Everything about UNIX kernels: development, configuration, compilation, design, etc.

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SIOCSIFADDR: File exists after upgrading kernel

Since upgrading my (Gentoo) kernel from 2.6.38 to 3.3.8 (via oldconfig), I can't get the network on eth0 up anymore. It reports "SIOCSIFADDR: File exists" with a number of other SIOCSIF* errors that ...
3
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1answer
424 views

How to submit a Linux module upstream?

I've written a useful kernel module for a specific fan controller that I want to submit upstream. Where can I find an address to submit my module? Do I need it make GPL or can I use a less ...
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2answers
2k views

An oom killer thats baffling me

I am not able to understand why would kernel issue this oom killer when I see enough memory is available: Also why are there so many kernel cache pages allocated? I say enough memory is available ...
6
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4answers
251 views

Why are Linux installs bigger than I've read? Some beginner questions

I've read in different textbooks that say Linux is light-weight(e.g. It could fit on a 1.4MB floppy). So why is the download from the Ubuntu or Fedora CD sized or larger? Do the device drivers extend ...
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3answers
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Does /init (or /linuxrc) script creates temporary device nodes in /dev?

Considering that GRUB executes following lines: kernel /vmlinuz root=/dev/sda1 ro initrd /initrd On boot, how does the Linux kernel finds out about /dev/sda1 device node? I know that initrd/...
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4answers
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Cannot create “Hello World” module (and NVIDIA, and VirtualBox)

First off, the details. BEFORE: kernel: 3.2.0-2-amd64, nvidia driver: 295.59 AFTER: kernel: 3.2.0-3-amd64, nvidia driver: 302.17-3 My Debian wheezy is kept recent at all times. Actually, doing ...
5
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1answer
6k views

How to know which firmware is loaded by kernel?

I have an Intel wireless card driven by iwlwifi, and I can see the following message in dmesg: iwlwifi 0000:03:00.0: loaded firmware version 17.168.5.3 build 42301 But how do I know which firmware ...
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1answer
714 views

Is it safe to use customized CFLAGS for linux kernel, e.g mmx sse instructions

Is it safe to use customized CFLAGS while compiling linux kernel, e.g enable SSE, MMX instructions, is that a problem ?
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2answers
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Can I detect if my custom made kernel was built with module support?

I have been provided with a vendor supplied minimal linux installation. From an answer to a previous question I discovered that it is possible to build a kernel with or without module support. I have ...
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653 views

Linux thin station

I have this pc that I just installed and set it up as Linux thin station. I did all the formatting procedures and copying of image to the HD. When I boot it up, I get these, which I think are driver ...
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0answers
120 views

How to deal with closed source modules when configuring a new kernel build

I found this command very useful: make localmodconfig However, having some closed source drivers/modules ends up being a problem because this command can't find an appropriate way of including the ...
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2answers
406 views

yum is asking the kernel version which is already there

I have a server with centos 5.3 x86_64 on it. I am trying to install some asterisk modules on this server using yum. So yum asked me to upgrade my kernel to "kernel-2.6.18-308.11.1.el5" Then i have ...
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2answers
526 views

Do Solaris 10 and 11 still use slab allocation for their kernel memory allocator

If not, what do they use. Please provide a source.
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0answers
246 views

How to find where driver.mod.c links to?

I'm trying to port the webcam composite gadget from kernel 2.6.37 to 2.6.32. I don't have a choice on this since I depend on other drivers and a SDK which only compile for this version. My train of ...
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2answers
2k views

Does Linux kernel 3.x use the CFS process scheduler?

Does the latest version of the Linux kernel (3.x) still use the Completely Fair Scheduler (CFS) for process scheduling which was introduced in 2.6.x ? If it doesn't, which one does it use, and how ...
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1answer
2k views

How can I use netconsole to help solve a kernel panic?

When I try to use a raid as root, my system panics. I want to read the kernel output right before the panic, but can't scroll up. After Googling a bit, I wanted to try netconsole. but I get no output ...
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2answers
310 views

How am I supposed to keep up with kernels as a developer?

