X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=docs%2Fudev_vs_devfs;h=fbf757d437b2b58c4f5de518d44ff235814368cd;hp=5a46231c1fa12cb39dd789627569a23a1289bd2a;hb=03b24b71e05d116c592b08281f8a5f0dadf6d3c7;hpb=3310f9d0e8a585c4b96d558a34b06b47699586b1 diff --git a/docs/udev_vs_devfs b/docs/udev_vs_devfs index 5a46231c1..fbf757d43 100644 --- a/docs/udev_vs_devfs +++ b/docs/udev_vs_devfs @@ -13,7 +13,7 @@ Executive summary for those too lazy to read this whole thing: will be gladly ignored. -First off, some background. For a description of udev, and what it's +First off, some background. For a description of udev, and what its original design goals were, please see the OLS 2003 paper on udev, available at: @@ -26,7 +26,7 @@ directory. In that OLS paper, I described the current situation of a static /dev and the current problems that a number of people have with it. I also detailed how devfs tries to solve a number of these problems. In -hindsight, I should have never mentioned the word, devfs, when talking +hindsight, I should have never mentioned the word "devfs" when talking about udev. I did so only because it seemed like a good place to start with. Most people understood what devfs is, and what it does. To compare udev against it, showing how udev was more powerful, and a more @@ -90,7 +90,7 @@ And now for udev: to name devices in a persistent manner. More on that below. 4) udev emits D-BUS messages so that any other userspace program (like HAL) can listen to see what devices are created or removed. - It also allows userspace programs to query it's database to see + It also allows userspace programs to query its database to see what devices are present and what they are currently named as (providing a pointer into the sysfs tree for that specific device node.) @@ -108,7 +108,9 @@ Nice, 7 out of 7 for udev. Makes you think the problems and constraints were picked by a udev developer, right? No, the problems and constraints are ones I've seen over the years and so udev, along with the kernel driver model and sysfs, were created to solve these real -problems. +problems. I also have had the luxury to see the problems that the +current devfs implementation has, and have taken the time to work out +something that does not have those same problems. So by just looking at the above descriptions, everyone should instantly realize that udev is far better than devfs and start helping out udev @@ -121,8 +123,8 @@ everything that devfs currently does, in about 6Kb of userspace code: Yes, that's right, 6Kb. So, you are asking, why are you still working on udev if it did everything devfs did back in May 2003? That's because just managing static device nodes based on what the kernel calls the -devices is _not_ the primary goal of udev. It's just a tiny side affect -of it's primary goal, the ability to never worry about major/minor +devices is _not_ the primary goal of udev. It's just a tiny side effect +of its primary goal, the ability to never worry about major/minor number assignments and provide the ability to achieve persistent device names if wanted. @@ -130,7 +132,7 @@ All the people wanting to bring up the udev vs. devfs argument go back and read the previous paragraph. Yes, all Gentoo users who keep filling up my inbox with smoking emails, I mean you. -So, how well does udev solve it's goals: +So, how well does udev solve its goals: Prevent users from ever worrying about major/minor numbers And here you were, not knowing you ever needed to worry about major/minor numbers in the first place, right? Ah, I see you