The kernel of operating systems popularly known as Linux, or sometimes GNU/Linux.
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12 views
How to strip unused architectures, drivers, etc from headers when building a custom linux kernel?
I am building custom linux kernel packages in a Ubuntu 13.10 amd64 environment usingapt-get source linux-image-$(uname -r)the debian way make-kpkg clean;fakeroot make-kpkg --initrd ...
-1
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2answers
45 views
Why does Linux have such terrible battery life compared to Windows?
On the same laptop, a given linux distribution always seems to have poor battery life compared to Windows. My old laptop (a Thinkpad X61) lasted nearly half as long when booted into Lubuntu than it ...
1
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0answers
28 views
Where is Linux kernel development headed? [on hold]
I regularly read development updates from various components of the Linux ecosystem. Of all these, the kernel is the one that seems least transparent to me.
Typical kernel release notes mention tons ...
3
votes
0answers
30 views
Kernel /proc ipv6 settings precedence
I'm about to connect our network to the IPv6 Internet and need to control the kernel ipv6 settings found under /proc. I know there are configurations for each interface, for all interfaces, and the ...
7
votes
2answers
347 views
How exactly does printk work internally?
I know printf needs help from the OS to do its job.
I also know printf does not work in the Linux source code as there is no library. And so we have printk for debugging.
How does printk work ...
0
votes
1answer
22 views
What is CONFIG_BASE_SMALL=0
Looking at the config file of Linux (that is generated prior to build) I found the following line:
CONFIG_BASE_SMALL=0
What does it mean? If I want my linux kernel to be as small as possible shall ...
-1
votes
0answers
30 views
How to buid linux kernel for the ubuntu? [closed]
Can anyone help me to customize the linux kernel for the ubuntu and put into another new disk that is attached to the oracle virtual box?
1
vote
0answers
72 views
Looking for a list of modules that are used during boot sequence
I'd like to use deferred init calls. This function allows to load modules in userland, that should actually be loaded during the boot sequence.
Just for testing I'd like to modularize as many entries ...
0
votes
0answers
38 views
How to cause memory fragmentation on a Linux based embedded device?
Hardware
ARM
What am I trying to do:
Answer: I am trying to create memory fragmentation on a Linux 2.6.31 based swapless embedded device.
Why:
Answer:I am trying to port some patches to Linux ...
2
votes
2answers
95 views
BSD Kernel Vs. Linux kernel? [closed]
I wanted to know in technical terms; what is the difference between BSD Kernel and Linux Kernel.
In Linux, we can download the source kernel then patch it and make and make modules it. Even we have ...
5
votes
1answer
102 views
Linux: What is a tainted kernel?
Under certain conditions, the Linux kernel may become tainted. For example, loading a proprietary video driver into the kernel taints the kernel. This condition may be visible in system logs, kernel ...
11
votes
3answers
2k views
Why there are many BSD systems but only one Linux kernel?
Why there are many BSD systems but only one Linux kernel?
I wonder why BSD was forked many times, but no such thing with Linux.
1
vote
1answer
37 views
Try to disable console output, console=null doesn't work
as mentioned above, I want to to completely turn off the console output, but putting console= or console=null in the kernel command line doesn't change a thing. When I enque quiet to the kernel ...
4
votes
1answer
84 views
How to relate a kernel config setting to the source files?
Here is an example that will explain better:
I have a selected the audio driver from the picture and i would like to browse through its source. How do i get to the path of the source files from ...
1
vote
1answer
16 views
Does perf includes some “graphing” abilities?
It's possible to create a bitmap or a vector image out of the data collected by the perf profiler under linux ?
1
vote
2answers
23 views
“select” vs “depends” in kernel Kconfig
What are the differences in dependencies between select and depends on in the kernels Kconfig files?
config FB_CIRRUS
tristate "Cirrus Logic support"
depends on FB && (ZORRO || PCI)
select ...
2
votes
1answer
38 views
Compiling Linux kernel for a router [closed]
I want to make an installable linux kernel that has routing enabled already. So anyone can install it on their machine, do some configuration as required, and machine will work fine for their routing ...
1
vote
2answers
47 views
Kernel Configuration: Which Processor Family to choose for 'Celeron M CPU 420' (Core Solo)?
I am trying to build custom kernel (version 3.12.13) for my old laptop and I am unable to determine the Processor Family from the provided list.
