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

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8
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4answers
241 views

decrease kernel boot log verbosity level

When my kernel boots, apart from the useful important information, it prints lots of debugging info, such as .... kernel: [0.00000] BIOS-e820: [mem 0x0000000000000000-0x000000000009d3ff] usable ...
1
vote
0answers
85 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 ...
1
vote
2answers
65 views

What hardware components do not require driver and why

This is a question that I had in my mind long ago but just now resurfaced back after reading this article. May I know why CPU and memory do not require driver? What other hardware components do not ...
1
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2answers
51 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
votes
1answer
52 views

xenix (sysv) file system doesn't support since kernel 2.1.21

xenix filesystem equvalent sysv filesystem, man mount says: Note that,cohorent, sysv and xenix are equvalent and that xenix amd cohorent will be removed at some point in future use sysv instead. ...
0
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0answers
331 views

Cpu and memory utilization is high in Aix

Hello everyone, I have problem with my CPU utilization I am using sar command to know my cpu idle % in that idle percentage is null and %sys %usr utilizing more, I am trying to check with ...
1
vote
1answer
61 views

Can grub load a kernel from HTTP?

Typically the kernel file is loaded via disk. Questions Is it possible to load it via HTTP/HTTPS? If so how?
0
votes
1answer
23 views

Production ready derivative from LFS

I've recently started delving into LFS and have been wondering if there are any popular or well-used distros that have been derived from LFS or BLFS. There are a few of completed projects on Github ...
0
votes
2answers
65 views

What is the command in linux, or a utility to know the current comand status (process status)

For example when I write telnet abc.wtf the telnet session begins saying trying to connect so and so IP, but is there a command that I can type in and know what is the current process happening to ...
2
votes
2answers
961 views

Looking for a distro that has linux kernel 4.0? [closed]

The computer I'm looking to upgrade to linux has a wifi card that isn't supported in linux but I read somewhere that it is supported in the 4.0 kernel. Because of this I can't install an old kernel ...
0
votes
0answers
46 views

lock_kernel declaration

I was trying to get usbip to work on my Mint netbook with Linux 3.2. The repo package doesn't have the require kernel module and the source won't compile. So I set off to fix it. I don't know the ...
3
votes
3answers
83 views

How do I check the running kernel version?

While troubleshooting a problem with my ethernet card, I've found that the driver I'm currently using may have some issues with old kernel versions. What command can I use to check the kernel version ...
2
votes
0answers
36 views

Compiling FreeBSD on OSX

I currently have the source for the FreeBSD kernel. I want to compile it and create an iso image, on my OSX 10.9 computer. Can this be done? Do I need any other tools?
0
votes
0answers
144 views

4.2 kernel build, missing version.h

I have installed a 4.2 vanilla kernel on Kali Linux 2.0 and prepared the kernel source with make clean prepare I then copied the source to the /usr/src/linux-4.2 directory. And this is symlinked to ...
2
votes
0answers
29 views

Is information security less hard in an open source system? [closed]

In the excellent article Why Information Security is Hard - An Economic Perspective, Ross Anderson poses that: ... you can make the security critical part of the system small enough that the bugs ...
1
vote
2answers
108 views

On page fault, how does Unix determine if the faulting address is in swap space?

When a page fault occurs for a virtual address for any process how does the linux/unix operating system determine whether that page (of that virtual address) was swapped previously present in memory ...
1
vote
1answer
69 views

How to find out what distros are using particular Linux version?

Given a distribution and its version, I can find which version of kernel it uses, e.g. for Ubuntu they are listed here, and for currently supported versions of Fedora they are here. In general, ...
1
vote
0answers
42 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 ...
1
vote
0answers
19 views

Is there something like “make localmodconfig” that detects *all* your hardware?

I understand that Linux's "localmodconfig" target looks through all your loaded kernel modules and produces a .config file that enables those modules. This is nice, but what about hardware whose ...
3
votes
0answers
93 views

ABRT report says “irq 19: nobody cared”, but why?

Every couple weeks, I need to reboot my system. When I do, and enter as root in the terminal, the following message (in some variation) appears: ABRT has detected 3 problem(s). For more info run: ...
0
votes
0answers
167 views

Kernel config for HP Stream 13 (booting from emmc disk)

I'm trying to install gentoo on hp stream 13 device and i am unable to boot up system from the emmc hard drive. Before trying gentoo on this device i have successfully installed debian, which clearly ...
0
votes
0answers
14 views

Recompile the kernel changing only one option

I've already built a custom kernel based on the mainline 4.1.6. Now I want to disable CONFIG_ACPI_I2C_OPREGION The kernel build is not very short, so I'd like to rebuild only the parts affected by a ...
0
votes
1answer
67 views

How can I update the kernel and initrd images in EFI boot loader?

I have successfully installed the EFI boot loader (using ELILO) but I am unsure how to actually keep the kernel images up to date. Can you help me understand the process please? Thanks. ...
1
vote
1answer
28 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
117 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 ...
0
votes
0answers
86 views

scripts/checkpatch.pl: Warning: consider using a completion

I'm currently writing a kernel driver that involves moving large amounts data from userspace to or from a peripheral, via a ring of bounce buffers. The buffer completion callback ups a semaphore, and ...
1
vote
0answers
56 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 ...
2
votes
0answers
28 views

What is “state-object” in cgroups

I am gathering some idea about lxc, kernel name spaces and cgroups. While reading man lxc-cgroup, i find : lxc-cgroup gets or sets the value of a state-object (e.g., 'cpuset.cpus') in the ...
0
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0answers
59 views

Stack pointer of the interrupt stack

Linux kernel has separate stacks for user mode and kernel mode process and also some special stacks. One of this special stacks is interrupt stack with the size 16 kilobytes placed in the ...
0
votes
1answer
56 views

Linux modules take a lot of space [closed]

I'm using the 4.1.2 mainline kernel. The package with image and all modules has 207 MB of installed size. I built a patched 4.1.6 kernel, taking the config from the current kernel and now the drivers ...
0
votes
1answer
35 views

Does MySQL processes run in user or kernel modes?

