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

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2
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2answers
345 views

Do Solaris 10 and 11 still use slab allocation for their kernel memory allocator

If not, what do they use. Please provide a source.
2
votes
0answers
101 views

How to find where driver.mod.c links to?

I'm trying to port the webcam composite gadget from kernel 2.6.37 to 2.6.32. I don't have a choice on this since I depend on other drivers and a SDK which only compile for this version. My train of ...
6
votes
2answers
1k views

Does Linux kernel 3.x use the CFS process scheduler?

Does the latest version of the Linux kernel (3.x) still use the Completely Fair Scheduler (CFS) for process scheduling which was introduced in 2.6.x ? If it doesn't, which one does it use, and how ...
4
votes
1answer
1k views

How can I use netconsole to help solve a kernel panic?

When I try to use a raid as root, my system panics. I want to read the kernel output right before the panic, but can't scroll up. After Googling a bit, I wanted to try netconsole. but I get no output ...
9
votes
2answers
290 views

How am I supposed to keep up with kernels as a developer?

I'm developing for a specific TI ARM processor with custom drivers that made it to the kernel. I'm trying to migrate from 2.6.32 to 2.6.37, but the structure changed so much I will have weeks of work ...
2
votes
1answer
716 views

High memory (user space) and highmem (kernel space)

Each process has 2 memory area: User space (high memory) and kernel space (low memmory). In the kernel space, are the first 896 MB used for mapping kernel code (not fully 1 GB)? This means, when a ...
2
votes
0answers
393 views

Can I apply real time Linux kernel patch on Android kernel?

I would like to apply real time patch on the Android kernel (given I've found Kernel patch for corresponding Kernel version). Is it possible or should I create a patch specifically for the purpose of ...
4
votes
1answer
389 views

When should I keep debugging symbols in kernel modules?

When installing kernel modules, I have the option to strip out debugging symbols using INSTALL_MOD_STRIP=1. This saves significant disk space. Does it also save memory? Why should one keep the ...
5
votes
2answers
1k views

Booting a newly compiled linux kernel

I have started reading the book Essential Linux Device Drivers. I am following the process for compiling and booting into a new kernel. However I am unable to boot into the newly compiled kernel - I ...
2
votes
1answer
255 views

Automatically update a Debian system

I want to automatically update a Debian system (actually Debian Wheezy on Raspberry Pi, though that shouldn't make much a difference). I've already seen that there is cron-apt, probably a good choice, ...
5
votes
1answer
3k views

How do I convert a kernel .config file from 32-bit to 64-bit?

At this page you can download a configuration file that lets you target a particular notebook architecture during the compilation of a new 32-bit Linux kernel. I need a 64 bit version. What do I ...
0
votes
1answer
2k views

How can I generate /proc/vmcore?

I want to practice with makedumpfile. However, it needs /proc/vmcore which is the memory image of the currently running kernel. Also, reading the man page of makedumpfile, we also need 2 kernels: ...
1
vote
1answer
135 views

Choose kernel for specific hardware

I have old system with an AMD Athlon 1,2 GHz processor and [SiS] 65x/M650/740 graphics (output from lspci). Recently I discovered on a german ubuntu page that since version 10.10 some older ...
1
vote
1answer
834 views

Is Native Language Support (NLS) kernel support still necessary?

Does ext4 / cifs system need kernel NLS support ? I'm not sure if it's being handled by user-space program (decoding / encoding) ?
4
votes
2answers
2k views

How to know if a network interface is tap, tun, bridge or physical?

As far as i know, there are 4 main types of network interfaces in linux: tun, tap, bridge and physical. When i'm doing sys admin on machines running KVM, i usually come accross tap, bridge and ...
1
vote
1answer
245 views

Edit the .config file when en/disabling a particular option like CONFIG_CPU_FREQ?

From here: http://www.xenomai.org/index.php/FAQs#Which_kernel_settings_should_be_avoided.3F Which kernel settings should be avoided? Note that Xenomai will warn you about known invalid ...
6
votes
1answer
1k views

WARNING: modpost: Found 10 section mismatch(es)

Is this error message something that I should be worried about? linux-y3pi:/usr/src/linux-2.6.38.8 # make modules scripts/kconfig/conf --silentoldconfig Kconfig CHK include/linux/version.h ...
4
votes
1answer
1k views

How to know whether the Linux driver for the real-time network device was built into the kernel?

