Linux Kernel Fastboot [pdf]

Post by icedchai » Mon, Sep 16, 2019, 8:07 PM UTC

bt848 wrote: post #110

icedchai wrote: post #17

Earlier quoted context omitted.

I think Sun must've tried and failed. Boot times on late 90's era Solaris/Sparc systems were atrocious compared to Linux/x86 systems of the day.

Just to underscore this, here's a video of some guy booting an Ultra 45, the last workstation Sun ever made. It takes 30s just to go from power-on to firmware initialized and another minute and a half to start Solaris. Older equipment such as a SPARCStation 20 would take much longer. https://www.youtube.com/watch?v=BjshAKzhxTE

Post by ComputerGuru » Mon, Sep 16, 2019, 11:01 PM UTC

wtallis wrote: post #61

ComputerGuru wrote: post #36

Earlier quoted context omitted.

SATA controller firmware has a hard-coded “drive predelay” that waits before enumerating attached devices, a relic from the days long before SSDs. Even when an option to set a custom amount is available in the BIOS, it is in addition to and not instead of, as there’s no bus master to tell it all attached disks have init and the controller may speak to them. It wouldn’t necessarily have to be done synchronously up fro…

The delay in question is in initializing the Linux driver, not in the system firmware scanning for bootable devices before running Linux. The Linux driver may be taking a while for similar reasons as the firmware delay you describe. The hard drive predelay is also not as obsolete as you may think; I've encountered high-capacity SATA SSDs that take a surprisingly long time to come up after being hotplugged, to the poi…

Post by Filligree » Tue, Sep 17, 2019, 1:07 AM UTC

cerberusss wrote: post #105

Filligree wrote: post #103

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What about it? It doesn't seem to be enormously useful, given I can do so much better on my own. I got the laptop to have well-supported hardware, not because I was expecting a lot of help from Dell.

Is that all there is to it, just well supported hardware? Dell didn't configure Redhat in any way, to make better use of the hardware? I'm thinking trackpad, sleep and hibernation, graphics etc.?

Post by big_chungus » Tue, Sep 17, 2019, 1:51 AM UTC

ComputerGuru wrote: post #112

mises wrote: post #102

Earlier quoted context omitted.

Clear kernel performed better in every single test run by phoronix, except one (because it has retpoline and others did not). https://www.phoronix.com/scan.php?page=article&item=arch-ant...

I think you misunderstood. I was saying in a typical stack, time from POST to desktop is significantly overshadowed by userland bloat, not that Clear kernel is not worth the optimization.

Post by tvst » Tue, Sep 17, 2019, 5:38 AM UTC

zbjornson wrote: post #59

tvst wrote: post #40

Earlier quoted context omitted.

Clear Linux is blazing fast (compiled with Intel compilers), and supposedly has a strong security model -- but it also has an extremely limited package selection. To the point that it's just not usable for me. Also, its package manager forces you to install "bundles" of somewhat related packages rather than just the specific packages you want and their deps. Maybe I'm missing something, but I find this very odd.

> compiled with Intel compilers This is a common misconception. It's not built with ICC, it's built with GCC (and some parts maybe with Clang). When did you try Clear? They have about 6200 packages now, but I'm not sure if that's still "limited" in relative terms.