbrake I recall getting a performance boost out of the yadif deinterlacer when compiled with more aggressive optimizations. In essence though I certainly agree, the hot codepaths in x264 are heavily hand-optimized using assembly and there's really no worthwhile gains to be had from recompiling with more aggressive flags. Same goes for many other encoders which also uses hand-optimized assembly.

And even if there are notable gains to be had in recompiling an application, unless you are really using the application on a very regular basis, or unless the increased performance enhances the use of the application (like getting smoother gameplay in a game/emulator or something) then I don't think there's any real 'practical' benefit which would outweigh the extra time spent on recompiling with more aggressive flags. YMMV and all that.

Vamp898 · 2011-11-23 17:34:08

Most people mesure performance on how fast a desktop is and things like that.

Gentoo doesnt speed up your harddisk and the harddisk is the largest bottleneck.

Gentoo does nothing, it just gives you tools to do things yourself.

If you compile your stuff with -march=native your system should normally be faster, but you wont see that increase in lot of cases because your harddisk is to slow to take the advantage.

But Bug-Hunting is much more easy with Gentoo, you can compile everything with Debug Symbols, strip those debug symbols and put them in a separate directory.

That way you have small binaries + debug symbols. So whatever crashes, you are always able to do full backtraces with all debug symbols.

Also if you run a lot of stuff where the HDD speed is not that important, you will see a speed increase.

And for sure you have a clean system.

On Archlinux you can´t have a full KDE System without GTK+ and a very lot of GNOME Stuff.

And Gentoo you can use KDE completely without even having GTK+ installed. Also you can put out pulseaudio completely, gstreamer, bluetooth, infrared all that "nobody needs it but applications was compiled with support for it so it is a dependency" stuff

But Gentoo consumes a lot of time and if you dont learn from it and dont feel the difference you wont have any advantage except the fun optimising your system as much as possible.

Last edited by Vamp898 (2011-11-23 17:53:41)

fukawi2 · 2011-11-23 21:59:49

ngoonee wrote:

I'd be interested to know of specific cases where compiling from source works and putting the same commands into the PKGBUILD doesn't. In most such cases upstream is doing something wrong (hardcoded directories etc., not using the standard tools).

I came across an instance last night with nagios-nsca. makepkg sets additional env vars that I don't have in my normal environment, in this case CFLAGS and LDFLAGS. Something in the extra flags caused compilation (make all) to fail in the PKGBUILD even though it worked doing it manually. (Of course, `unset CFLAGS LDFLAGS` in the PKGBUILD makes it work)

Last edited by fukawi2 (2011-11-23 22:00:14)

ngoonee · 2011-11-24 01:50:28

fukawi2 wrote:

ngoonee wrote:
I'd be interested to know of specific cases where compiling from source works and putting the same commands into the PKGBUILD doesn't. In most such cases upstream is doing something wrong (hardcoded directories etc., not using the standard tools).
I came across an instance last night with nagios-nsca. makepkg sets additional env vars that I don't have in my normal environment, in this case CFLAGS and LDFLAGS. Something in the extra flags caused compilation (make all) to fail in the PKGBUILD even though it worked doing it manually. (Of course, `unset CFLAGS LDFLAGS` in the PKGBUILD makes it work)

Those cases most likely indicate either upstream making unwarranted assumptions about the compilation environment or not communicating them properly to potential users (for example statements on websites that LDFLAGs should be such-and-such, which some projects do have).

nomilieu wrote:

ngoonee wrote:
I'd be interested to know of specific cases where compiling from source works and putting the same commands into the PKGBUILD doesn't.
Aren't those basically the same thing?
A better comparison would be compiling (either manually or with a PKGBUILD) vs. installing from the Arch repos.

See above, compiling from source and putting the same code into a PKGBUILD are not exactly the same thing.

nomilieu · 2011-11-24 04:15:26

ngoonee wrote:

See above, compiling from source and putting the same code into a PKGBUILD are not exactly the same thing.

It's a language issue.
It'd be like a Gentoo user talking about differences in compiling vs. emerging, rather than compiling and installing manually vs. emerging.

Apologies, carry on.

krum · 2011-11-25 12:20:15

Time = money

Don't waste time, but waste some money to buy a SSD.
It's the better human measurable enhancement you can get on a computer.

Arch Linux

#26 2011-11-23 03:00:12

Re: Am I wasting my time with from source compiles?

#27 2011-11-23 03:55:28

Re: Am I wasting my time with from source compiles?

#28 2011-11-23 05:32:25

Re: Am I wasting my time with from source compiles?

#29 2011-11-23 14:46:02

Re: Am I wasting my time with from source compiles?

#30 2011-11-23 14:55:58

Re: Am I wasting my time with from source compiles?

#31 2011-11-23 17:13:57

Re: Am I wasting my time with from source compiles?

#32 2011-11-23 17:34:08

Re: Am I wasting my time with from source compiles?

#33 2011-11-23 21:59:49

Re: Am I wasting my time with from source compiles?

#34 2011-11-24 01:50:28

Re: Am I wasting my time with from source compiles?

#35 2011-11-24 04:15:26

Re: Am I wasting my time with from source compiles?

#36 2011-11-25 12:20:15

Re: Am I wasting my time with from source compiles?

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