Tagged Questions

The kernel of operating systems popularly known as Linux, or sometimes GNU/Linux.

learn more… | top users | synonyms

1
vote
1answer
693 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
1answer
241 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
164 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 ...
2
votes
1answer
110 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 ...
-1
votes
1answer
40 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 ...
1
vote
2answers
98 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 ...
6
votes
2answers
1k 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, ...
3
votes
1answer
161 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: ...
2
votes
2answers
533 views

Enabling UTS Namespaces in the Linux Kernel

When configuring the Linux kernel, what are the advantages and disadvantages of enabling UTS namespaces? Would the new system be harmed if UTS namespaces were disabled?
1
vote
1answer
2k views

Understanding RCU when Configuring the Linux Kernel

I am configuring the Linux kernel version 3.9.4. I am being asked questions about RCU (seen below). Specifically, what are each of these and what are the advantages and disadvantages of enabling or ...
3
votes
0answers
198 views

How to set CONFIG_PREEMPT_NONE in RHEL 6.4 (linux)

I am trying to tune the RHEL6.4 Kernel to handle server style load for of my application. With RHEL 6 scheduler has been changed to CFS and with RHEL 5 my application works fine. I would like change ...
5
votes
2answers
480 views

mount options shown in /proc/mounts

IIRC then the mount options shown in /proc/mounts have changed. Some time ago acl and user_xattr were shown, now it seems that only noacl and nouser_xattr are shown if these features are turned off. ...
1
vote
2answers
3k views

Determine if reboot is required to update kernel?

I am running a server which runs on CentOS with cPanel (latest version) and I have it set to automatically update using yum. Since it needs to be rebooted in order to update the kernel (and possibly ...
2
votes
1answer
2k views

net.ipv4.conf.all.mc_forwarding: why is my access denied?

On Debian 12.04 LTS I am trying to access the key net.ipv4.conf.all.mc_forwarding by doing : sudo sysctl -w net.ipv4.conf.all.mc_forwarding=1 But every time I am doing this, I get the message ...
4
votes
3answers
2k views

how to get network QoS statistics in linux kernel?

Is there a way to get the bandwidth, delay, jitter collision, error rate and loss rate of a certain link through the interface on a local machine? let's say my machine is connected to a network via ...
2
votes
1answer
89 views

What are some of these directories in the Linux kernel src?

When I uncompress the Linux kernel source code from Kernel.org, there are many folders. I know what most of them contain and their purpose. However, I cannot figure out or find on the Internet the ...
15
votes
5answers
3k views

Can ps display only non kernel processes on Linux?

How can I ask ps to display only user processes and not kernel threads? See this question to see what I mean...
2
votes
1answer
54 views

Theoretical possibilities for cpu emulation built into boot-loader or kernel?

Is it a crazy idea to somehow make a blend of grub and qemu in order to boot linux kernels or any kernel of any cpu type supported by qemu or the built-in cpu? I know it might be impossible to detach ...
1
vote
1answer
104 views

Kernelpanic Fedora 18 with kernel 3.9.2-200

Since upgrading to kernel 3.9 I now get this error every time at start up: BUG: unable to handle kernel NULL pointer dereferences at (null) IP[<ffff8800ca93bfcd>] 0xffff8800ca93bfcc PGD 0 ...
7
votes
1answer
5k views

using devtmpfs for /dev

I have noticed the following option in the kernel: CONFIG_DEVTMPFS Device Drivers -> Generic Driver Options -> Maintain devtmpfs to mount at /dev And I see that it is enabled by default in ...
2
votes
1answer
492 views

I'm failing to set up a wireless Access Point (AP)

I'm trying to get this card to be an access point, and am failing. I tried various Ubuntu releases, and checked on both ARM and i386. The kernel version I used is 2.6.35, and there is no Network ...
1
vote
2answers
178 views

obtaining kernel build tree

Could anyone explain me what the kernel build tree is? What files does it include? How can I obtain it from a cross-compiled kernel source (e.g. 3.4.0)?
0
votes
1answer
1k views

Can't install Linux Headers on Debian 6

I don't understand why this isn't working (I'm stumped!); root@box:/home/user# apt-get install linux-headers-2.6.32-5-686 Reading package lists... Done Building dependency tree Reading state ...
0
votes
2answers
597 views

File system CRC check

I know that before running the kernel, u-boot (the boot loader) will check the kernel image CRC. Only if it is correct it will go further, else it will give a "Bad CRC" error. I want to do same thing ...
0
votes
1answer
83 views

Linux snapshotting issues [duplicate]

Is there any way to deal with incoming writes while a backup is in progress in linux. Example, you are writing to your sql database and lvm snapshotting at the same time. This will result in corrupted ...
1
vote
1answer
220 views

compressed and uncompressed kernel on an embedded device

I have been using several different embedded boards that store kernel, init files, filesystem, etc. on partitions of a (micro)SD card. I notice in the example usage or instructions that compressed ...
3
votes
2answers
589 views

Why does Linux 3.2 kernel (Debian backport) hang during boot?

I wanted to upgrade the Linux kernel on my Debian wheezy (stable) on Thinkpad T60. I installed linux-image-3.2.0-0.bpo.4-686-pae, version 3.2.41-2~bpo60+1. The problem is it hangs during boot, just ...
3
votes
2answers
10k views

What does “INFO: task XXX blocked for more than 120 seconds” exactly mean on Linux?