I'm developing for a specific TI ARM processor with custom drivers that made it to the kernel. I'm trying to migrate from 2.6.32 to 2.6.37, but the structure changed so much I will have weeks of work ...
3
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1answer
1k views

High memory (user space) and highmem (kernel space)

Each process has 2 memory area: User space (high memory) and kernel space (low memmory). In the kernel space, are the first 896 MB used for mapping kernel code (not fully 1 GB)? This means, when a ...
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0answers
712 views

Can I apply real time Linux kernel patch on Android kernel?

I would like to apply real time patch on the Android kernel (given I've found Kernel patch for corresponding Kernel version). Is it possible or should I create a patch specifically for the purpose of ...
5
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1answer
755 views

When should I keep debugging symbols in kernel modules?

When installing kernel modules, I have the option to strip out debugging symbols using INSTALL_MOD_STRIP=1. This saves significant disk space. Does it also save memory? Why should one keep the ...
6
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2answers
3k views

Booting a newly compiled linux kernel

I have started reading the book Essential Linux Device Drivers. I am following the process for compiling and booting into a new kernel. However I am unable to boot into the newly compiled kernel - I ...
2
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1answer
421 views

Automatically update a Debian system

I want to automatically update a Debian system (actually Debian Wheezy on Raspberry Pi, though that shouldn't make much a difference). I've already seen that there is cron-apt, probably a good choice, ...
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1answer
6k views

How do I convert a kernel .config file from 32-bit to 64-bit?

At this page you can download a configuration file that lets you target a particular notebook architecture during the compilation of a new 32-bit Linux kernel. I need a 64 bit version. What do I ...
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1answer
4k views

How can I generate /proc/vmcore?

I want to practice with makedumpfile. However, it needs /proc/vmcore which is the memory image of the currently running kernel. Also, reading the man page of makedumpfile, we also need 2 kernels: ...
2
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1answer
174 views

Choose kernel for specific hardware

I have old system with an AMD Athlon 1,2 GHz processor and [SiS] 65x/M650/740 graphics (output from lspci). Recently I discovered on a german ubuntu page that since version 10.10 some older ...
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1answer
2k views

Is Native Language Support (NLS) kernel support still necessary?

Does ext4 / cifs system need kernel NLS support ? I'm not sure if it's being handled by user-space program (decoding / encoding) ?
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2answers
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How to know if a network interface is tap, tun, bridge or physical?

As far as i know, there are 4 main types of network interfaces in linux: tun, tap, bridge and physical. When i'm doing sys admin on machines running KVM, i usually come accross tap, bridge and ...
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1answer
394 views

Edit the .config file when en/disabling a particular option like CONFIG_CPU_FREQ?

From here: http://www.xenomai.org/index.php/FAQs#Which_kernel_settings_should_be_avoided.3F Which kernel settings should be avoided? Note that Xenomai will warn you about known invalid ...
6
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1answer
3k views

WARNING: modpost: Found 10 section mismatch(es)

Is this error message something that I should be worried about? linux-y3pi:/usr/src/linux-2.6.38.8 # make modules scripts/kconfig/conf --silentoldconfig Kconfig CHK include/linux/version.h ...
4
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1answer
2k views

How to know whether the Linux driver for the real-time network device was built into the kernel?

From here: http://www.xenomai.org/index.php/RTnet:Installation_%26_Testing#Debugging_RTnet The Linux driver for the real-time network device was built into the kernel and blocks the hardware. ...
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1answer
327 views

install 2.6.32.59 on squeeze

I'm suffering from a kernel bug in a production environment. The problem isn't causing a complete outage, but it's degrading service. These are soft lockups. I'd like to try a newer kernel, ...
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1answer
859 views

Is it necessary to enable CONFIG_USB_OHCI_HCD , when there's only USB 2.0 ports

Is it necessary to enable CONFIG_USB_OHCI_HCD on a system that has USB 2.0 port only ? I'm not sure those devices present , e.g bluetooth , camera use that driver ? Bus 001 Device 001: ID 1d6b:0002 ...
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1answer
427 views

Where is CONFIG_APM in kernel - 2.6.38.8

From here: http://www.xenomai.org/documentation/xenomai-2.6/TROUBLESHOOTING Q: Which CONFIG_* items are latency killers, and should be avoided ? ... APM: The APM model assigns power management ...
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1answer
119 views

ACPI (Advanced Configuration And Power Configuration) not present on 2.6.38.8?

