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

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What are the programs/commands which the magic SysRq key invoke?

From Magic SysRq key The magic SysRq key is a key combination understood by the Linux kernel, which allows the user to perform various low level commands regardless of the system's state. It ...
0
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1answer
16 views

How do you install the FreeBSD10 kernel sources?

I am trying to run an update of freebsd10 and I am being asked for the kernel sources ===>>> Launching child to update lsof-4.89.b,8 to lsof-4.89.d,8 ===>>> All >> ...
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1answer
31 views

Where is routing table stored internally in the Linux kernel?

When I execute route -n, from where exactly (from which structs) is the information displayed retrieved? I tried executing strace route -n but I didn't help me finding the right place it's stored.
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0answers
10 views

Why there is PPPd instead of all PPP software in kernel?

Are there any reasons why the need of PPP software separation from kernel and process (PPPd)?
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0answers
23 views

How to install grsecurity [closed]

So I verified the grsecurity and kernel I did the first part from this http://en.wikibooks.org/wiki/Grsecurity/Configuring_and_Installing_grsecurity But now i have a folder linux-3.14.42 and i dont ...
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0answers
17 views

Can anyone tell me how to compile custom linux kernel? [duplicate]

I want to know the complete method of compiling of a linux custom kernel.
0
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2answers
47 views

how to untar file in linux red hat?

I am compiling linux red hat stable kernel on red hat linux and the error which I am facing is as below
2
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1answer
74 views

Kernel Backport for Debian Jessie?

I installed the 32 bit version of Debian Jessie (8.0) on an Asus X205TA. The Asus X205TA laptop is quirky like a lot of Intel Baytrail Atom laptops/tablets in that it has 32 bit EFI but a 64 bit ...
2
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0answers
14 views

Using dkms to patch kernel

I need to apply a kernel patch(https://lkml.org/lkml/2015/3/31/929) to get my touch-pad working properly. I am thinking that I should be using dkms, to do this. Most of the stuff I am reading is about ...
2
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1answer
15 views

bdl_pos_adj: set IRQ timing workaround for hda-intel

I get following errors in my logs: kernel: snd_hda_intel 0000:00:1b.0: IRQ timing workaround is activated for card #0. Suggest a bigger bdl_pos_adj Google found some old posts here and ...
0
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1answer
21 views

Kernel modules for compiled kernel

I cannot find kernel-headers. For the first time I compiled and installed the latest kernel (4.0.3) on my Debian Wheezy, and now I am trying to install ndiswrapper using module assistant. For that, ...
0
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1answer
15 views

Why does user mode linux spawn 4 processes?

If I start User Mode Linux with this command: ./kernel32-3.19.8 ubda=./Debian-Wheezy-x86-root_fs mem=128m On Debian GNU/Linux 8 (jessie) with one CPU core, why do I see 4 processes in top: 1608 ...
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26 views

Linux Driver for USB “reverse” mass storage device

I'm developing a USB device that I want to read and write in virtual filesystems that are in my computer. Basically the device needs to be able to read, write and get the virtual filesystem size. Some ...
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0answers
42 views

make: ***No rule to make target 'xconfig'. Stop. how to remove this error? [closed]

actually I am compiling my kernel and make command is not working completely so what should I do to make config file of newly kernel? this is happening
0
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1answer
28 views

Not able to reinstall the kernel or to use the latest version

On a ubuntu server, I try to di "sudo modprob" and I have this error : $ sudo depmod [sudo] password for deployer: depmod: ERROR: could not open directory /lib/modules/3.8.0-38-generic: No such file ...
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2answers
39 views

how to check a kernel version which was used when building package

I use apt when downloading packages from Ubuntu repositories. How can I check which kernel version was used when building package? When it is important (kernel version of the build server vs. kernel ...
0
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1answer
26 views

Downgrade Debian kernel

I have a requirement to install Debian kernel 3.2.65-1+deb7u2. I cannot seem to find the kernel. I have taken the following steps: Installed kernel 3.2.68-1+deb7u1. Downgraded the kernel to ...
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0answers
22 views

READ DMA Error after Installing CentOS 7

I have been trying to install CentOS7. After I installed it, I see the following message sporadically. ata2.00: exception Emask 0x10 SAct 0x0 SErr 0x4050000 action 0xe frozen ata2.00: irq_stat ...
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2answers
32 views

why do some network cards need to load external firmware?

