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

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2
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1answer
53 views

Embedded board - Install debian

I'm new in embedded world and I'm quite confuse. I have a Freescale board which contains an ARM926 32 Bits and mounts Linux 2.6.35. First question: this is the kernel, right? Second question: I ...
0
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0answers
43 views

Find system idle time using any system call in microseconds

For the perf analysis and to make decision based on system and app performance I need to find the idle time of system. I want the precise value in microseconds. I know that I can get the value in ...
8
votes
1answer
997 views

Increase FIFO size limit

Thanks to the answers to my other question, I now understand that FIFO on Linux, i.e. /dev/xconsole has a buffer limit of 64 KB. How can I increase this limit to 128 KB? Apparently, I will need to ...
1
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0answers
126 views

weak-modules from module-init tools directory

I see in module-init directory, files named as weak-modules*. bash # ls /usr/lib/module-init-tools/weak-modules* /usr/lib/module-init-tools/weak-modules /usr/lib/module-init-tools/weak-modules2 ...
0
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1answer
102 views

Root file system vs partition's file system

Based on the first paragraph from linfo as quoted below, one can conclude that root file system is actually the partition's file system where Linux is installed. The root filesystem is the ...
1
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0answers
85 views

Linux shared mount point inconsistent between child and parent processes

Let me try to explain the background: In main bash: We use mount --bind /tmp/source /tmp/target mount --make-shared /tmp/target to create this shared mount point target And then we use unshare ...
1
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2answers
112 views

Do i need to recompile the whole linux kernel

If I change some part or some subsystem of Linux kernel, do I have to recompile the whole kernel? Is there any way to recompile only that particular subsystem?
0
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0answers
79 views

How udev works when we connect USB device

Whenever, I am connecting USB device like Pen drive, Bar-code scanner, mouse etc. udev creates dynamic files in /sys/bus/usb/devices/. like 1-1, 2-1. inside these files I am getting all information ...
0
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0answers
16 views

How to create Cent OS 6.5 DVD with the 3.10 or 4.0.1 Kernel?

The Cent OS 6.5 comes with a old 2.x kernel. I would like to build new kernel for it(3.10 or 4.0.1) and re-package it with the Cent OS 6.5 OS DVD. How can I do this?
0
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0answers
31 views

RHEL7 : Freeing memory allocated for Block IO i.e. bio -> bio_destructor

I want to know HOW memory allocated for BIO gets free specific to RHEL 7. I think, in RHEL 7 , bio->destructor field is removed from the bio structure. So, how exactly the memory will be freed? ...
1
vote
0answers
84 views

Change device framebuffer to use overlay layer

I'm using atmel-hlcdc driver to control a LCD panel and an application uses the /dev/fb0 framebuffer created by the driver. The display works fine except that the panel's standard orientation is ...
5
votes
0answers
116 views

Where in GRUB2 source code is the handover/jump to kernel code?

I'm looking for the line of code where GRUB2 finally jumps to kernel code and thus hands over execution on x86 systems? I guess it's in an assembler file since this is very low architecture stuff. I ...
2
votes
1answer
57 views

How to reduce bootup time of linux? [closed]

First of all, I appreciate for taking times. I have a PC with the following configuration: 1- CPU: Cor2Duo 2- Ram: 2 GB 3- 40 GB HDD I just need serial and network. I don't need Xwindow. I just ...
0
votes
1answer
342 views

Kernel panic – not syncing: Fatal machine check on current CPU

In the latest few weeks, my machine rebooted a few times with this kernel panic error. It's a fedora 21, Linux 4 machine on an AMD E-350 APU. I didn't observe any pattern. When I reboot, the BIOS ...
1
vote
0answers
43 views

Detecting Hardware of the Dyconn Dubbler Dock

I purchase USB3 dual-hard-drive docking station from Fry Electronics called the Dyconn Dubbler Dock. When I plug this device into an Ubuntu Linux 15.04 laptop (kernel: 3.19.0-26-generic), I see no ...
1
vote
0answers
50 views

What does raw_spinlock mean? [closed]

I was studying struct raw_spinlock which is in the /usr/src/linux/include/linux/spinlock_types.h was like this: typedef struct raw_spinlock { arch_spinlock_t raw_lock; #ifdef ...
2
votes
1answer
194 views

How to make SysRq working on laptop?

