The kernel of operating systems popularly known as Linux, or sometimes GNU/Linux.
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1answer
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How to learn kernel programming from the start? [on hold]
I have completed my graduation recently. And I have only basic knowledge in C. But I would like to work on the Linux Kernel, and customize it according to my needs. Not only customize I would also ...
2
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0answers
19 views
how to stop kernel threads preempting real time user space processes?
I created some processes in user space and tried to visualize its working in kernelshark with the trace recorded using trace-cmd. But kernel processes like the ones shown below are preempting my ...
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0answers
37 views
How or where can I download the entire Linux 3.11 kernel?
I want to go through it and make adjustments.
2
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1answer
30 views
CONFIG_RTC_SYSTOHC: how to use the NTP synchronization option in the kernel
I have noticed in kernel 3.10, there is an option CONFIG_RTC_SYSTOHC
Device Drivers -> RTC -> Set the RTC time based on NTP synchronization
The help says:
If you say yes here, the system ...
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2answers
38 views
Which file in kernel specifies fork(), vfork()… to use sys_clone() system call
When ltrace is used for tracing the system calls, I could see that fork() uses sys_clone() rather than sys_fork(). But I couldnt find the linux source where it is defined.
My program is
...
3
votes
1answer
59 views
How can I override the kernel default options for mount?
I'm struggling with a program that creates a file system in a file and mounts it as a loopback device. The purpose of the program is to create a clone of the root file system and it thinks it's being ...
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0answers
23 views
“in vfork() , after calling _exit() the child never comes back to the execution ” is this true? [migrated]
I am working on the unix system calls and process control.
I know that when vfork() is called , the control given to the child process and when child process is done , it calls _exit() , and then the ...
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2answers
40 views
Does a fault in a kernel module necessarily result in a system crash?
Or is it possible to overcome the fault, since the code isn't in the monolithic part of the kernel?
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3answers
1k views
Does the kernel have a main() function? [closed]
I am learning device drivers and Kernel programming. According to Jonathan Corbet's book, there is no main() function in device drivers.
So I two questions:
Why don't we need a main() function in ...
2
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2answers
84 views
Install kernel-devel of specific version in fedora 19
So I have different "installed" kernel versions from the running kernel version, on my fedora 19 machine.
To give a more clear idea, here is my terminal output:
[user@home ~]$ uname -r
...
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2answers
52 views
Can I create a virtual ethernet interface named eth0?
This is a rather odd question, because normally it would not make sense to do that.
I am running Arch based on the Linux 3.10.5-1 kernel. The system uses the new de-facto naming conventions of ...
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0answers
25 views
FREERADIUS shutting down automatically
I've installed freeradius 2.0.5 with ipkg on Linux 2.6.33.2 and it's shutting down automatically after few seconds. Before it's going down radius works fine. I can't find anything in syslogs, I have ...
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95 views
PC sudden shutdown, Sensors show normal temps, Thermal event interrupts shows 1276
I'm experiencing sudden shutdowns on my Linux systems.
Using Ubuntu 12.04, my kernel version is 3.5.0-37-generic #58~precise1-Ubuntu.
Running a Acer M5 581t(G) with 6 gigs ram laptop. I have been ...
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votes
0answers
32 views
segmentation fault caused by [vdso] and [vsyscall]
While running a program it generated a long output with these three lines at the end:
7fff584cb000-7fff584ed000 rw-p 00000000 00:00 0 [stack]
7fff58563000-7fff58565000 r-xp ...
2
votes
1answer
30 views
Generate interrupts for purpose of stress testing
I'm testing the quality of a generated PWM signal on a Raspbery Pi. I would like to test how it behaves if there are lots of interrupts coming.
Is there a way to fake interrupts or force 2000 ...
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0answers
44 views
Beaglebone Black Device Tree for LCD4 cape
The device tree for LCD4 cape is located at /lib/firmware/BB-BONE-LCD4-01-00A1.dts When I looked into it, the declaration of those GPIO buttons confuse me. There are five buttons according to ...
0
votes
1answer
43 views
Building Linux from Scratch stuck, incompatible sed version? [duplicate]
I am trying to build Linux from Scratch per LFS website
While I was able to install all the packages until 6.7.1 without any error, I am stuck at Installation of Linux API headers (This is after I ...