I need to disable some parts in ACPI, but it is simply not present in kernel 2.6.38.8 (downloaded as a tar from net)? I can see the option in kernel 2.6.34-12 (default on OpenSuse 11.3), but not in ...
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2answers
976 views

buildroot/busybox: launch bootchartd on startup

I built a custom linux image using buildroot and busybox. To speed up the boot process I'd like to use bootchartd (built-in version of busybox) to profile the process. However bootchartd is not ...
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1answer
261 views

how to enable sound support in linux kernel without recompile?

I have recently compiled linux kernel 3.2. But at time of compiling in make menuconfig, I had disabled sound support. Now, I want to enable it without recompile it. I don't want to use stock kernel ...
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3answers
667 views

Why does Linux on sparc64 architecture use 32-bit pointers in user-space and 64-bit pointers in kernel-space?

What are the advantages of deviating from the norm; that is 64-bit pointers in both user and kernel space for a 64-bit architecture? Reference: http://lwn.net/images/pdf/LDD3/ch11.pdf (Page 2)
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0answers
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Qemu doesn't boot kernel after “Uncompressing Linux… done, booting the kernel. ”

I've compiled qemu for s5pc110 (it's from http://gitorious.org/samsung-linux-platform/qemu, somebody had added support for s5pc110), version 0.12. But when I load the kernel: qemu-system-arm -M ...
98
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6answers
159k views

How to reload udev rules without reboot?

How should one reload udev rules, so that newly created one can function? I'm running Arch Linux, and I don't have a udevstart command here. Also checked /etc/rc.d, no udev service there.
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3answers
5k views

Why don't you need to update drivers? (Or do you?)

In my life I've not once updated drivers on any of my Linux systems, though they have all been desktops. A friend was asking me why one does not need to update Linux drivers and I found myself unable ...
5
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1answer
870 views

Needs help on setting up kernel keyboard mapping

I already got the keycode from kernel, but acpi_listen won't recognize it in Arch Linux: # /usr/lib/udev/keymap -i /dev/input/by-path/platform-thinkpad_acpi-event Press ESC to finish, or Control-C if ...
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2answers
107 views

linux with 3.2.x kernel [closed]

Is there a major Linux distribution that uses 3.2.x kernel?
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2answers
3k views

vmlinuz and initrd not found after building the kernel?

After configuring and building the kernel using make, why don't I have vmlinuz-<version>-default.img and initrd-<version>.img, but only got a huge vmlinux binary (~150MB)?
2
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1answer
588 views

Which edac module should I enable here?

I got a Intel(R) Core(TM) i5-2450M CPU @ 2.50GHz CPU here , not sure which module should be enabled for EDAC: Chipset: Inter Coporation 6 Series/C2000 , driver in use: i801_smbus
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2answers
3k views

How do I build the iptables kernel module for a loaded kernel?

I've built a kernel with loadable module support for various reasons, one of them the possibility to compile modules and load them without rebooting. This is supposed to be useful when I need a module ...
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1answer
3k views

Can the Linux kernel be compiled on Mac OS X 10.6.8?

I have a Macbook Pro and I want to build the Linux Kernel. Can I build 3.3.6 on my Mac? How?
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1answer
2k views

Do I have to list modules in both `/etc/mkinitcpio.conf` and `/etc/rc.conf`?

I've added few modules into mkinitcpio.conf. Are they automatically loaded at kernel boot or with udev if I don't specify them in modules list in rc.conf?
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2answers
4k views

VirtualBox guest: 16 CPUs detected but only 1 online

I am running VirtualBox (using the Qiime image http://qiime.org/install/virtual_box.html) The physical hardware is a 32 core machine. The virtual machine in VirtualBox has been given 16 cores. When ...
4
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1answer
213 views

What does CONFIG_IA32_AOUT do actually?

I'm running a 64bit kernel, already have CONFIG_IA32_EMULATION set, so do I still need CONFIG_IA32_AOUT enabled? From the help in menuconfig, I don't quite get it.
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3answers
17k views

How can I reserve a block of memory from the Linux kernel?

I have a device that needs a block of memory that is reserved solely for it, without the OS intervening. Is there any way to tell BIOS or the OS that a block of memory is reserved, and it must not ...