( ) 486
( ) 586/K5/5x86/6x86/6x86MX
( ) ...
2
votes
0answers
50 views
Why does the kernel boot faster with less memory allocated?
This is not a important question, I'm just curious. Something strange happened, which isn't quiet clear to me:
In the kernel command line, the amount of the memory can be set statically with the ...
1
vote
0answers
23 views
What are the linux kernel versions incompatibilities with btrfs?
I read that usage of a btrfs volume with a newer kernel can render it unreadable when that same volume is used with an older kernel. I have a mobile storage device that will be used by different linux ...
1
vote
3answers
55 views
Structure of GNU/Linux [closed]
I have some basic knowledge about Linux OS like it consist of Kernel.The kernel is core of Linux , It manages all processes, device drivers, and I/O.But My Question is what Linux consists of beside ...
1
vote
2answers
30 views
CentOS 6 with Linux-Libre kernel?
I understand that CentOS ships with nonfree blobs in it's kernel.
It seems that a "nonfree blob" free kernel exists, a.k.a. Linux-Libre. Is it possible to somehow get CentOS to use Linux-Libre ...
1
vote
0answers
15 views
KMS Terminal: How to disable second screen, or how to force a certaion resolution?
I have two screens with different native resolution connected to my Gentoo/systemd machine. since the VTs try to mirror the outputs, they do not use the whole size of the higher resolution screen. I ...
2
votes
1answer
36 views
Virtualbox complains that I don't have headers
I've installed Virtualbox (on Debian testing amd64)according to the wiki. But I get this error:
$ virtualbox
WARNING: The character device /dev/vboxdrv does not exist.
Please install the ...
1
vote
1answer
46 views
Debian/Ubuntu:How to compile a Linux kernel on one machine and use on other machines (same architecture)
Debian/Ubuntu: How to compile a Linux kernel on one machine and use on other machines (same architecture)?
I know how to do it on the same machine. But to use a compiled kernel other machines, is ...
0
votes
1answer
53 views
Which Linux distributions offer a stable release based on the 3.10 kernel?
I'm looking for a stable Linux distribution (preferably a well-known one) based on the 3.10 kernel. So far I have identified Gentoo as one such distribution. But I'm having trouble finding any others.
...
1
vote
0answers
18 views
Patching the kernel source through git
I'm trying to understand how the patching of the kernel source works.
I found the patch that I would like to try an apply on the following page. I found no .patch files that I can use to apply the ...
4
votes
0answers
53 views
Why are cgroups mapped differently on these two systems by systemd
I have two systems, both running customized variants of OpenSuSE 12.2 (Mantis), both running exactly the same kernel. I get two very different outputs of /proc/self/cgroup or /proc/$$/cgroup on the ...
2
votes
1answer
32 views
How much time do user => kernel mode transitions take?
I'm running Android-on-Linux, and communication of OpenGL ES calls over the QEMU pipe is very slow. QEMU pipes should be the fastest possible way to do this; could this be due to the repeated ...
1
vote
1answer
25 views
Getting correct perf version
I'm trying to run perf on my Ubuntu Precise box, which I recently upgraded to kernel 3.11.10-03111002 (manual install). The problem is that perf and kernel versions must match, and the requested ...
0
votes
1answer
64 views
Kernel 3.13 on Ubuntu ARM + Android kernel options compatibility
I've installed ubuntu 12.04 LTS with the kernel 3.13 on my ARM Samsung / Google Chromebook,using this tutorial :
http://www.virtualopensystems.com/en/solutions/guides/kvm-on-chromebook/
I have to ...
0
votes
1answer
37 views
A question about “VFS: Cannot open root device”
I'm using an embedded board ARM9 SAM9G25 which I want to boot from SD Card. When I build a linux kernel with a built-in rootfs (initramfs) then it's working as it should. Now I want to separate kernel ...
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0answers
5 views
how to get handle of already attached device in linux kernel? [migrated]
I am new to linux kernel driver.
I would like to know , how I can get the device handle from my own kernel module to an existing device which has already been registered and has a registered driver.
...
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0answers
187 views
kernel: “echo 0 > /proc/sys/kernel/hung_task_timeout_secs”
I got this errors in syslog. Any idea what does it mean? The system is running on Ubuntu 12.04, kernel: 3.8.0-35-generic #52~precise1
It looks to me like failure when trying to write to disk...
