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

learn more… | top users | synonyms

1
vote
0answers
27 views

Advice on printing in kernel [closed]

What is general advice on printing in kernel level? Lately, I need to print out some internal variables in various places. However, I use a naive way using printfk to dump the stuffs I need in log ...
1
vote
1answer
38 views

Why doesn't the Linux kernel prioritize interactive programs?

I've noticed that when running at 100%, things like GNOME become less responsive until I kill background tasks that are expected to take a long time, like compilation or downloading email. Why ...
1
vote
2answers
515 views

Cannot mount eCryptfs

I tried to install eCryptfs on my server to open an eCryptfs I did on my home computer. I got these errors. $ sudo mount -t ecryptfs /home/(place)/enc/ /home/(place)/enc/ Unable to get the ...
2
votes
0answers
28 views

File permissions for kernel have changed in OSX Yosmite, why?

I am working my way through the book Learning Unix for OSX Mountain Lion (I don't have access to the updated version for OSX), in which it demonstrates that using $ ls -l /mach_kernel should ...
2
votes
0answers
21 views

Significance of Linux kernel's default_console_loglevel

What is the significance of default_console_loglevel in Linux? Commonly I see it described as the default value of console_loglevel. However, what that means I haven't seen explained anywhere. ...
2
votes
2answers
102 views

Where is the RHEL7 kernel source code installed?

I install the Linux kernel source code RPM: [root@localhost ~]# rpm -ivh kernel-3.10.0-229.el7.src.rpm warning: kernel-3.10.0-229.el7.src.rpm: Header V3 RSA/SHA256 Signature, key ID f4a80eb5: NOKEY ...
0
votes
0answers
24 views

How to change the console_loglevel in linux?

I read at multiple places (e.g. here http://elinux.org/Debugging_by_printing), that you can change the console log level by echoing an integer to /proc/sys/kernel/printk. If that worked shouldn't the ...
0
votes
1answer
331 views

Update kernel to 4.1.1 in Ubuntu Mini

I'm using Ubuntu Mini 15.04 and I want to update the kernel to the latest 4.1.1. I've been looking online but there are so many different ways. I've tried some but always ran into some error. I am ...
1
vote
1answer
28 views

Number of Threads in Kernel

How can I get the number of threads in the kernel at specific sampling rate? I need to measure the utilization of the system directly by myself.
1
vote
1answer
33 views

Some questions regarding linux kernel external module build process

The Linux kernel documentation page for building external modules (https://www.kernel.org/doc/Documentation/kbuild/modules.txt) says this: === 2. How to Build External Modules To ...
1
vote
1answer
87 views

Where in the kernel /dev/kmsg gets initialized?

I'm trying to figure out at which point in the boot up process /dev/kmsg gets initialized and can thus be written. On my system the first line that occurs in dmesg is printk(KERN_INFO "Initializing ...
0
votes
1answer
58 views

Why Gentoo detects no network devices? [closed]

I've faced the problem installing Gentoo: after the installation is seems to be completed and LiveCD is extracted, network becomes unreachable: gentoo~ # ping 8.8.8.8 connect: Network is unreachable ...
0
votes
1answer
86 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 ...
1
vote
1answer
3k views

bnx2: Can't load firmware file “bnx2/bnx2-mips-09-6.2.1b.fw”

I just compile the kernel 3.10.19 from kernel.org Support for bnx2 is enable. On my server when I try to start the eth0 interface I got the following error : bnx2: Can't load firmware file ...
-1
votes
1answer
33 views

Remove branding from custom kernel

I have an assignment to build a custom kernel which removes all the drivers/plugins that are not needed and also remove any traces that it is Ubuntu's. Basically, my teacher wants us to strip it down ...
0
votes
0answers
3 views

How kernel will get control from u-boot in linux and who will un comnpress the image

I am basically Linux BSP. I want to know how u-boot will give control to kernel in android kernel or linux kernel. And how uImage will get uncompressed.
0
votes
1answer
265 views

What is a Kernel Routine ?

