The kernel of operating systems popularly known as Linux, or sometimes GNU/Linux.

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Some questions compiling linux kernel with make-kpkg

I'm doing my first steps compiling the linux kernel and adding a new system call. I've managed to do it, but I still have some questions. For this task, I has set up a Virtual Machine guesting debian ...
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2answers
1k views

What does a niceness value of (-) mean?

According to the man page, and wikipedia; nice ranges from -20 to 20. Yet when I run the following command, I find some processes have a non numerical value such as (-). See the sixth column from ...
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1answer
114 views

How to select which OS kernel to upgrade when multiple OS'es are installed?

I am trying to upgrade my kernel on a machine with multiple OS'es. I have a Red Hawk OS (a real-time Red Hat variant) and Red Hat installed. I can select which OS to boot into using grub. I'd like to ...
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2answers
648 views

How I can enable Linux full tickless mode using CONFIG_NO_HZ_FULL?

Where do I enable the CONFIG_NO_HZ_FULL kernel configuration? Is it something I can set in conf files or is it something that has to be enabled when I build the kernel? I am using CentOS with an ...
0
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1answer
379 views

How can I boot with a compressed rootfs?

My problem is: I cannot use compressed rootfs (the kernel crashes during boot) but uncompressed ones work fine. What I did: I'm using Buildroot 2013.11 to generate Images for my embedded Linux ...
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2answers
185 views

Possible to see dead proccesses?

In man ps, it clearly states the different states a process can have on Linux. D Uninterruptible sleep (usually IO) R Running or runnable (on run queue) S Interruptible sleep (waiting for an ...
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4answers
13k views

How to update CentOS 6.5 to kernel 2.6.32-431?

I need to update my CentOS 6.5 kernel to 2.6.32-431. Running yum clean all && yum update doesn't do it for me. How do I update? And what could be the issue? [root@centos64 ~]# uname -r ...
5
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1answer
134 views

What does “make install” do in the Makefile that comes with the kernel?

I'm trying to identify what does make install do with the kernel and what does the actual "install" of the kernel once it's been compiled means. The problem is I can't really identify the target ...
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1answer
227 views

API for IPROUTE2 in any programming language

Is there any API that can be used to manipulate Linux routing table? I want to write a program that listens to sockets and then modifies routing table accordingly, just a simple code, but need an API. ...
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343 views

CDC ACM doesn't working in a custom linux kernel

I've a cubieboard2 running arch linux with a custom linux kernel. In the cubieboard2 I plugged in my usb-serial device (like an arduino), the device is recognized as CDC ACM. My linux kernel has the ...
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1answer
114 views

leds-pwm driver in linux 3.8

I am using custom board based on beaglebone black. I am trying to enable leds-pwm driver in Linux 3.8 version. But Kconfig says the driver depends on HAVE_PWM config, I am not able to see that ...
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2answers
134 views

GPIO User Space App

GPIO User Space App describes user space application to test the GPIO. Another related link is Linux GPIO Driver. This would be running on a xilinx zynq board having an ARM Cortex A 9 processor. I ...
6
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1answer
229 views

show parameters of running kernel

I would like to see with what parameters the running kernel has been started. i.e., I mean those parameters that are specified with the append option, such as ipv6.disable=1 or rootfstype=ext2 Is ...
3
votes
3answers
3k views

Ping IP works, nslookup fails. New Kernel

I am compiling my own 3.14 kernel. I fear I may have left out some important networking feature to get DNS working. I can't resolve domain names. I can ping my DNS server. I can resolve using that ...
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3answers
321 views

Enabling IP forwarding at kernel compile time

I am compiling a kernel for a router. I know a way to enable IP forwarding in an existing Linux system. At compile time, CONFIG_IP_FORWARD is said to do the same task. I am configuring version ...
0
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1answer
84 views

How to use a built in driver in the kernel?

I am building the 3.14 kernel for a board that requires the intel e1000e driver. I would like this kernel to have the driver built in so that I can remove loadable module support. I have chosen the ...
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1answer
71 views

Can a real-time process exist in the 'expired' queue of linux kernel?

