Linux boot time reduced by 0.035 seconds thanks to a one-line kernel patch — aligning the slab in the ACPI code makes Linux boot faster

News
By
published

This kernel patch will shave off a millisecond here and a millisecond there.

Linux logo in front of clocks
(Image credit: Unsplash)

Linux systems already boot relatively fast, but it's never fast enough. So, when Linux engineer Colin Ian King (via Phoronix) discovered that aligning the slab in the ACPI code would make Linux boot faster, it was considered a win for the system.

According to King, "Enabling SLAB_HWCACHE_ALIGN for the ACPI object caches improves boot speed in the ACPICA core for object allocation and free'ing especially in the AML parsing and execution phases in boot. Testing with 100 boots shows an average boot saving in acpi_init of ~35000 usecs compared to the unaligned version. Most of the ACPI objects being allocated and free'd are of very short life times in the critical paths for parsing and execution, so the extra memory used for alignment isn't too onerous."

The 0.035-faster boot time might mean nothing for most users, especially as people won't even feel a one-second change in loading times. But with Linux being an open-source system, many people with free time have been working on improving the OS, no matter how small. It has received multiple optimizations since the glory days of the netbook.

This slight decrease in boot times will have a more significant impact on data centers, many of which run on open-source Linux systems. This potentially minimizes downtime in servers that require 24/7 uptime and a 99.99% availability. The slight change could also affect millions of users, given the ubiquity of the operating system in many backend systems.

For example, 96.3% of the top 1,000,000 web servers use Linux, and over 460 of the top 500 supercomputers are powered by the operating system. IoT devices also prefer Linux, with a reported market share of 68% of all IoT devices in the wild. It's also used as the primary OS of 70% of the web servers globally.

Although the average user is only familiar with Android, iOS, Windows, or macOS, these numbers show how much of our modern world is driven by this open-source operating system and its derivatives. Even though 0.035 might seem insignificant, if you multiply that by the billions of Linux devices, you're potentially looking at days, months, and even years of operating hours saved.

Jowi Morales
Jowi Morales
Contributing Writer

Jowi Morales is a tech enthusiast with years of experience working in the industry. He’s been writing with several tech publications since 2021, where he’s been interested in tech hardware and consumer electronics.

8 Comments Comment from the forums
  • salgado18
    Nice. Still waiting for those devs who will improve desktop usability so it becomes more popular, but I don't oppose a small speed boost.
    Reply
  • kiniku
    As a diehard Windows gamer, I tried to make a transition to Linux. I exploit virtually every available Windows feature to make things easier for me. And again, I am a gamer, which is still not Linux's strong suit. But my last time trying this was like over 10 years ago, so I wanted to try again. I did a considerable amount of research trying to find the best "gaming friendly" distribution.
    All said and done, to get Linux even close to my acceptable baseline still comes with too many sacrifices to make it worth it. And I have no interest in dual booting, maintaining two separate OSs. But don't get me wrong, Linux is awesome! It's rock solid as a desktop OS. I like how it seems to do things automatically that Windows has to be "told" to. Linux is fast. But support for it can be hit or miss at times. And often even supported features/software etc. can be a research nightmare to get it to work properly. But if you are a tinkerer, and your need for gaming compatibility and development is not high like mine, Linux is fun!
    Reply
  • TJ Hooker
    salgado18 said:
    Nice. Still waiting for those devs who will improve desktop usability so it becomes more popular, but I don't oppose a small speed boost.
    Have you tried Linux recently, a user-friendly distro, like Ubuntu or similar? For basic desktop usability I don't really know what would be missing, unless there are specific Windows-only applications you need (which obviously isn't something Linux devs could help with).

    Even for gaming, in my experience if you use Steam then (nearly) everything just works as it would on Windows. It'll transparently handle setting up the Proton compatibility layer in the background, if required. That being said I don't really play brand new AAA games, or competitive games that have invasive anti-cheat mechanisms. Maybe those are still probablematic.
    Reply
  • GeorgeLY
    kiniku said:
    As a diehard Windows gamer, I tried to make a transition to Linux. I exploit virtually every available Windows feature to make things easier for me. And again, I am a gamer, which is still not Linux's strong suit. But my last time trying this was like over 10 years ago, so I wanted to try again. I did a considerable amount of research trying to find the best "gaming friendly" distribution.
    All said and done, to get Linux even close to my acceptable baseline still comes with too many sacrifices to make it worth it. And I have no interest in dual booting, maintaining two separate OSs. But don't get me wrong, Linux is awesome! It's rock solid as a desktop OS. I like how it seems to do things automatically that Windows has to be "told" to. Linux is fast. But support for it can be hit or miss at times. And often even supported features/software etc. can be a research nightmare to get it to work properly. But if you are a tinkerer, and your need for gaming compatibility and development is not high like mine, Linux is fun!
    Depends of what you're playing - most (though unfortunately not all) older games work better in Linux that in Windows. Quite a few modern ones work very well too, the major exception being games with anti-cheat technologies, but personally I would not install them on Windows as well as they integrate with the kernel (a big no-no if you want your computer for anything besides gaming).

