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

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Keyboard merely plugged in greatly increases kernel boot time

Specs are here. I am using a K65 RGB. I am using the ckb-git package from the AUR to provide basic input functionality. With Keyboard and with driver: Startup finished in 3.100s (firmware) + ...
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0answers
90 views

New laptop - hub over-current condition

I bought a new laptop Lenovo B50-70 and I abe installed Linux Mint. In the syslog is long output og messages: .... hub 1-1:1.0: over-current condition on port 3 hub 2-0:1.0: over-current ...
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3answers
321 views

How did the Linux Kernel project track bugs in the Early Days?

We all know that Linus Torvalds created Git because of issues with Bitkeeper. What is not known (at least to me) is, how were issues/tickets/bugs tracked up until then? I tried but didn't get anything ...
6
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2answers
12k views

How to create an initrd image on OpenSuSE linux?

/usr/src/linux-3.2.1 # make install scripts/kconfig/conf --silentoldconfig Kconfig sh /usr/src/linux-3.2.1/arch/x86/boot/install.sh 3.2.1-12-desktop arch/x86/boot/bzImage \ System.map ...
3
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1answer
184 views

OOM Killer value always one less than set

I am trying to set the oom_adj value for the out of memory killer, and each time I do (regardless of the process) I get back exactly one less than I set (at least for positive integers. I haven't ...
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1answer
45 views

What is a Kernel Routine ?

In another answer I met a short overview of the sections of the man pages: commands for $-User system call, that means evoking a function from the Kernel library call, that means evoking a function ...
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1answer
19 views

can't find “buildkernel” target in FreeBSD source files

I'm trying to compile a FreeBSD 9.3 Kernel. in the docs it states that the commands make buildkernel and make installkernel must be run, However I can't find these two targets anywhere in the make ...
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46 views

How to get the Adaptec 1200A to work under Linux at UDMA/100 (instead of 66)

A while ago, I got myself a used Adaptec 1200A controller card to keep my onboard slots free for easier connect/disconnect of drives and now I am wondering why this card will only operate at UDMA 66. ...
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2answers
4k views

ulimit & rlimit in Linux, are they the same thing?

I see people use the terms ulimit & rlimit interchangeably, can I say they are referring to the same thing?
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2answers
7k views

Where to download Linux Kernel source code of a specific version?

Is there a resource to download a specific kernel version source? For example, I want to get 2.6.36.2 sources to compare with this package and see what changes were introduced?
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2answers
2k views

Capturing key input from events device and mapping it (toggle TouchPad key is unmapped)

I have a Lenovo IdeaPad Yoga 13 with Ubuntu 13.10 Installed. The device has a "Toggle TouchPad" button on the keyboard (F5). The keyboard's F* buttons are reversed (so to get F5, I need to press Fn + ...
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1answer
40 views

Find out which kernel source files were used when kernel was compiled

I am compiling the Linux kernel for my specific hardware and I only select the drivers/options which I really need. This is in contrast to a typical distribution kernel, where they compile almost ...
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1answer
124 views

/dev/input/event0 is missing in embedded linux

I'm working on a project and we are trying to make a touch-screen work using Qt with Tslib. We already made some previous prototypes and we managed to make them fully functional. But when creating a ...
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1answer
211 views

Compiling kernel but doesn't build kernel modules

I am trying to compile a linux-sunxi kernel for my Banana pi. Using this link: http://sunxi.org/Linux_Kernel#Compilation Unfortunately I am getting the following message at the bottom when I am ...
4
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1answer
69 views

git: show which files have changed between kernel 3.18.6 and 3.18.7

I have checked out linux kernel git repository git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git I know how to use git log, git show and similar commands to see ...
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1answer
88 views

Pfsense source code to build firewall

Pfsense is an open source Firewall based on openBSD kernel. Where can I find the code and how to modify it to build my firewall?
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2answers
89 views

MMU-less kernel?