In the Linux kernel 2.4: Real-time processes are given a priority of 0-99 and they co-exist in the ready queue along with the nice processes (who's priority goes between 100 and 139). But real-time ...
2
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1answer
135 views

Kernel Panic on 3.14.0-gentoo on an IBM 9228LGA / SMP Stack Trace

So I've spent the past weekend trying to get this IBM Xeon server up and running. I also took this opportunity to try and get a bootable GPT/Grub2/BIOS setup going. I am able to get the kernel ...
3
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2answers
3k views

Where kernel configuration file is stored?

I currently run Angstrom Linux 2.6.32. I intend to upgrade linux kernel from 2.6.32 to 3.0.7. For this reason, I had to configure kernel 3.0.7 running make menuconfig. Now, I want to compare the new ...
4
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0answers
307 views

EDID Invalid on USB DisplayLink Device

I have a Sabrent USB to HDMI adapter which is a DisplayLink device. It's recognized by udl as being a DisplayLink device, yet seems to be rejected/disabled due to having an invalid EDID: ...
4
votes
1answer
230 views

IPsec doesn't read configuration when the tunnel is deleted

I've created a tunnel between two sites using IPsec. I've made an error in the configuration, the address of the destination was false, so I deleted this tunnel. But after deleting, ipsec tries to ...
4
votes
2answers
2k views

Change kernel parameters at runtime

While trying to fix an obscure hardware bug, it was suggested that adding a couple of parameters to the kernel might resolve the issue. I can of course do that, but I was wondering whether I can make ...
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1answer
2k views

How to apply a patch correctly?

I am trying to patch a linux 3.13.7 source tree to 3.13.8 using the patch-3.13.8.xz file. Since the patch file is in xz format, I used the following command to apply it while in the source tree: unxz ...
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2answers
4k views

How does the system shutdown of a linux kernel work internally?

I have somehow an rough idea of how the userspace and init-system (be it classic init sysV /upstart/ systemd) work at system shutdown. (Essentially there is an order succession of "Stop!", "Please ...
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2answers
216 views

Monitor when read/write on metadata or mmaped files hit the disk

On a server hosting a wide range of websites, I often see IO becoming a bottleneck without being able to identify the processes responsible of IO operations with tools such as iotop, iostat or sar. I ...
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2answers
429 views

System too slow [closed]

My linux system is responding very slowly.I should wait to get the result of my command. How can i investigate to know the problem of his behavior?
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1answer
256 views

How to automate configuration of the Linux kernel build

I'm compiling a flavor of the Linux kernel based on the default configuration (for an ODROID system), with some additional features enabled. I want to automate this process so that I don't have to ...
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1answer
433 views

How to configure bootloader to boot the new kernel?

I succesfully upgraded linux kernel from 2.6.32.61 to 3.0.7 on BeableBoard-xM, following the steps below: download and untar kernel sources 3.0.7 from kernel.org copy kernel sources on /usr/src ...
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385 views

death_handler: Fatal signal 15 received

I have problem with my Linux when I try to shut it down. init 0 I get the following error: death_handler: Fatal signal 15 received setsockopt recvref[30]: Protocol not available The sytem will ...
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0answers
131 views

Interfacing ds1337 RTC on LPC17xx

I am a newbie and I am trying to understand how to interface DS1337(RTC) on LPC17xx Board. This board uses uclinux 2.6.33. .CONFIG: CONFIG_RTC_LIB=y CONFIG_RTC_CLASS=y CONFIG_RTC_HCTOSYS=y ...
0
votes
1answer
56 views

Linux Kernel Compile-time options for Seagate IDE drive

I am configuring linux kernel 3.12.14 obtained from linux.org for compiling using 'make gconfig'. My question is what options exactly I need to enable to make it work for my Seagate IDE HDD? I am ...
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1answer
431 views

Can I upgrade my Linux kernel from 2.6.32 to 3.0.7?

I currently run Angstrom Linux 2.6.32 on BeagleBoard-xM (ARM architecture). Can I upgrade my Linux kernel from 2.6.32 to 3.0.7 and what is the difficulty level in case upgrade is possible? EDIT#1: ...
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0answers
149 views

Is my understanding of kernels correct? [closed]

System: Application OS: Scheduler, VMM, IPC, FS Drivers, dispatchers, VFS The above would be a monolithic kernel. In a monolithic kernel all core OS functions are separate from user space. Functions ...
4
votes
1answer
241 views

Linux and x32-ABI - How to use?