My /proc/sys/kernel/sysrq contains the number 502, but Alt+SysRq+... seems not to work on my HP Pavilion laptop. How can I fix that? Update 1: By the way: neither my print-screen-key nor any other ...
1
vote
2answers
49 views

compling kernels for armhf

I am trying to compile my own kernel but I am having some issues with understanding. I am using the latest kernel available from kernel.org. My issue is at current: I have zero clue on what options ...
0
votes
1answer
1k views

Downgrade Kali Linux

I have upgraded my system to KALI Sana 2.0 and kernel 4.0.0-Kali1-amd64. Previously I had the version kali-linux 1.1.0 and kernel 3.18-Kali1-amd64. The reason I want to downgrade is that Kali Sana ...
0
votes
0answers
100 views

Registering virtual SPI master device

I need to create a virtual SPI master device. Having a proprietary solution that communicates directly with a sensor using SPI I want to move the sensor away. To do so I want to create a kernel ...
1
vote
3answers
392 views

Everything is a file?

In Linux, every single entity is considered as FILE. If I do vim <cd-Name> then, vim will open the directory content into it's editor, because, it do not differentiate between file and ...
0
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0answers
33 views

How to use RTNETLINK in kernel module/kernel space to extract routing table?

I want to extract routing table information in kernel module using Netlink sockets? Is it possible? I know that in user space we can do that. Regards
2
votes
0answers
45 views

What does Linux wait for when switches from Xorg to text console?

Sometimes my Xorg hangs and locks the console dead, with a “stale frame” of GUI on the monitor. Hardware and driver-related problems are likely (see here for description of particular configuration), ...
1
vote
1answer
145 views

How download complete patch series from patchwork?

I want to download the patch series RFC PATCH 00/26 i.MX5/6 IPUv3 CSI/IC In patchwork I can get access to individual patches https://patchwork.linuxtv.org/patch/24331/. But downloading 26 patches and ...
1
vote
1answer
32 views

Why is debug_putstr() not being printed during boot?

I'm asking myself why debug_putstr() in arch/x86/boot/compressed/misc.c is not being printed during x86 boot phase, though it is configured to do so with GRUB_CMDLINE_LINUX_DEFAULT="". On other ...
2
votes
1answer
221 views

check-config errors on Linux 3.19.0 kernel, configured under Ubuntu 15.04 x86-64

I'm new to configuring Linux kernels, and am receiving the following errors when running config-check: check-config: /tmp/tmp.tnqExc0fHn/CONFIGS/amd64-config.flavour.generic: loading config ...
1
vote
0answers
68 views

Best way to approach HID_MAX_USAGES kernel errors?

This is an issue I have for the second time now: basically, an USB based device reports some wrong numbers for "HID_MAX_USAGES", resulting in the kernel giving an error message and the device not ...
0
votes
2answers
99 views

Compiling Kernel : Unable to locate ncurses

I am trying to compile the kernel. I downloaded the source . When I tried 'make menucionfig'. I got following result : * Unable to find the ncurses libraries or the * required header files. * 'make ...
4
votes
5answers
333 views

Is there a plain GNU/Linux OS?

I'm currently looking at all the different Linux distros and can't seem to find the original GNU/Linux OS. Apparently there is a GNU System which combined the GNU project with the Linux kernel. How do ...
4
votes
0answers
296 views

Kernel - Measuring the rate of timer interrupts

I am working on optimizing kernels of my boxes for telephony, which involves (among other things) adjusting the HZ rate and the preemption model. Initially the kernel was compiled with the default ...
0
votes
0answers
7 views

.config not getting updated after modification to tegra3_android_defconfig

.config not getting updated after modification to tegra3_android_defconfig After adding a module(MODULE_XX_CONFIG=y) inside tegra3_android_defconfig, I did "make tegra3_android_defconfig" though the ...
1
vote
0answers
46 views

Using two memory controllers with SPARSE_MEM on AT91SAM9G45

There are lot posts on this problem in google, but I have tried all the solutions but they are not working for me, so I'm posting here… I am working with AT91BootStarp 3.5.9 with linux kernel 3.6.9. ...
1
vote
2answers
261 views

What files does the Linux kernel access?