I would like to try compile mmu-less kernel. From what I found in configuration there is no option for such a thing. Is it possible to be done?
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0answers
48 views

Compiling a loadable kernel module(Debian/Ubuntu)

This question is a follow up of this one. I am trying to compile the ELF loader as an individual LKM and use it as a standalone application(replacing the original module within the base kernel sounds ...
3
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1answer
121 views

Get kernel source: apt-get install vs apt-get source

I'm looking forward to download a Linux Kernel to get to know how to modify it and how to compile it. I am using Debian distribution and I'm interested in the Debian-modified Linux Kernel rather than ...
0
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1answer
85 views

How can I boot into Ubuntu with a linux kernel with an earlier version?

Part of the output of ls -ld /usr/src/linux-headers* on ubuntu 12.04 is: drwxr-xr-x 24 root root 4096 Jun 4 2013 /usr/src/linux-headers-3.2.0-45 drwxr-xr-x 7 root root 4096 Jun 4 2013 ...
4
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1answer
146 views

Can I limit the size of the linux file cache?

I am running 64-bit Xubuntu 14.04, linux version 3.8.0-25 with 8GB of RAM. I have a script (in MATLAB, for what it's worth) that loads a large number of data files (~23k) one at a time, for a total ...
3
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1answer
39 views

How do I completely remove a wireless interface (and re-add it)?

I'm trying to use a new usb wireless interface (atheros ar9271) and my onboard wireless (intel 6200) is interfering with it. The goal is for me to be able to turn the rf kill switch on (enabling ...
4
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2answers
2k 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)?
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3answers
10k views

How can I know which IRQ is responsible of high CPU usage

I've moved a server from one mainboard to another due a disk controller failure. Since then I've noticed that constantly a 25% of one of the cores goes always to IRQ however I haven't managed myself ...
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3answers
9k views

Why would the kernel drop packets?

I interrupted tcpdump with Ctrl+C and got this total summary: 579204 packets captured 579346 packets received by filter 142 packets dropped by kernel What are the "packets dropped by kernel"? Why ...
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0answers
179 views

Centos 7 boot up with custom kernel problem

I have installed centos 7 on virtualbox machine which has kernel-3.10.0-123.20.1.el7.x86_64. I am trying to build Linux kernel from kernel sources. I downloaded the kernel source files from: ...
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1answer
9k views

What does the 'i8042.nomux=1' kernel option do during booting of Ubuntu?

I have a laptop with a multi guesture touchpad. My touchpad never works in any Linux distro such as Ubuntu, Fedora, openSUSE, Linux Mint, Knoppix, Puppy, Slitaz and lots more. I have tried lots of ...
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0answers
2k views

SCTP support for Linux kernel 3.3.4-5.fc17.x86_64

I'm using Fedora 17 64-bit version, with Linux kernel version 3.3.4-5.fc17.x86_64. I installed lksctp using yum. sudo yum install lksctp-tools.x86_64 When I try to run sctp_status -H 127.0.0.1 ...
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0answers
18 views

Get static driver from kernel zImage

I have one kernel zImage inside that there is one static modules for touch panel So is it possible to get touch panel module from zImage because I have no kernel source Please guide me
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2answers
122 views

Generate major page faults

Is it possible to generate major page faults in the linux kernel at will? Can a program be written such that it is guaranteed to cause a major page fault on it's execution.
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1answer
2k views

Silent booting Linux from u-boot

For security reasons I have to boot Linux from u-boot with all output hidden (silently) until a password is entered. I've configured uBoot to do this correctly using the CONFIG_AUTOBOOT_KEYED macro ...
0
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1answer
72 views

setting (system-wide) CPU affinities for running processes on a Linux platform

I am conducting a kind of research in that I schedule multiple parallel applications (e.g., OpenMP/pthreaded applications) and execute the applications on specific (partitioned) cores on Linux-based ...
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32 views

Linux Networking Bootup script takes too long

I am working with a fork of a raspberry pi SoC. One of the modification is the use of AP6210 WiFi/Bluetooth chip. I am running Debian. During boot up, the following 3 startup scripts need to run in ...
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1answer
43 views

How to see kernel time variables without using adjtimex?

