Arch Linux

jeff story

Member

Registered: 2009-05-31

Posts: 237

Website

Patches, Upstream, Downstream Explanation Please

I'm trying to get a grasp on what a Linux distro is and entails behind the scenes. I believe I have a vague and possibly incorrect idea of the terms, patches, upstream and downstream. What else am I leaving out and please explain.

I'll start with the following examples. I have read that Ubuntu is at one end of a scale and Slackware is at the other.

Ubuntu has a heavily patched kernel and packages. Slackware is "virgin?" as in unmodified kernel and packages.

Are all kernel patches for security issues, file system and hardware support prior to getting officially implemented into the new kernel?

Do kernel patches necessitate package patches?

Is the following correct?  unpatched = simpler, cleaner, stability, standards compliant  -vs-  heavily patched = opposite of the proceeding

I really have no idea of what the terms upstream and downstream are and how they apply to the big picture other than a wild guess.

Last edited by jeff story (2010-10-24 20:32:27)

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karol

Archivist

Registered: 2009-05-06

Posts: 25,440

Re: Patches, Upstream, Downstream Explanation Please

Upstream means the developer, the person(s) who writes the source code. Downstream means the person who maintains the binary package for some distro.

Let's say I'm a dev and I wrote a nifty tool I'd like to share. I work hard to make it work on many OSes: Linux, BSD, OSX, Solaris, maybe even Windows.
You are a maintainer for this app for the Arch Linux distro: you create the package which follows the rules set by the Arch overlords: best practices, our internal standards etc.

Do kernel patches necessitate package patches?

Not, maybe in some cases.

Is the following correct?  unpatched = simpler, cleaner, stability, standards compliant  -vs-  heavily patched = opposite of the proceeding

Sometimes a patched app / kernel means it's working the way you think it should / on some kind of exotic hardware, while the vanilla version does not.

Last edited by karol (2010-10-24 20:55:11)

dolby

Member

From: 1992

Registered: 2006-08-08

Posts: 1,581

Re: Patches, Upstream, Downstream Explanation Please

Applying patches, let alone tons of them, essentially means that you are forking the application downstream (in distro level) and you have to maintain out-of-tree (upstream) code.
Having said that, in most cases, distributions with limited human resources, like Arch, grab such patches from distributiions like Fedora or Ubuntu which can afford maintaining such pieces of code.

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