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

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788 views

Why isn't “REISUB” working on Debian?

I'm using Debian 'Jessie'. Sometimes my computer freezes, and then I can't use Ctrl+Alt+Del to reboot, Ctrl+Alt+Backspace to kill the X Window System nor Ctrl+Alt+F1 to open a new shell. I've read in ...
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1answer
40 views

linux + grub.conf not exist

I just need to check some redhat machine version - 6 and I notice that grub.conf inst exists how this Linux machine know with which kernel to start? ( in case grub.conf not exists ) is it safe to ...
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1answer
31 views

How to print the latest kernel version from grub.conf on Linux 7

On Linux 5 and 6 I can print the /etc/grub.conf How to verify the latest kernel version on Linux 7? , like we do on Linux 5 and 6 from grub.conf #boot=/dev/sda default=0 timeout=15 #splashimage=(hd0,...
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102 views

Unable to compile Linux Kernel 4.7-rc2

I was trying to compile Linux Kernel from source. I've compiled the kernel previously and never got any error. But this time I am facing an error. The error is CHK include/generated/asm-...
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16 views

Package additional in-tree modules

Targeting an up to date Fedora whose kernel unfortunately lacks a module: Is it possible to package the module (using kmod or whatever existing infrastructure), so that the module package has the ...
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1answer
328 views

Too many rcuos and rcuob processes in my VM

I am running CentOS 7.2 (3.10.0-327.18.2.el7.x86_64) as VMware guest with 2 cpu and 6 GB RAM on my Lenevo W540 iCore 7 having 32 GB RAM. I see 128 processes each for rcuos and rcuob in my VM. This ...
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1answer
54 views

Update kernel on ARM device

How can I update the kernel of my ARM device? The device I have been using is A20-Olinuxino LIME board, withDebian GNU/Linux 7.6 (wheezy) image booted from NAND. The uname -a command displays 3.4.102....
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65 views

Debian installation does not boot, shows iwl3945 0000:03:00.0: Could not read microcode: -12 error repeatedly instead

When trying to boot my Debian laptop, I encountered this error: May 31 06:59:44 Termina kernel: [28753.081242] iwl3945 0000:03:00.0: Direct firmware load failed with error -2 May 31 06:59:44 Termina ...
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2answers
235 views

extract Embedded initramfs

I have a kernel in which one initramfs is embedded. I want to extract it. I got the output x86 boot sector when I do file bzImage I have System.map file for this kernel image. Is there any way to ...
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1answer
45 views

qemu infinite loop on boot

I'm currently trying to set up a virtual machine emulating a ARMv7 Cortex-A8 on a x64 host running qemu. I've got a zImage which was built with the realview defconfig and a rootfs in cpio format. ...
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1answer
2k views

What does “DMA: Out of SW-IOMMU space” error mean?

First the link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1060268 Since this affects the kernel and other Distros, what does this type of error mean and why it happens?
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49 views

Updating kernel: vmlinuz in /boot not being created by DNF

Brand new F23 install, trying to update the kernel. I did lose power during the first round of dnf update and have to go clear out a bunch of conflicts that dnf kept reporting. It's possible I removed ...
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0answers
46 views

Possible slab memory leak related to bio and btrfs?

I'm currently running a rebuild on a btrfs NAS (~20TB) that had a drive failure. It's going to take a few days. My problem is about once every 24 hours the RAM filled up and the kernel starts killing ...
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1answer
38 views

Push firmware files in ath10k to Debian firmware-atheros

I would like to quote wireless.wiki.kernel.org: The ath10k firmware images are available from linux-firmware.git which all common Linux distributions should install by default. Latest firmware ...
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40 views

Partitioning (format) problems with LiteOn PCIe SSD

I recently got a HP Z Book 15 g2. That model has two disks, one of them (in my model) is a LiteOn PCIe SSD (Liteon CX1 JB256 HP). I want to install Linux on that particular disk. First, I tried with ...
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1answer
21 views