...
1
vote
0answers
16 views
Execute/invoke user-space program, and get its pid, from a kernel module [migrated]
I checked out Kernel APIs, Part 1: Invoking user - space applications from the kernel, and Executing a user-space function from the kernel space - Stack Overflow - and here is a small kernel module, ...
0
votes
1answer
44 views
Having difficulties mounting a rootfs for an embedded Linux
I want my Kernel to start a squashfs rootfs for an embedded Linux. The squashfs file is on a sdcard, therefor i put these parameters on it's command line:
console=ttyS0,115200
root=/dev/sdb1 rw ...
4
votes
1answer
51 views
Does using noatime on modern Linux make sense?
Starting from version 2.6.30 (which was released 5 years ago), Linux has the option relatime enabled by default. It means updates of file access time are very infrequent and prudent.
But I still see ...
2
votes
2answers
63 views
What is the difference between a patch which reverts a commit and a “reversed patch”?
Before May 6th, 2013, the fs/eventpoll.c file in the Linux kernel had the following line #1605:
if (!schedule_hrtimeout_range(to, slack, HRTIMER_MODE_ABS))
On May 6th, a commit changes this to ...
4
votes
1answer
44 views
What is not accessible from userspace?
I read somewhere (3.1.3) that there's a high ring (supervisor mode) and a low ring (user mode) and that some "things" can be run only from the highest ring.
What do they mean by "things"? I'd guess ...
4
votes
1answer
126 views
“Memory corruption detected in low memory” kernel messages?
I have some memory corruption detected in low memory messages. I have read about it here, but I'm afraid I can't really make anything out of the discussion. It does indeed happen when I ...
3
votes
1answer
27 views
How long do dentries stay in the dcache?
On Linux, when I create a new file and open it, an entry about it is created in the dcache's hash table, right? How long does that entry stay there? Does it get removed when nothing is currently using ...
0
votes
2answers
112 views
ck patch for Linux 3.13 [closed]
Does anyone have any news about the -ck patches for Linux 3.13 kernel tree?
I've checked here but there's nothing yet...
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votes
1answer
19 views
RHEL6: Failed Dependencies when installing a package
Hi I'm getting errors when forcing to install unixODBC package on RHEL 6 here is the following error: http://flic.kr/p/jBEFvP
I don't know where to get the following packages that were needed by the ...
0
votes
0answers
14 views
Issue with Hugepage reservation in linux
I have reserved hugepages for my process using below commands:
#echo 64 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
#mkdir -p /mnt/huge && mount -t hugetlbfs nodev /mnt/huge ...
0
votes
0answers
18 views
Recommendation for kernel config UEVENT_HELPER_PATH?
I use Gentoo Linux. Historically the kernel configuration UEVENT_HELPER_PATH to hotplug, then later to udevadm. Mine has been set to /path/to/udevadm, but I've had problems in the past on Gentoo ...
3
votes
1answer
40 views
Embedded Linux: Which machine directory to pick in /arch/arm?
I am just starting out with embedded Android drivers, so any help would be great. I haven't found a lot of resources online.
At the moment, I am working through a tutorial on porting a driver, and ...
0
votes
1answer
295 views
What do the kernel parameters acpi_osi=linux and acpi_backlight=vendor do?
I had troubles with the screen brightness control in my laptop and I fixed it by adding the acpi_osi=linux and acpi_backlight=vendorparameters to the filegrub.cfg.
I'd like to know what these ...
1
vote
2answers
37 views
why do I need to patch linux kernel to use pandaboard's spi?
I believe this question is a bit more general but here is how it goes :
I have read this article about using pandaboard's SPI, especially the part "Configuring and patching the kernel".
It says that ...
1
vote
1answer
58 views
Resolving executable user stack trace addresses in ftrace
I'm trying to obtain a user stack trace in ftrace, but for some reason, only my user program cannot resolve the addresses to symbols. First, the OS I'm using is:
$ uname -a
Linux mypc ...
10
votes
2answers
399 views
Observing a hard-disk write in kernel space (with drivers/modules)
Apologies in advance if this post is a bit dense/messy, but I'm having a hard time formulating it better... Basically, I would like to study what happens upon a hard disk write, and I'd like to know:
...