I have read this question/answer, but I still do not understand why some network cards work perfectly well without any additional firmware, whereas others need to load firmware to work. As a specific ...
0
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1answer
22 views

GNU\Linux clustreing , Which level? Which application? [closed]

I need to start GNU* clustering, But I have problem, Which level: DB level? (replication) file system? (distributed) process level ? (such as intel fortran for civilization softwares) new process ? ...
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0answers
30 views

Limit system processes using cgroups

My server runs several dozens of processes that are not in my control (mostly monitoring software). According to my application logs, sometimes some of the third party processes try to allocate too ...
0
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1answer
12 views

Uprobes Status on the present linux kernel

I know uprobes was introduced on kernel 3.5 has it survived or is it dropped, is it still available on kernel 4.x
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0answers
17 views

RHEL6 Idle Thread Behavior

I am doing some cpu performance profiling with the perf tool on a RHEL6 box running weblogic12g. It looks like the idle threads are presented as native_safe_halt in the stack profile but ...
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0answers
15 views

Filesytem errors during boot

I am using OMAPL138 and kernel version 2.6.37 and I would like to improve the boot time of my system. I made some progress on this, but I still have some errors which may be causing delay in the boot ...
5
votes
1answer
36 views

What extras do I need to maximise battery life on a laptop? (And how to stay current)

Now, I know that this question has probably been asked 1000 times - but as far as I can tell, the answer seems to change a lot over time. While researching, I came across powertop, pm-utils, tlp, ...
0
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1answer
79 views

Centos 7.1 still using outdate kernel 3.10 how to upgrade to kernel 4.0

I'd like to upgrade my Centos 7.1 kernel from 3.10 to 4.0 i did successfully in Ubuntu 15.04 using Linux 4.0.1-040001-generic even though i updated it manually it's works fine so please could ...
0
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1answer
36 views

crypto kernel module not available on Raspberry pi 2 (linux 3.18.11)

I'm trying to use dm-crypt on my Raspberry Pi 2 with Raspbian (debian) to open a trueCrypt volume, but i get Required kernel crypto interface not available. Ensure you have algif_skcipher kernel ...
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0answers
5 views

Having problems with negative monitor channel, intimidated!

When I try this command: aireplay-ng -1 0 mon0 -a xx:xx:xx:xx:xx:xx I get this output: No source MAC (-h) specified. Using the device MAC (xx:xx:xx:xx:xx:xx) 17:51:23 Waiting for beacon frame ...
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0answers
10 views

How is a process state updated to blocked state (TASK_INTERRUPTABLE)? [migrated]

When a process is waiting for IO, how is the task state updated to TASK_INTERRUPTABLE (that is, blocked)? Imagine this case, a process issues an IO request to a block device. According to my ...
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0answers
29 views

Kernel problem after editing filesystem.squashfs

I use Kali Live linux (which is based on Debian), today I tried to edit filesystem.squashfs file which is located at /live/filesystem.squashfs using squashfs-tools. First I extracted this file using ...
2
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1answer
39 views

Relationship between IO scheduler and cpu/process scheduler?

The concepts of IO scheduler and CPU scheduler confuse me. Below are my understanding: Linux uses CFS scheduler + nice values by default to schedule processes. Each process has an IO queue. There ...
3
votes
1answer
142 views

Which file in /proc gets read by the kernel during the boot up process?