In another answer I met a short overview of the sections of the man pages: commands for $-User system call, that means evoking a function from the Kernel library call, that means evoking a function ...
0
votes
0answers
27 views

64bit Linux Mint on Dual Core Pentium 4 machine

I have a HP 530 desktop with a 3200Mhz Dual Core P4 processor, 4GB RAM and 1TB Sata HDD. I'm setup with Dual Boot Windows 7 and Linux Mint 17. Although Windows 7 64 bit loaded fine, Linux Mint 17 64 ...
1
vote
1answer
66 views

4G modem on an embedded 2.6.32.9 kernel on a Parrot AR Drone 2.0

I am attempting to compile support for a Huawei E3276 usb LTE modem for an embedded Linux/BusyBox installation on a Parrot AR Drone 2.0, which is based on kernel 2.6.32; however, I am running into ...
0
votes
0answers
50 views

I installed linux. And it doesn't recognize usb keyboard and mouse

When I boot computer with kernel 2.6, I can use usb keyboard and mouse. But If I use kernel 3.10, It doesn't work. / / kernel 2.6 $ lsusb Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 ...
0
votes
1answer
560 views

custom kernel and firmware loading

After I have compiled my kernel, and when I type make modules_install, not only are the modules copied into /lib/modules/ but also firmware is copied into /lib/firmware/. The following is the end of ...
1
vote
1answer
233 views

can't filter printk messages

I'm writing a driver and usually I implement my own log-level scheme. However, this time I figured that I would try to utilize the printk scheme that is built into Linux. I see that I can adjust the ...
0
votes
0answers
11 views

udev usb stick device list

we have 2 different yocto distributes. 1) ARM Kernel 3.10.53 2) X86 SMP Kernel 3.10.0 if we add a usb stick to the ARM system we get the different udev Messages. usb/usb_device usb/use_interface ...
0
votes
0answers
14 views

grsec installer compilation error

I'm looking to install grsec to enhance the security of my Debian box. When I run the unofficial grsec installer (re: https://github.com/rickard2/grsecurity-Debian-Installer) that was written to ...
2
votes
1answer
94 views

How to (really) disable NCQ in Linux

I implemented my own Serial-ATA Host-Bus-Adapter (HBA) in VHDL and programmed it onto a FPGA. A FPGA is chip which can be programmed with any digital circuit. It's also equipped with serial ...
0
votes
0answers
51 views

How to prevent Apper from removing older kernels when updating (installonly_limit)

Fedora usually keeps 3 kernel versions installed by default, so a kernel update will remove the oldest kernel version installed. However, in some cases it may be necessary to keep all kernels. In ...
0
votes
1answer
19 views

fakeroot make-kpkg buildpackage

When I run make-kpkg --initrd buildpackage with concurrency_level set to 17, all cores are at 100% according to gnome-system-monitor, when running the cc1-jobs. When I run fakeroot make-kpkg ...
1
vote
1answer
42 views

How the kernel can prevent a malicious program to operate?

If I write an x86 assembly program that tries to fetch and analyse all the addressable memory space. How the kernel can prevent this operation to be done? I am more familiar with small CPU ...
4
votes
1answer
66 views

How is raw mouse movement converted to /dev/input/mice content?

Raw mouse movement is generating some data and sent via USB. It is then getting processed somewhere and written into /dev/input/mice & supplied to GUI, etc. How is this happening? If I want to ...
4
votes
2answers
16k views

Command to install linux headers fails

I need to install my linux headers for an Nvidia driver install. But I get an error when doing so: peter@peter-deb:~$ sudo apt-get install linux-headers-$(uname -r) Reading package lists... Done ...
1
vote
1answer
32 views

Kernel driver for wireless adapter not in use

I recently installed Archlinux on my laptop, and as per the instructions on the Arch Wiki (https://wiki.archlinux.org/index.php/Wireless_network_configuration#Check_the_driver_status) I checked the ...
66
votes
5answers
96k views

How to reload udev rules without reboot?

How should one reload udev rules, so that newly created one can function? I'm running Arch Linux, and I don't have a udevstart command here. Also checked /etc/rc.d, no udev service there.
0
votes
1answer
31 views

Kernel current working directory and inode information placement

I'm reading some doc about UNIX but I don't understand two things: Why is important for the kernel to know the current working directory of the running process? Why not keeping the inode information ...
0
votes
1answer
60 views

Why ARM devices are not shipped with latest Linux kernel?