3
votes
2answers
65 views
Strange temporary network outage in Linux [duplicate]
I'm facing a very annoying problem that I noticed a week from now and for which I can't find an answer: my network suddenly stops responding, usually coming back exactly 25 seconds later. I was using ...
0
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0answers
15 views
Accessing .eh_frame data during execution [migrated]
I'm trying to access the contents of .eh_frame section of a running program from within it (specifically, the program is Linux kernel 2.6.34.8). The .eh_frame contains useful data used for exception ...
2
votes
1answer
66 views
Linux (debian/testing) cannot boot after installing kernel 3.9.1
Today I wanted to upgrade the kernel on my debian/testing system from 2.6.32-5-686 to 3.9-1-686-pae. So I installed the image by sudo aptitude install linux-image-3.9.1-686-pae (or something like ...
1
vote
1answer
33 views
What value is stored in linux xtime variable?
Whenever I print the value of /proc/interrupts the value of rtc0 in IRQ8 which is for RTC shows only 1 interrupt on CPU0. I have read that when booting the value of the xtime variable is stored from ...
2
votes
1answer
48 views
Why CONFIG_NO_HZ is not set by default
In the Linux Kernel CONFIG_NO_HZ is not set. But an initial reading suggests that setting that option would be nice from a performance point of view. But reading some posts like this made me think ...
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1answer
48 views
Why can't new versions of kernel solve the backlight problem?
Currently I am using Linux 3.8.0-27-generic kernel on my Samsung laptop. I replaced grub configuration file with the following text to make backlight control work:
GRUB_CMDLINE_LINUX_DEFAULT="quiet ...
2
votes
1answer
64 views
What is meant by interrupt remapping in Linux?
Can anyone explain what the interrupt remapping is?
Would turning this feature off in the Linux kernel cause any problems, or bring any benefits?
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1answer
109 views
Efficiency of Linux Kernel [closed]
In a documentary, Linus Torvalds says that even in the future, if anyone wishes to make a new OS from the scratch, they could use the Kernel which he wrote. It was very inspiring.
Is it true that ...
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2answers
110 views
Can system calls be interrupted?
Please comment on the following sentence:
On the standard Linux kernel without the rt patch, interrupts can't
interrupt ongoing system calls. The reason why our machine doesn't
stop working ...
2
votes
1answer
53 views
Are time interrupts always followed by a scheduler call?
When a timer interrupt occurred the ISR is called to service the interrupt.
Is it okay to assume that every timer interrupt ends with a call to the scheduler on which process should continue running ...
0
votes
1answer
23 views
CentOS - acts abnormal every week and causes my whole setup to be down, how can I rollback / restore back to one week?
I have CentOS and Red hat enterprise Linux running, where I have now working Google Apps Engine and related other Python web applications.
Every week or depending on any Google Apps Engine latest ...
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0answers
25 views
boot updated kernel image on beagleboard
Boot updated kernel image on beagleboard.
I had installed a kernel on Beagle-board to update image of kernel to it. I've used this command:
$ sudo apt-get install linux-image-3.2.0.49-omap
It ...
1
vote
1answer
81 views
What are PCI quirks?
I hear a lot about PCI quirks when reading about the Linux kernel, but no website explains or defines PCI quirks. What are PCI quirks?
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votes
2answers
51 views
How can I know if the current kernel was compiled with a certain option enabled?
Is there a way to know if the kernel was compiled with a certain option activated (i.e. CONFIG_PROC_EVENTS=y) without having to pull out the kernel sources package and looking in the config file?
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31 views
to update kernel on Beagleboard
i had compile a kernel for beagle-board with kernel version 3.6.8.x4 with 12.04.1 LTS but after recompile kernel (3.10.1 stable) in this process i just
copying the uImage into boot of rootfs section ...
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0answers
38 views
Will there be any security problem to permit non-root user set up a loopback devices?
if the user has full access to the image file (iso or disk image), will there be any security problem to permit him set up a loopback device backed by this file ?
% ls -al /dev/loop* ...
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0answers
108 views
Allocated Memory difference in xen guests after using Linux 3+ kernel [closed]
Can someone explain to me why there is a memory difference in Guests with the same configuration?
Hypervisor: xen 4.2 64 bit
VM1: Centos 5.7 with 2.6.18-274.el5xen
Assigned memory from xen is ...