I had this message in my kernel log : INFO: task XXX blocked for more than 120 seconds. I would like to know what it means technically: under what conditions does the kernel display this message about ...
1
vote
1answer
485 views

building/compiling kernel headers

I am compiling kernel 3.4 and 3.8 for different target devices. I would like to install compat wireless driver which requires kernel header. Could anyone tell me how I can compile/build the kernel ...
9
votes
4answers
5k views

Are FIFO, pipe & Unix domain socket the same thing in Linux kernel?

I heard that FIFOs are named pipes. And they have exactly the same semantics. On the other hand, I think Unix domain socket is quite similar to pipe (although I've never made use of it). So I wonder ...
3
votes
1answer
382 views

Real mode and loading linux kernel confusing

As far as I know, protected mode will be activated in kernel and in grub stages it still real mode. My misunderstanding is: In real mode, total memory available for use is less than 1MB but how grub ...
2
votes
3answers
398 views

files in /proc/$PID (e.g. ssh-agent, Chrome) are not owned by user but by root

I am just answering another question here :-) and thus had a look – wanted to have a look at /proc/$PID/fd of ssh-agent in order to find out which socket it uses. But I can't. I am quite surprised to ...
2
votes
3answers
138 views

What considerations need to be made when choosing the version of kernel for an embedded device?

I have used buildroot to successfully create a kernel, root file system and cross-compilers to enable me to write application code to run on an embedded device. Currently I have no need to write ...
2
votes
1answer
59 views

What is the relation between the Linux device drivers “domains”?

As I'm reading about the Linux device drivers and power management API I keep encountering terms like "system level", "subsystem", "platform", "class", and so on. What is the relation between them? ...
0
votes
0answers
66 views

Decreasing mouse sensitivity at kernel level

I have developed a custom-GUI Server, which runs on virtual console of Linux.For mouse-handling purpose, it reads the mouse device file /dev/input/mice and retrieves the event data and updates ...
3
votes
1answer
1k views

How do you compile your own kernel on a RHEL6 system?

In RHEL6, the kernel is 2.6.32. What is the procedure to compile your own kernel?
1
vote
1answer
84 views

Does alsa depend on the kernel version?

Lately I had nothing but trouble with my sound setup. The full chain looks like this: alsa (pulse plugin)-> pulseaudio (jack plugin) -> jackd -> firewire soundcard This works fine, except ...
3
votes
2answers
1k views

How do I extract the filesystem image from vmlinux.bin?

jor1k ships a vmlinux.bin. I think there is an initrd inside, cause I don't know where else it would be. I am trying to extract the filesystem image so I can change it, but I don't know how to. I ...
78
votes
5answers
14k views

Why isn't Linux embraced as the official GNU kernel?

While I knew for quite some time the existence of Hurd, and its mission as the official GNU Operating System kernel, I was wondering how come Linux is not embraced as the official GNU kernel over the ...
1
vote
1answer
402 views

Determine whether kernel built-in driver supports a device

I'm trying to find a way to accurately determine whether all the hardware on some system has a valid driver installed either via a kernel module or built-in to the kernel. I'm working with RHEL 5.5 ...
1
vote
2answers
260 views

Does linux modules/drivers belong to kernal space or user space

Some articles say that modules/drivers belong to kernel space as it take part in forming the kernel; (reference: http://www.freesoftwaremagazine.com/articles/drivers_linux) While others say that ...
0
votes
1answer
143 views

“Acpi-State” in slabtop's output gets increased — what is it? Is it a bug?

Since boot it gets increased occupying even more RAM than anything else: Active / Total Objects (% used) : 680608 / 719176 (94.6%) Active / Total Slabs (% used) : 17390 / 17390 (100.0%) ...
5
votes
5answers
3k views

How to determine which module taints the kernel?

My kernel keeps panicking when connected to a certain wireless network. I'd like to send a bug report but my kernel is apparently tainted. From /var/log/messages: Apr 17 21:28:22 Eiger kernel: ...
8
votes
2answers
128 views

How should I solicit feedback from a tree maintainer for patches sent to the lkml?

I have submitted a patch to the linux kernel that has gotten several reviews and gone through a couple iterations on the mailing list. It has been ACKed and reviewed by two developers, but they say ...
1
vote
2answers
141 views

how to uniformly execute benchmarks on linux

I am doing project on adapting Linux for scalable multi core architecture. I am testing Linux's performance with benchmarks. When I am running the benchmarks in the system then other programs like ...
2
votes
1answer
847 views

sigaction(7): semantics of siginfo_t's si_code member

I've got a long-running program (becomes a daemon with daemon(3) call) that exits on Signal 11 (Segmentation Violation) every so often. I can't tell why. So, I wrote a SIGSEGV handler, set using the ...
2
votes
2answers
1k views

GRUB2 and kernel vga= parameter

According to the documentation, use of the vga= kernel parameter is deprecated as of GRUB2. The fact that some newer kernels don't seem to support it anymore on certain adapters is of no concern as ...
2
votes
1answer
344 views

Address types used in Linux

I am trying to understand the Memory address types used by the Linux kernel, which are User virtual address Physical address Bus address Kernel logical address Kernel virtual address I understood ...
0
votes
1answer
97 views

What are the other congestion control algorithms specially designed for lossy Wireless Networks like LTE and WiMax?

I am trying different congestion control algorithms for getting maximum throughput and minimum delay across my setup for TCP flow.Please suggest other available algorithms apart from Veno, ...
0
votes
1answer
204 views

Install x11 on my own linux system

I have developed my own tiny linux file system using buildroot and busybox. I used linux-2.6.38.8 kernel configured and cross-compiled for target system(X86) according to needs.Now the filesystem is ...