The man page for adjtimex says Anyone may print out the time variables, but only the superuser may change them. How do I see the value shown by adjtimex -p as the tick variable without using ...
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1answer
69 views

Recognizing GPT partition table created with different logical sector size

I have a 3TB drive which I have partitioned using GPT: $ sudo sgdisk -p /dev/sdg Disk /dev/sdg: 5860533168 sectors, 2.7 TiB Logical sector size: 512 bytes Disk identifier (GUID): ...
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63 views

How does the Linux kernel initialize console graphics?

Observation: I switch on a Linux box Boot loader displays its output on screen Boot starts with first output messages Screen goes blank, and never comes back on. Note: this is about the console, ...
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1answer
129 views

Kernel ATA Exception after resume from suspend to RAM

After resuming from suspend to RAM, my Arch Linux system freezes and becomes permanently unresponsive. However, I managed to pull the following kernel log: kernel: sas: Enter sas_scsi_recover_host ...
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1answer
41 views

NAS: 100% system (kernel) cpu usage

I have a single core NAS My Live Duo. It runs Debian lenny release. I found via htop utility that it constantly use 100% of red cpu without any noticeable process to eat it. Than I checked via iostat ...
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2answers
305 views

Library routines in linux kernel

In the linux kernel, there is a section "Library routines" with a snippet shown below: Library routines ---> <M> CRC-CCITT functions <M> CRC ITU-T V.41 functions <M> CRC7 ...
3
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1answer
6k views

How to get back from “testing” to “stable” - Kernel downgrade

currently I am having lot's of fun with apt-get - and the bad thing is, it was my own fault. I had enabled the testing packages in /etc/apt/sources.list to install a certain package. And I told my ...
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0answers
26 views

Linux Kernel Version >=3.14 Obliterates Wi-Fi Dongle!

I own a TP-LINK WN725N, and any linux distro with the kernel version before 3.14 works fine, but past 3.14, the dongle cannot hold a speed of over 10 kb/s for more than 10 seconds. Reconnecting solves ...
35
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1answer
16k views

Kernel inotify watch limit reached

I'm currently facing a problem on a linux box where as root I have commands returning error because inotify watch limit has been reached. # tail -f /var/log/messages [...] tail: cannot watch ...
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0answers
142 views

Corrupt LVM metadata header after kernel update

I'm running Debian Wheezy (Linux wheezy3.2.0-4-amd64 #1 SMP Debian 3.2.63-2+deb7u1 x86_64 GNU/Linux) as an encrypted LVM with hardware raid 1 (Adaptec 6405E) on a supermicro server. I was encounting ...
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2answers
3k 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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2answers
102 views

Log message “Disabling IRQ”: what does it mean?

This message appears in my dropdown terminal at seemingly random times when no processes is running in that terminal: andreas@debianator:~$ Message from syslogd@debianator at Feb 24 18:57:58 ... ...
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41 views

Do dracut handles boot parameters mentioned in dracut.cmdline (7)

If I understand correctly, in boot time the kernel will mount initramfs and then calls /sbin/init from it(which is a symbolic link to /lib/systemd/systemd on Fedora/RHEL systems) and dracut itself ...
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4answers
1k views

Why some operating systems event handling is written in asm instead of c?

My question is why nowadays some operating system event handling is still written in assembly language instead of a higher level language such as C, when the kernel itself is written mostly in C?
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1answer
475 views

Can the 25 years of development of the Linux kernel be qualified or abstracted in layman's terms? [closed]

The Linux kernel is almost 25 years old. If I had to come up with the short version on the development history of the Linux kernel since 1991(its inception date), and in partcular since 1994 (1.0.0) ...
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0answers
17 views

insert module to kernel

I installed latest version of IPCOP, I've the correct module of my wireless card (htc_9271.fw): put it to /lib/firmware/ there is not any insmod/rmmod but only modprobe: modprobe htc_9271 FATAL: ...
4
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1answer
114 views

RTC time synchronization not working (CONFIG_RTC_SYSTOHC)

I have the option CONFIG_RTC_SYSTOHC enabled in my kernel: Device Drivers ---> [*] Real Time Clock ---> [*] Set the RTC time based on NTP synchronization The help says: ...