How to find a specific patch for a kernel file

I've been debugging an issue in my linux kernel and have found a fix for the issue. Checking cross reference, I can see that the fix was applied to that file between kernel version A and kernel ...
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1answer
2k views

how to make LVMs at available boot? kernel panic - dracut cannot find logical volumes after kernel upgrade in CentOS 6.6

I have a centoOS 6.6 vmware vm that I ran yum update on which upgraded the kernel after reboot, I started getting this: dracut Warning: No root device "block:/dev/vg_myhost/lv_root" found dracut ...
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1answer
49 views

psmouse kernel module recompiling

I have a ultrabook and its touchpad doesn't work. Linux mike 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt25-1 (2016-03-06) x86_64 GNU/Linux touchpad doesn't work and it is also not listed in output of ...
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1answer
188 views

Centos 7 not loading latest kernel at boot

By default, centos 7 comes with kernel version 3.10.x. After installation of centos 7, I have upgraded kernel to 4.6.x that is latest stable version. My system is remote. First, it is very expensive ...
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1answer
87 views

insmod: cannot insert './intrpt.ko': Function not implemented

I'm writing a kernel module that receives interrupts for mpc8308 (PowerPC) board. when I make the code for Ubuntu and my current version of kernel it works well with interrupt of keyboard, but when I ...
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2answers
151 views

scripted configuring of a linux kernel

Given a list of kernel features, I want to create a minimal linux configuration supporting all given features (and the corresponding dependencies) but nothing else. Is there a way to create a ...
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1answer
345 views

How to switch arch linux to lts kernel?

I'm running a headless server installation of arch linux. The high rate of kernel upgrades caused me some maintainance headache and I therefore wish to switch to the lts kernel. I already installed ...
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41 views

Linux + what are the steps use the oldest kernel version in place of the current

I have Linux red-hat 5 version I want to reboot the machine with the previous kernel - 2.6.18-408.el5 so I set the default to 1 but before I will reboot the machine to startup with the older kernel ...
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1answer
25 views

Packing a bootloader as kernel image

Can a bootloader (lets say lilo) be packed as a valid zImage to trick other bootloaders to chainload another bootloader? Sorry about my english and excuse me if I am not clear enough.
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How to remove all old kernels except the two latest

The following command deletes all kernels except the latest: package-cleanup --oldkernels --count=1 Does the following command delete all but the two latest kernels? package-cleanup --...
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1answer
369 views

Linux kernel 3.10.0-123.4.2 processes [flush] aren't present

I am using CentOS 7 with "3.10.0-123.4.2.el7.x86_64" version, but I don't know why the kernel threads named flush aren't present in this kernel version. I tried to look in the kernel change log, but ...
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1answer
951 views

Error compiling buildroot

I updated my buildroot for the version "2014.08" (stable version) and I updated the Kernel version (3.12.26) of my project, when the buildroot try to build the linux-headers-3.12.26 package, occurs ...
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1answer
71 views

Invalid Build path for driver creation

I wanted to create a simple Hello world driver as in here: Page2 and compile it with Makefile: obj-m := hello.o all: make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules clean: ...
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2answers
51 views

Why should not I update to most recent kernel immediately after release [closed]

Question intended for system administrators. Consider system running a old but working kernel and all the required functionality is available. (Ubuntu 12.04 LTS specifically with kernel 3.2) Then a ...
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1answer
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Can I start the VM in openVZ once the checkpoint is completed during vzdump?

I have a VM with huge amount of data, close to 800GB. I was taking a vzdump of this VM. During the vzdump, openvz suspends the vm and does a check point and does a final sync of data before completing ...
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4answers
8k views

How can I write to dmesg from command line?

I'd like to write a statement to dmesg. [How] can I do this?
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1answer
46 views

How do I run the Linux kernel?

I'm reading Robert Love's Linux Kernel Development in order to learn more about, well, Linux kernel development! But in Chapter 2: Getting Started with the Kernel, I'm instructed to download and ...
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1answer
28 views

Missing NIC in CentOS 5 - AsteriskNow 1.7.1

So I have two nics, but I can't get the second to load, here is the output from lspci -vvv 04:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network Connection Subsystem: Super ...
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2answers
57 views

How can strace monitor itself?