I try to count IOPS and I/O size with SystemTap script and use MySQL to be workload. I found mysqld doesn't call systemcall but mysqld has read/write on VFS. So, do MySQL processes run in user or ...
0
votes
0answers
158 views

Error while trying to compile/install kernel, 4.1.6 on Ubuntu 15.04

I'm trying kernel compilation in Linux for the first time. I'm using the guide here to learn the basics. I'm able to pull the source code from the git repository, and can compile it. However, I run ...
0
votes
0answers
25 views

X stopped working after a kernel update

My system is a laptop with Ubuntu 14.04, with an Intel CPU and Intel + Nvidia GPU combo. After one automatic kernel update, the GUI stopped working. It shows a blue loading screen with a spinner, up ...
56
votes
11answers
5k views

What's the philosophy behind delaying writing data to disk?

In Linux, a finished execution of a command such as cp or dd doesn't mean that the data has been written to the device. One has to, for example, call sync, or invoke the "Safely Remove" or "Eject" ...
0
votes
1answer
106 views

how to set i2c bus to soc audio codec

I'm working on an audio codec driver for cs4245 device. It's controlled by i2c. I have 2 hardwares (devel-board), one of the them has the codec attached to i2c-1 and another to i2c-2. The first one is ...
0
votes
2answers
1k views

How to add a system call in linux kernel 4.x

I'm trying to add a system call using linux kernel 4.1.6 but all the documentation I can find is for older versions. Does anyone know how it's done in the newer kernels or have any good references? ...
1
vote
0answers
25 views

how practical the number of cores in Android

I've often wondered how practical the cores usage in Android smartphone. I'm asking here because Android is based on Linux. I'm looking from technical perspective. The articles that I've read so far ...
1
vote
1answer
158 views

Does this bug indicate an error in my btrfs filesystem of simply a bug in the 4.2.0-RC5 kernel?

I'm not sure this is the right place to ask this... I have been running a pre-release kernel (4.2.0-rc5) and yesterday had a possible disk error on my 6-disk raid-1 btrfs filesysystem. While trying ...
0
votes
0answers
33 views

How do I track down why my system is unstable?

I am experiencing a problem where I use Chrome on my X220 with CentOS 7 (kernel 3.10.0-229.el7.x86_64). It begins when I've been surfing Chrome for a bit and have a few tabs open. Chrome may just ...
1
vote
1answer
44 views

What module in the kernel that inform the DHCP client to start DHCP negotiation?

DHCP client is a process instead of kernel code. How the DHCP client know when to start sending DHCP discover message? Is it the IP module in the kernel that inform the DHCP client?
2
votes
3answers
121 views

login shell (bash) - how to we invoke a login shell

I know what is a login shell and the difference between a login shell and a non-login shell. But what puzzles me is how it is invoked. It is said that a login shell is invoked with a - as argument ...
0
votes
0answers
133 views

Status of UVC 1.5 support in Linux

My (Debian 8) kernel, 3.16.7 only detects the Logitech C930E webcam as UVC 1.0 (when it does support 1.5). Searching the Internet only throws up kernel patches, most of them from Pawel Osciak form ...
0
votes
0answers
111 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 ...
0
votes
0answers
14 views

How to compile a third party driver in to the kernal? [duplicate]

I am using Linux Mint 17.2 on Toshiba c640. As my LAN driver is no more functional, I am using a USB to LAN converter which was provided with some driver installation files. Every time i want to use ...
1
vote
1answer
190 views

How to compile a third party driver into the kernel?

I am using Linux Mint 17.2 on Toshiba c640. As my LAN driver is no more functional, I am using a USB to LAN converter which was provided with some driver installation files. Every time i want to use ...
0
votes
1answer
41 views

New Kernel does not automatically reconnect to network

I tried playing around with compiling my own kernel. Everything is fine so far, except for that one thing. Whenever I leave a wifi network or unplug my ethernet cable the system does not recognize, ...
1
vote
1answer
280 views

iptables - why do I get “Table does not exist (do you need to insmod?)”

I need to install some iptable ruels to block traffic that originates from a certain country, I found this script example on http://www.cyberciti.biz/faq/block-entier-country-using-iptables/ it works ...
2
votes
1answer
80 views

How does Linux kernel know that collisions occurred in Ethernet collision domain?

Let's say that I have a following network topology: Theoretical total(Tx + Rx) bandwidth for all four hosts in total is 100Mbps. Now if I execute Iperf in UDP mode in all four hosts simultaneously ...
0
votes
2answers
92 views

Windows Internals for Linux [closed]

I've recently been reading Windows Internals version 6 (from Microsoft Press), and found it thoroughly enjoyable. I'm now using Kubuntu on my work machine, and as such have some desire to learn a bit ...
0
votes
0answers
59 views

Test program to configure MPLS datapath in Latest Kernel 4.1.3

Latest Kernel supports MPLS datapath in kernel, However there is no test program, or any guide how to write user space program to configure a MPLS datapath in kernel. I browse the kernel code and ...