/init during early userspace, /sbin/init, and /sbin/request-key are three files that the Linux kernel accesses (and they are all executables). Are there any other files, possibly non-executable ones, ...
70
votes
6answers
13k views

Why is the Linux kernel 15+ million lines of code? [closed]

What are the contents of this monolithic code base? I understand processor architecture support, security, and virtualization, but I can't imagine that being more than 600,000 lines or so. What are ...
2
votes
0answers
41 views

Replacement for cap-bound

We have an old Linux from scratch kernel used in one of our systems, that uses the old cap-bound mechanism (modifying /proc/sys/kernel/cap-bound) to restrict the capabilities of the system. This was ...
0
votes
0answers
152 views

Wifi driver on Kernel 4.x

I've upgrade my kernel from 3.19 to 4.1.5 but the Wifi driver don't work. Does anyone know how I can make it work? I've tried a few methods but it doesn't work. First method I've tried was to try ...
5
votes
3answers
203 views

How can I verify `nice` is working?

Looking at different jobs running on a system with shared resources, it seems the nice values are being ignored. Many jobs with nice set at 19 are running at 100% cpu load while other many other jobs ...
2
votes
1answer
2k views

CPU warning - abrt-watch-log

I am running a Red Hat Enterprise Linux Server release 7.1 (Maipo) on Intel(R) Xeon(R) CPU X5690 @ 3.47GHz I keep getting this error in abrt-watch-log. root 888 1 0 Aug03 ? ...
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0answers
45 views

Print kernel memory layout

Userland memory layout can be inspected by looking into /proc/self/maps. I am wondering if there is a similar facility allowing to inspect runtime kernel memory layout?
0
votes
1answer
19 views

Do less severe log level INCLUDE more severe log levels?

Will loglevel=7 include the logs, for example, that would be produced by loglevel=0? http://www.makelinux.net/ldd3/chp-4-sect-2
1
vote
0answers
34 views

Unattended build of linux kernel

Goal: I am trying to automate the 4.0.4 kernel build to provision it to multiple machines. Since AUFS no longer ships in "extras" package, I am compiling it as well, and then adding via make ...
1
vote
0answers
164 views

Where do these boot log entries come from and who creates them?

I'm wondering what kind of code writes these first two lines into /var/log/syslog while booting my machine: Aug 4 10:13:48 HOSTNAME kernel: imklog 5.8.11, log source = /proc/kmsg started. Aug 4 ...
17
votes
1answer
342 views

Process which locks up, ignores SIGKILL, is runnable (not a zombie or in uninterruptable sleep). What state is it in?

I have a process which several times now has stopped responding and appears to be completely locking up. It doesn't respond to any attempt at strace or peeking with gdb (gdb just hangs on a wait4() ...
0
votes
1answer
66 views

Increasing Kernel Mode Setting (KMS) scrollback buffer size

I'm using Kernel Mode Setting to set my server's tty resolution. I added GRUB_GFXMODE=1280x1024x24,auto to /etc/default/grub, and GRUB_GFXPAYLOAD_LINUX=keep was already there. There's no vga= or ...
1
vote
1answer
458 views

Unable to install new kernel in ubuntu server. “gzip: stdout: No space left on device” error even though abundant disk space

I am trying to install a new kernel on Ubuntu Server and I am unable to complete it due to a "gzip: stdout: no space left on device" error. The full error was produced after running sudo make ...
-1
votes
1answer
45 views

Is it possible to delay booting the system after the user has pressed the power button? [closed]

I want to delay the time to load the kernel after the user has pressed the power button by 10 seconds. Reasons for this is a machine we have built which requires other components to start sending data ...
0
votes
2answers
1k views

Uboot passes arguments to kernel!

How can uboot pass command line argument to kernel? I did some googling and got to know that it uses the bootargs environment variable. There it was mentioned that setenv bootargs key=value. Since I ...
2
votes
1answer
42 views

Recompile kernel without modules that are not currently in use

Is there a neat way of stripping the Linux kernel to only support the devices that are currently in use. After NVIDIA complaining about GCC version mismatch, I decided to recompile the kernel with the ...
1
vote
0answers
52 views

What is the Linux scsi mid-layer

In the Linux storage stack there are 3 levels: upper, mid and lower. Therefore, I know what it is in that sense. What I'm hoping someone will know is, what files in the Linux source tree actually ...
3
votes
1answer
317 views

Kernel address space layout

Userland address space is well documented, which includes segments like heap, stack, .text, .bss, etc. But there is not enough documentation on kernel address space. Since certain virtual address is ...