I have a Hypothetical Situation. (1) Let us say we have two strace Processes S1 & S2, which are simply monitoring each other. How can this be possible ? Well, in the command-line options for ...
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1answer
49 views

Compiling a kernel on STLinux

I have recently accessed STMicroelectronics Base Distribution with BusyBox v1.18.2, built-in shell. I read all the information on STLinux documentary regarding my problems, and followed all the steps....
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0answers
110 views

No perf (linux-tools) for kernel 4.5.2

When I first installed 16.04 LTS, at kernel 4.4.0, I had a decent battery life of about 3 hours average, but I upgraded to 4.5.2 to solve the suspend problem and some other issues, and now it's less ...
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1answer
68 views

Linux red-hat + kernel patch update

I need to run the yum update on my Linux redHat machine during the yum update , I sow that yum perform some patch kernel update therefore I little worry to perform a reboot , because the patches of ...
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1answer
81 views

Remove the new kernel

I was working without any problem and one day the computer didn't start he said that there is a problem in the Xserver , so I connected to my computer through ssh and reinstalled xserver-xorg ,xserver-...
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1answer
175 views

Unable to boot after updating the kernel rhel 6.7

I am having a Red Hat 6.7 running on VM which I updated with the latest version kernel-2.6.32-573.26.1.el6.x86_64. but after this update I received the below error: kernel panic-not syncing: VFS: ...
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3answers
280 views

Am I in the right direction for a linux os?

I compiled the linux kernel by downloading it from kernel.org, put it on my desktop, and opened up terminal. I changed to the linux-3.2.13 folder, typed mr proper. Then I use make menuconfig to ...
2
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1answer
599 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
56 views

Dracut failure when trying to boot Fedora with Qubes kernel

I would like to boot Fedora 23 Workstation x86_64 with a kernel from QubesOS 3.1. I have copied vmlinuz-4.1.13-9.pvops.qubes.x86_64 and initramfs-4.1.13-9.pvops.qubes.x86_64.img into the /boot ...
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0answers
92 views

Qualcomm Atheros AR298X not working with recent kernels

My wifi doesnt work. It used to when the kernel was 3.18 or less. If I have a kernel more than 4.1 it will not work. I would like to use ubuntu 16 and I don't want to downgrade the kernel. lspci | ...
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2answers
357 views

Cannot update new kernel for CentOS 7 although the server have space enough

I try to update kernel on my CentOS 7 but the yum say there is no space enough on /boot although /boot have 343 MB as show below: Filesystem Size Used Avail Use% Mounted on /dev/sda2 477M 105M 343M ...
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Kernel bug at at fs/dcache.c on XenServer

Yesterday on of our servers running Xen 6.5 restarted, in /var/log/messages I found following messages: Apr 29 11:52:59 server kernel: [7476681.051566] ------------[ cut here ]------------ Apr 29 11:...
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3answers
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Why is swappiness set to 60 by default?

I just read some stuff about swappiness on Linux. I don't understand why the default is set to 60. According to me this parameter should be set to 10 in order to reduce swap. Swap is on my hard ...
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3answers
139 views

How filesystem atomically writes a block to disk?

Block is an abstraction provided by filesystem, block size is integer multiples of disk sector size. Suppose a filesystem uses 4K as its block size, and the disk sector size is 512B, when the ...
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1answer
46 views

Designing a new Operation System

I want to design a new OS to learn more about how an OS works. This OS is only for educational purpose and I had a few doubts choosing its kernel. Is there any legal issue for using an Ubuntu kernel?...
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1answer
383 views

The meaning of Linux Kernel bug output

I have a quick, (maybe naive),question about Linux kernel's output. When I issue a command, the system (Ubuntu 12.04) freezes, the serial port output of this system is as follows: [ 373.805067] BUG: ...
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1answer
492 views

What does this key code qualifier mean?

I know that in general this means that I have a "bad disk". But I'm after a more specific reason for why I am getting these messages from the kernel: sd 15:0:0:0: [sda] Attached SCSI disk sd 15:0:0:...