Intro I just moved to a 64bit installation and I'm experiencing big difference in memory usage ( especially for app like chrome, firefox, mysql and java apps ): While before 4gb were enough now ...
13
votes
1answer
11k views

Setting CPU governor to on demand or conservative

I'm struggling with cpupower on ArchLinux. I want to set governor to ondemand or even to conservative. First if I do $ sudo cpupower frequency-info --governors, I only get performance powersave. So ...
4
votes
1answer
857 views

What is the “kernel build”, and where do I get it?

I am trying to compile OpenOnload from Solarflare for my nic on a server that I'm building. It is saying something about not having a kernel build. root@server:/usr/src/openonload-201310-u2# ...
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1answer
716 views

Trouble using `make gconfig` in ubuntu linux

I am trying to compile vanilla Linux kernel 3.12.14 downloaded from kernel.org. When I try make gconfig, it says: * Unable to find the GTK+ installation. Please make sure that * the GTK+ 2.0 ...
5
votes
1answer
3k views

How to build a custom kernel with localmodconfig that support hardware of multiple machines?

When configuring a server to run a single task, like an appliance, there might rise the need to build a custom kernel. For example to save disk space. Ubuntu Core 13.10 amd64 root filesystem is a ...
6
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1answer
370 views

How to strip unused architectures, drivers, etc from headers when building a custom linux kernel?

I am building custom linux kernel packages in a Ubuntu 13.10 amd64 environment usingapt-get source linux-image-$(uname -r)the debian way make-kpkg clean;fakeroot make-kpkg --initrd ...
6
votes
2answers
12k views

Why does Linux have poor battery life by default compared to Windows?

Is there something inherent to Linux operating systems that makes them poor managers of battery power by default? I would have thought a light distro like Lubuntu would have a clear battery life ...
3
votes
1answer
610 views

Kernel /proc ipv6 settings precedence

I'm about to connect our network to the IPv6 Internet and need to control the kernel ipv6 settings found under /proc. I know there are configurations for each interface, for all interfaces, and the ...
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2answers
1k views

How exactly does printk work internally?

I know printf needs help from the OS to do its job. I also know printf does not work in the Linux source code as there is no library. And so we have printk for debugging. How does printk work ...
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1answer
175 views

What is CONFIG_BASE_SMALL=0

Looking at the config file of Linux (that is generated prior to build) I found the following line: CONFIG_BASE_SMALL=0 What does it mean? If I want my linux kernel to be as small as possible shall ...
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0answers
161 views

Looking for a list of modules that are used during boot sequence

I'd like to use deferred init calls. This function allows to load modules in userland, that should actually be loaded during the boot sequence. Just for testing I'd like to modularize as many entries ...
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0answers
256 views

How to cause memory fragmentation on a Linux based embedded device?

Hardware ARM What am I trying to do: Answer: I am trying to create memory fragmentation on a Linux 2.6.31 based swapless embedded device. Why: Answer:I am trying to port some patches to Linux ...
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2answers
5k views

BSD Kernel Vs. Linux kernel? [closed]

I wanted to know in technical terms; what is the difference between BSD Kernel and Linux Kernel. In Linux, we can download the source kernel then patch it and make and make modules it. Even we have ...
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1answer
8k views

Linux: What is a tainted kernel?

Under certain conditions, the Linux kernel may become tainted. For example, loading a proprietary video driver into the kernel taints the kernel. This condition may be visible in system logs, kernel ...
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3answers
2k views

Why there are many BSD systems but only one Linux kernel?

Why there are many BSD systems but only one Linux kernel? I wonder why BSD was forked many times, but no such thing with Linux.
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3answers
4k views

Try to disable console output, console=null doesn't work

as mentioned above, I want to to completely turn off the console output, but putting console= or console=null in the kernel command line doesn't change a thing. When I enque quiet to the kernel ...
4
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1answer
103 views

How to relate a kernel config setting to the source files?

Here is an example that will explain better: I have a selected the audio driver from the picture and i would like to browse through its source. How do i get to the path of the source files from ...