    PS There are even aggregators, such as Lutris that make installation of Windows games easier.
    PPS I bought quite a few old games from GOG, that people have tons of problems with, but the problems are limited to Windows. Modern games that work perform better in Linux also.
    PPPS You need some minor knowledge of Linux to understand what you need to do in some cases (i.e. install i386 graphics libraries on Ubuntu).
    Reply
  • mitch074
    salgado18 said:
    Nice. Still waiting for those devs who will improve desktop usability so it becomes more popular, but I don't oppose a small speed boost.
    Have you tried more recent desktops ? They are not exactly unusable...
    Also, you don't have to navigate between crapware and ads to reach your applications shortcuts.
    It's not MacOS friendly yet, but it's much better than Windows 10 > 1709 or Win11...
    Reply
  • mitch074
    kiniku said:
    As a diehard Windows gamer, I tried to make a transition to Linux. I exploit virtually every available Windows feature to make things easier for me. And again, I am a gamer, which is still not Linux's strong suit. But my last time trying this was like over 10 years ago, so I wanted to try again. I did a considerable amount of research trying to find the best "gaming friendly" distribution.
    All said and done, to get Linux even close to my acceptable baseline still comes with too many sacrifices to make it worth it. And I have no interest in dual booting, maintaining two separate OSs. But don't get me wrong, Linux is awesome! It's rock solid as a desktop OS. I like how it seems to do things automatically that Windows has to be "told" to. Linux is fast. But support for it can be hit or miss at times. And often even supported features/software etc. can be a research nightmare to get it to work properly. But if you are a tinkerer, and your need for gaming compatibility and development is not high like mine, Linux is fun!
    A few years ago, I made a demo to a colleague at work : building a PC from scratch using AMD hardware, installing an OS and running a Steam game (Doom 2016 demo). We have a fast fiber at work, so download times were rather short.
    OS was Ubuntu 22.04 LTS, lite install (no app, only Firefox).
    It took 25 minutes from the moment I powered the system up to install the OS to the moment I had Steam installed, all system updates done, the game downloaded and running in OpenGL and Vulkan beautifully.
    If your requirements are "all my Xbox/Epic games must run", it's very hard. If like me most of your games are on Steam, it's very very VERY easy. Activision Blizzard is touche and go - it depends on wherher the Lutrix script to install the Blizzard app is up to date.

    Provided you're not running NVIDIA - their drivers installer breaks all the time - doing a gaming machine on Linux is very easy. As for development... No question asked, best OS ever.
    Reply
  • salgado18
    TJ Hooker said:
    Have you tried Linux recently, a user-friendly distro, like Ubuntu or similar? For basic desktop usability I don't really know what would be missing, unless there are specific Windows-only applications you need (which obviously isn't something Linux devs could help with).

    Even for gaming, in my experience if you use Steam then (nearly) everything just works as it would on Windows. It'll transparently handle setting up the Proton compatibility layer in the background, if required. That being said I don't really play brand new AAA games, or competitive games that have invasive anti-cheat mechanisms. Maybe those are still probablematic.

    mitch074 said:
    Have you tried more recent desktops ? They are not exactly unusable...
    Also, you don't have to navigate between crapware and ads to reach your applications shortcuts.
    It's not MacOS friendly yet, but it's much better than Windows 10 > 1709 or Win11...
    I work with Ubuntu 8h a day, and I also play one Windows game using Proton. And I think Linux is pretty usable, if you know what you're doing.

    But Ubuntu is way behind Windows and Mac OS in native functionality, some issues are hard to solve, the terminal will be needed sooner or later even for trivial stuff, and some basic stuff is nearly impossible to do (try using a token certificate to sign a document in both; in Windows it's plug and play, I still haven't solved it in Ubuntu).

    I'll still migrate my home PC fully to Ubuntu, as I don't trust Microsoft anymore, and I can overcome these limitations to make it my main OS. But that is hardly acceptable for the average user.

    My point is: Linux needs a lot more care from devs to reach a wider user base, not only tech enthusiasts but regular people.

    (Last comment: open a file explorer window, and click on the address bar. Does it edit the path as a user would expect, or does it do something else incomprehensible for 2024?)
    Reply
  • mitch074
    salgado18 said:
    I work with Ubuntu 8h a day, and I also play one Windows game using Proton. And I think Linux is pretty usable, if you know what you're doing.

    But Ubuntu is way behind Windows and Mac OS in native functionality, some issues are hard to solve, the terminal will be needed sooner or later even for trivial stuff, and some basic stuff is nearly impossible to do (try using a token certificate to sign a document in both; in Windows it's plug and play, I still haven't solved it in Ubuntu).

    I'll still migrate my home PC fully to Ubuntu, as I don't trust Microsoft anymore, and I can overcome these limitations to make it my main OS. But that is hardly acceptable for the average user.

    My point is: Linux needs a lot more care from devs to reach a wider user base, not only tech enthusiasts but regular people.

    (Last comment: open a file explorer window, and click on the address bar. Does it edit the path as a user would expect, or does it do something else incomprehensible for 2024?)
    You shouldn't use Gnome as a desktop then - that's a Bad Windows reflex, to think that what you get is all you can get. I wouldn't be surprised if you found better usability from KDE.
    Reply