Wondering why ARM based devices like Raspberry Pi, Android phones, Routers etc. are not shipped with latest Linux kernel ? Is it simply due to lack of proprietary device driver support ? Like lack of ...
0
votes
1answer
56 views

HugePage Centos 6.6

Recently i install a CentOS 6.6, but when i tried to configure HugePages, i cannot see the common paths that i already using to configure hugepages in other Centos 6, but with 2.6 kernel series. So i ...
0
votes
1answer
56 views

Writing drivers for Oracle Solaris

I understand that Oracle doesn't provide sources for Solaris any more, as was done via OpenSolaris in the past. However, they do offer live CD images. How much does a system installed with such ...
0
votes
0answers
14 views

SystemTap log output to file

I want to log output from my SystemTap script to a file. But when I try to use the -o option like: stap -r $PWD --remote user@hostname -o test.txt -S 1 ./test.stp I can't find the log file. If I ...
0
votes
0answers
41 views

“Illegal instruction (core dumped)” in __lll_lock_elision() for various programs after suspend with initramfs (Arch/Manjaro)

I am getting random "Illegal instruction (core dumped)" on various programs in my Arch Linux system, since I ran some system updates. The crashes are quite random. E.g. sometimes "git status" crashes ...
1
vote
2answers
142 views

What does __ prefix before some kernel api's convey?

Why do some function calls in kernel specially have this prefix __ example: __init initialization(void) is __init a macro? What does this convey? Are these a special class of function calls inside ...
0
votes
0answers
17 views

How do I compile a custom Linux kernel to be optimized for Hadoop?

What can I do to configure a kernel to have resources that are optimized for Hadoop? I want to maximize the CPU and RAM availability for Hadoop. What can I remove from a traditional kernel if the ...
-1
votes
1answer
33 views

Grub Refuses New Kernel

so my Mint 17 hasn't been booting, and I tried reinstalling the kernel from a live USB drive. I followed the steps detailed in this guide to edit /etc/default/grub to accept the last saved kernel ...
2
votes
2answers
54 views

Linux kernel parameter “net.ipv4.tcp_workaround_signed_windows”

I am seeing some intermittent network issues when sending large amounts of data over a network and it has been suggested to me that setting this option to a 1 may possibly resolve the issue. ...
2
votes
1answer
530 views

Wireless constantly reconnecting on Ideapad running Arch

I just bought a new laptop, a Lenovo IdeaPad U330 touch, and after some struggle (with the Secure Boot stupidity) I have managed to install Arch Linux. I have configured my system, installed all the ...
1
vote
1answer
55 views

restoring grub mint 17

I'm currently trying to get my Mint 17 partition booting again. I tried to fix a booting problem with boot-repair and a live USB, but upon inputting the command sudo chroot "/mnt/boot-sav/sda7" ...
0
votes
1answer
44 views

What is the impact on system performance when kernel debug info is enabled?

In order to debug kernel or use tools like stap (https://en.wikipedia.org/wiki/SystemTap) kernel must be compiled with full debugging information included - namely option CONFIG_DEBUG_INFO has to be ...
0
votes
2answers
195 views

How can I replace the default kernel with an earlier kernel?

I am working on petalinux, Linux for xilinx FPGAs. The source code is here This Linux is having 3.x kernel, and I have been asked to change the kernel to some earlier release version. What are the ...
0
votes
1answer
33 views

bluetooth - btusb module remove stops bluetooth service

I just faced a strange issue; Every time after suspend the btusb module is kicked out the RAM (for some reason but its OK cause I can reinit it manually) but as a result the bluetooth.service must be ...
7
votes
1answer
122 views

NTP and NTPD Nanokernel

I had a couple of questions about the NTP Nanokernel as explained here: http://www.eecis.udel.edu/~mills/database/brief/nano/nano.pdf The big question is how does this Nanokernel manage to deliver an ...
1
vote
3answers
4k views

CentOS ELRepo Kernel installing VMware

Already installed VMware Workstation 9 on my Linux CentOS 6.5 Final with 3.10.40-1.el6.elrepo.x86_64 running kernel. When I open VMware Workstation, it asks me to locate the Kernel Headers ...
3
votes
1answer
55 views

How do I detect that my system has auto-rebooted after a kernel panic?

I'm using Linux in embedded systems, and want to configure the system to automatically reboot after a kernel panic. However, when the system comes back up, it's important for me to detect and log the ...