While doing

make menuconfig

I see, that I am pointing directly which driver or component should be compiled "as module". This makes me think, that the names of modules to use by kernel are hardcoded into the kernel.

But recently I have installed infiniband drivers and installer created /lib/modules/<name>/kernel/drivers/ infiniband directory with many *.ko files.

Did installer recompiled my kernel? Or it is possible for kernel to load modules which names are not hardcoded into it?

What distro are you using? For me, the file /etc/modules tells the kernel which modules it wants loading at boot.

I am using Fedora 9, and /etc/modules is absent here.

But does distro affects modules stuff really?

I was thinking, that kernel and modules as a part of it, are independent of distribution.

What command

make modules_instal

does while compiling kernel?

Doesn't it copies *.ko files from kernel source to systemwide place? If so, then how it is possible for this kernel to work if I have downloaded it form kernel.org site which is unrelated with distribution?

The kernel modules for a kernel are located under /lib/modules/$(uname -r)

Some of the modules are copied to the initrd file. Others are loaded later. Look in your /etc/modprobe.conf, /etc/modprobe.d/* & /etc/modprobe.conf.local files.

Okay, but what is the algorithm? Who decides, what file to load and what file to read?

Ok, you are on Fedora 9. The configuration file is /etc/modprobe.conf or if the directory /etc/modprobe.d exists, then the entries in that directory.

A few modules are compiled directly into the kernel. Modules that are needed at boot time are loaded by GRUB from initrd.

I don't think the OP is asking about that. Those that you all mention are just userland scripts.

He might be more concerned about the mechanism that triggers the mechanism and how a kernel knows that a given module is the one that should handle a given device. And I guess that this post could get a better answer in the kernel subsection of the forum, where someone with a real knowledge about the issue will possibly be able to give a much more accurate response than I could give him.

That's why I am reporting this to be moved to a more convenient section.

Modules have to be loaded into memory - they then are effectively extensions to the kernel itself. When you installed the drivers (using rpm or yum presumably), it will have updated the modprobe.conf or modprobe.d as mentioned above. These are used by the (distro specific) init scripts at boot time to determine what modules should be loaded. A module can in need be loaded at any other time - it's possible for the install process to do this for you as well.
See "man modprobe" and "man modprobe.conf".

As for the later question, modules register their interest(s) with the kernel- it determines when they get control.

Does kernel tries to boot a driver for each specific graphics card during boot?

If "yes", then where I can find a dozens of lines, prescribing it to do that?

Or kernel knows my card model beforehand?

If "yes", then what will happen if I remove graphics card?

Moved: This thread is more suitable in <Linux - kernel> and has been moved accordingly to help your thread/question get the exposure it deserves.

Hi am trying to install tcp probe tool

1) Downloaded new kernel.
2) Installed new kernel with tcp probe enabled in Networking category.
3) Restarted the laptop on new kernel.
4) But I dont see tcp_probe getting installed.
5) Giving following error when I try to do modprobe
FATAL: Module tcp_probe not found.

Let me know how to install tcp_probe

After changing the MakeFile of the Kernel it got worked

Generally speaking, the mechanism which is used to handle device-insertion is called hotplug.

When a USB device is attached or removed, the kernel has the means of broadcasting a notification to "anyone who might be listening," and that "anyone" will be the hotplug daemon. Using various information tables, hotplug figures out if any drivers need to be loaded.

It's a bit more complicated than that, but there's the idea.