Which file in /proc gets read by the kernel during the boot up process? This was a question on my LPIC 101 test that I think I might have answered wrong. I searched on google and some other places but ...
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0answers
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shm.h header file not found in Linux 3.13.3 [migrated]

I am new to for Linux. I have downloaded Linux 3.13.3 and I am trying to make a system call for shared memory. I have created a "hello world" system call and it runs perfectly. When I compile my ...
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1answer
57 views

virtualbox can not create new virtual machine

I'm try to make a new virtual machine but virtualbox have this error in end step : Failed to create a new session. Callee RC: NS_ERROR_FACTORY_NOT_REGISTERED (0x80040154) and in terminal this shwn ...
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0answers
19 views

Continuety of driver support in linux kernel

I am an embedded GNU/Linux learner. I understand with the new Kernel, driver support for most added hardware is coming through Device Tree Structure (DTS). But I have found out that there are still ...
3
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2answers
350 views

What are the concepts of “kernel ring buffer”, “user level”, “log level”?

I often saw the words "kernel ring buffer", "user level", "log level" and some other words appear together. e.g. /var/log/dmesg Contains kernel ring buffer information. /var/log/kern.log ...
3
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2answers
65 views

Set default kernel in GRUB

How can I pick which kernel GRUB2 should load by default? I recently installed a the linux realtime kernel and now it loads by default. I'd like to load the regular one by default. So far I only ...
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2answers
70 views

Are “kernel mode” and “user mode” hardware features or software features?

I read that there are two modes called “kernel mode” and “user mode” to handle execution of processes. (Understanding the Linux Kernel, 3rd Edition.) Is that a hardware switch (kernel/user) that is ...
0
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1answer
94 views

VMware and kernel 4.0

I'm trying to install VMware in Elementary OS freya updated with kernel 4.0 but it doesn't start. The error suggests incompatibility with kernel 4.0. How can I solve this?
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1answer
47 views

What are the deb files for installing a kernel for?

When installing a kernel in Ubuntu(e.g. http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.0-vivid/), what are the files for respectively: linux-headers-4.0.0-xxx_all.deb ...
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vote
2answers
71 views

How to test modified FreeBSD source code?

I am trying to modify the default congestion control algorithm in FreeBSD (NewReno) by creating a copy of the source file (cc_newreno.c, located in /usr/src/sys/netinet/cc) called cc_newreno_mod.c and ...
0
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2answers
53 views

why can't we install application compiled for Ubuntu, on Linux mint, or some other distros with same kernel?

When i try to download some applications like VLC, it shows in download options, various Operating systems which includes Linux mint, Ubuntu etc. Though Linux mint's kernel is from Ubuntu, still they ...
21
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4answers
769 views

Making Linux read swap back into memory

The Linux kernel swaps out most pages from memory when I run an application that uses most of the 16GB of physical memory. After the application finishes every action (typing commands, switching ...
2
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0answers
36 views

is THP good or bad for MySQL Server?

Linux kernel new feature called Transparent Huge Pages (THP) which is by default enabled on CentOS 6.x and above OS. Is THP good for MySQL DB machine? I am trying following to disabled THP but seems ...
2
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1answer
47 views

How does ath9k introduce itself to mac80211?

My question is about Linux kernel and ath9k wireless driver: How does ath9k announce itself to the mac80211? How come the mac80211 knows how to configure ath9k? Thanks in advance
2
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2answers
37 views

Is there any Syscall table just like Interrupt Table?

Are the system calls like fork(), exit() saved in some kind of function pointer table , just like the Interrupt Descriptor Table ? where does my OS go when I call my fork() or exit() ? I guess this ...
0
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1answer
25 views

Kernel Firmware for Radeon

I'm building LFS. I was trying to enable Ati radeon drivers in the kernel, but it didn't seem to work, so I did a little Googling and found that the there is something called firmware which the kernel ...
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0answers
32 views

No sound with audio jack

I am using a Debian wheezy on Netbook eeepc 1001px After last kernel update When I plug the audio jack, I can here the electric charge but no sound when I remove it the internal speaker works ...
3
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0answers
53 views

Problems with file system

I created a partition with EXT4 file system and when I'm writing in this partition frequently the Kernel return the following error: Jan 01 01:17:54 infobuffer360 kernel: r7:c0561280 Jan 01 01:17:54 ...
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3answers
1k views

Is USB-to-USB data transfer between two Linux OSes possible?

I want to create a USB-to-USB data transfer system in Linux (preferably Ubuntu). For this I want to use no external hardware or switch (except this cable). It's going to be like mounting a USB drive ...