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1answer
42 views
Significance of certain folders in linux kernel tree
While going through Linux Kernel Source tree, found certain folders, explanation of which was not seen in the popular sites. Could someone tell why these folders are there like:
block - This is not ...
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0answers
29 views
configure allowed_tcp_congestion_control via config files in linux kernel
I am trying to come up with a custom set of TCP congestion control variants as part of the tcp_allowed_congestion_control. I do have multiple variants on my tcp_available_congestion_control list but ...
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1answer
47 views
“sync” before drop_caches,is it necessary?
I have read a lot of docs saying, it is good idea to do a sync before doing echo [1,2,3] > /proc/sys/vm/drop_caches.
I am not able to understand why it is needed, drop_cache is a non-destructive ...
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0answers
58 views
what is the linux boot param “memmap” equivalent in freebsd
In linux kernel, there is an option to reserve a portion of system ram i.e
memmap=512M$2G (boot param) Here 512M starting from 2G would be reserved and not available to OS
What is the equivalent in ...
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votes
2answers
33 views
Resuming the Linux Kernel Configuration
I am configuring a Linux kernel before I compile the code. However, after I was thirty minutes into answering the many questions concerning various kernel settings, I accidentally pressed Ctrl+C. I do ...
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0answers
36 views
Dom0 Xen kernel doesn't work with isolinux bootloader
I build my Dom0 kernel for Xen, but during boot, returns me the error:
elf_xen_note_check: ERROR: Will only load images built
for generic loader or Linux images
I'm using isolinux because I need ...
1
vote
1answer
80 views
How to log iptables as of kernel 3.9.0?
What is the right way to log iptables as of kernel 3.9.0?
I can no longer append a logging rule such as:
# iptables --new-chain droplog
# iptables --append droplog --jump LOG --log-level info
...
0
votes
0answers
35 views
Wireless not detected in Linux Mint
I have updated my Linux Mint kernel from 3.2.0-23-generic to 3.8.0-23-generic, because the old kernel version freezes quite often.
Now, I have a problem that my wireless network is not detected.
...
0
votes
1answer
87 views
After upgrading to linux kernel 3.9, kde does not start correctly
I recently upgrade my debian from kernel 3.2 to 3.9. This leads to a strange problem. After booting to kernel 3.9, it directly goes to tty7 instead of kde login. I can identify that kdm is up and ...
2
votes
0answers
90 views
What changed between kernels 3.7 and 3.9 that affects LVM/RAID root file systems?
I'm trying to fix a (very messy) system that the user hosed by running a kernel upgrade from 3.7.10 to 3.9.6. the root file system is on an LVM volume on top of a software RAID array. The boot manager ...
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0answers
50 views
Understanding the Buddy Allocator [closed]
I have a conceptual doubt in understanding the way Linux Kernel manages Free blocks. Here is what I interpreted through reading so far.
The Buddy Allocator implementation is allocation scheme that ...
2
votes
1answer
36 views
How can I find the Secure Attention Key (SAK) on my system and can I disable it?
In answer to My process was killed but I cannot understand the kernel notice, I was pointed to some documentation on the Secure Attention Key (SAK) on Linux. I have a embedded system generated using ...
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votes
1answer
32 views
get Various types of address used [closed]
How to get various address ranges of a running machine or a crash dump?
User virtual address
Physical address
Bus address
Kernel logical address
Kernel virtual address
I don't need the bus ...
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vote
2answers
65 views
Download the Complete Linux Kernel Collection
I am wanting to download EVERY version of the Linux kernel as source code, Debian files, and RPM files. Where can I find a single site where I can download them all at once? If that is not possible, I ...
2
votes
2answers
119 views
How do I get a linux kernel patch set from the mailing list?
I don't subscribe to the linux-kernel mailing list, but I want to get a set of patches that were posted a few weeks ago and apply them to my kernel for testing. I'm very familiar with patching, ...
2
votes
1answer
43 views
What do the fields in the libata device probe line in dmesg mean?
When the kernel boots, it prints out lines like this for each SATA device:
[ 0.919450] ata2.00: ATA-8: ST2000DM001-1CH164, CC24, max UDMA/133
[ 0.919487] ata2.00: 3907029168 sectors, multi 16: ...
