I have taken my time to go through all kernel options one by one to learn more and to see if I got some increase in performance. The result is there is not much difference. I got about one or two seconds from my boot time, but if I get some new hardware I have to compile it again. Also, pre-compiled images are smaller than source ones to download, there's time and CPU involved and so on...


CONFIG_NR_TTY_DEVICES=63:

I've taken this piece of text from some Mandriva devel blog: After decyphering strace logs, we discovered about 256 legacy ptys were created by kernel, which are no longer needed for most usage. With help from our kernel team, we reduce the default value of those ptys to 0 (it can be increased dynamically). Gain in for full boot time and perceived boot time : 2s.

I don't really know how to make them increase dinamically, but does anyone nowadays use more than 12? Couldn't we shave a bit of boot time on this one?


CONFIG_TCP_CONG_*:

What is the main advantage of using TCP Vegas by default? I mean, you must have tried them all and decided on this one. What advantages did you notice, and on what kind of internet connection? I'm using 3G and I wonder if I benefit from Vegas or would benefit from Westhood, or if the difference is not really noticeable...


CONFIG_LOGO_ZEN_CLUT224=y:

This is a bit hard to say, but I find the Zen logo a bit too religious, and I feel unwell to see it during the boot. Old Liquorix logo was more neutral and looked much better! That is just my opinion!


Also, there was another power regression recently (after 3.4). Do you know about it and if it was fixed? I'm still on 3.4 because of that.

Thanks!
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Whoa, a lot of questions, let me start from the top.

Boot time is not something I benchmark. I find that to be a poor test in general, since you're depending a lot more on probability than anything else. There's so many things running concurrently, some needing more disk I/O than others, and a minor tweak in the disk scheduler could make major changes in the boot time. Also, a disk scheduler or process scheduler change that reduces boot time, can also ruin desktop behavior... so this is not a metric worth looking at, unless there's a dramatic difference.

CONFIG_NR_TTY_DEVICES=63: Ya, lets reduce that to 9. X starts on the 7th tty, and you can switch back and forth between a plain terminal and X by hitting ctrl+alt+f1 and ctrl+alt+f7. If one needs more terminals than 9, they need to find a new way to manage terminals like screen, or a real desktop environment running X like KDE with Konsole.

TCP_VEGAS: This congestion algorithm is the only one that reduces the throughput of a tcp congestion when it detects an increase in latency from the transmitting end. Without this congestion control, you would need really fancy QoS to manage your uploads, torrents, movie streams, low latency online gaming, etc. When setup from a desktop level, you have control of the shared network resource and can fairly upload and download and full speed without detriment to the latency of existing and new tcp connections.

ZEN_CLUT224: This is just a stoned penguin enjoying its life on your boot screen. If you look closer, the penguin appears to be holding some Buddhist related items, but that's not something I really paid any attention to. The real point is that the penguin is feeling zen.

This one was eventually going to be phased out, I just need a new logo for Liquorix. I'm looking for something that's similar to the wine project, but instead it's a tumbler glass with a clear liquid on the rocks.
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re virtual terminals, I think it's not unheard of to have this many:

consoles: tty0-6
x - tty 7-8
ssh sessions: each get a tty I believe

Then it appears that every app that uses a terminal emulator window also gets its own tty, that can be a LOT of tty's.

I just this week was testing tty numbers on my system and one test showed tty 14, so I think there might be more than you realize being used on a normal desktop



These are from my desktop. So I'd say be a bit careful cutting those too far, I'd say leave it at the default until you really know that people don't use less than x ever.

without even trying I show 21 so far.

I figured it out, every new application in x that runs a terminal emulator, whether it's konsole, gterminal, or kate or dolphin, opens a new tty session, so definitely leave that at 63, there's a reason for that number. Someone who had 20 separate terminal windows open for example would be using at least 28 I believe, and with ssh logins, more, so that 63 number isn't really excessive I believe.

I'm not clear on the difference between /dev/tty/number and /dev/pts/number but I'd hold off until you're sure.
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Thanks for taking your time!



I followed systemd optimization guide, and they told me I should compile my kernel. I always wanted to try a minimal kernel anyway.

The result was just like you said, the difference is almost unoticeable. Now I'm back to Liquorix and even to init: with some readahead it still boots much faster than systemd.



I thought it could reduce some boot time by giving less work to udev. But I'm sorry, I thought Liquorix was optimized only for desktops running X.



That's better than I thought. I couldn't come up with anything after some googling. Thanks!



I don't know how many users feel the way I do, but I'd love if you could change it, or remove it at all. That was just my opinion anyway, don't worry!



There is indeed difference between /dev/tty* /dev/pts/*:
/dev/tty* is affected by the kernel config.
/dev/pts/* is created dinamically. I just tested it with CONFIG_NR_TTY_DEVICES=12 and opened 18 terminal windows: it created /dev/pts/18 with no problems.
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teresaejunior, oh, thanks for testing that.

How about ssh sessions? or remote X sessions or whatever?
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I have no way to test that actually..!
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Have you tried sshing back into the same computer you are using?
You can do that though it is generally useless to do so.
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No, but there is no interest in reducing that number of ttys. I actually thought nobody used more than 12, since most keyboards don't come with F13, etc., but there must be some way to access the other ones by some other means.
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"ALT+Left Arrow" and "ALT+Right Arrow" cycles through ttys when you are outside of X.
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That's great, I really didn't know about that, although I haven't really been using ttys lately, only when things go wrong.
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