From here: http://www.xenomai.org/index.php/RTnet:Installation_%26_Testing#Debugging_RTnet The Linux driver for the real-time network device was built into the kernel and blocks the hardware. ...
1
vote
1answer
289 views

install 2.6.32.59 on squeeze

I'm suffering from a kernel bug in a production environment. The problem isn't causing a complete outage, but it's degrading service. These are soft lockups. I'd like to try a newer kernel, ...
3
votes
1answer
472 views

Is it necessary to enable CONFIG_USB_OHCI_HCD , when there's only USB 2.0 ports

Is it necessary to enable CONFIG_USB_OHCI_HCD on a system that has USB 2.0 port only ? I'm not sure those devices present , e.g bluetooth , camera use that driver ? Bus 001 Device 001: ID 1d6b:0002 ...
1
vote
1answer
277 views

Where is CONFIG_APM in kernel - 2.6.38.8

From here: http://www.xenomai.org/documentation/xenomai-2.6/TROUBLESHOOTING Q: Which CONFIG_* items are latency killers, and should be avoided ? ... APM: The APM model assigns power management ...
1
vote
1answer
96 views

ACPI (Advanced Configuration And Power Configuration) not present on 2.6.38.8?

I need to disable some parts in ACPI, but it is simply not present in kernel 2.6.38.8 (downloaded as a tar from net)? I can see the option in kernel 2.6.34-12 (default on OpenSuse 11.3), but not in ...
0
votes
1answer
533 views

buildroot/busybox: launch bootchartd on startup

I built a custom linux image using buildroot and busybox. To speed up the boot process I'd like to use bootchartd (built-in version of busybox) to profile the process. However bootchartd is not ...
1
vote
1answer
151 views

how to enable sound support in linux kernel without recompile?

I have recently compiled linux kernel 3.2. But at time of compiling in make menuconfig, I had disabled sound support. Now, I want to enable it without recompile it. I don't want to use stock kernel ...
2
votes
3answers
466 views

Why does Linux on sparc64 architecture use 32-bit pointers in user-space and 64-bit pointers in kernel-space?

What are the advantages of deviating from the norm; that is 64-bit pointers in both user and kernel space for a 64-bit architecture? Reference: http://lwn.net/images/pdf/LDD3/ch11.pdf (Page 2)
2
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0answers
609 views

Qemu doesn't boot kernel after “Uncompressing Linux… done, booting the kernel. ”

I've compiled qemu for s5pc110 (it's from http://gitorious.org/samsung-linux-platform/qemu, somebody had added support for s5pc110), version 0.12. But when I load the kernel: qemu-system-arm -M ...
30
votes
4answers
42k 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.
13
votes
3answers
2k views

Why don't you need to update drivers? (Or do you?)

In my life I've not once updated drivers on any of my Linux systems, though they have all been desktops. A friend was asking me why one does not need to update Linux drivers and I found myself unable ...
5
votes
1answer
580 views

Needs help on setting up kernel keyboard mapping

I already got the keycode from kernel, but acpi_listen won't recognize it in Arch Linux: # /usr/lib/udev/keymap -i /dev/input/by-path/platform-thinkpad_acpi-event Press ESC to finish, or Control-C if ...
1
vote
2answers
100 views

linux with 3.2.x kernel [closed]

Is there a major Linux distribution that uses 3.2.x kernel?
3
votes
1answer
2k views

vmlinuz and initrd not found after building the kernel?

After configuring and building the kernel using make, why don't I have vmlinuz-<version>-default.img and initrd-<version>.img, but only got a huge vmlinux binary (~150MB)?
2
votes
1answer
322 views

Which edac module should I enable here?

I got a Intel(R) Core(TM) i5-2450M CPU @ 2.50GHz CPU here , not sure which module should be enabled for EDAC: Chipset: Inter Coporation 6 Series/C2000 , driver in use: i801_smbus
3
votes
2answers
1k views

How do I build the iptables kernel module for a loaded kernel?

I've built a kernel with loadable module support for various reasons, one of them the possibility to compile modules and load them without rebooting. This is supposed to be useful when I need a module ...
0
votes
1answer
1k views

Can the Linux kernel be compiled on Mac OS X 10.6.8?

I have a Macbook Pro and I want to build the Linux Kernel. Can I build 3.3.6 on my Mac? How?
3
votes
1answer
687 views

Do I have to list modules in both `/etc/mkinitcpio.conf` and `/etc/rc.conf`?

I've added few modules into mkinitcpio.conf. Are they automatically loaded at kernel boot or with udev if I don't specify them in modules list in rc.conf?
5
votes
2answers
2k views

VirtualBox guest: 16 CPUs detected but only 1 online

I am running VirtualBox (using the Qiime image http://qiime.org/install/virtual_box.html) The physical hardware is a 32 core machine. The virtual machine in VirtualBox has been given 16 cores. When ...
3
votes
1answer
111 views

What does CONFIG_IA32_AOUT do actually?

I'm running a 64bit kernel, already have CONFIG_IA32_EMULATION set, so do I still need CONFIG_IA32_AOUT enabled? From the help in menuconfig, I don't quite get it.
14
votes
3answers
7k views

How can I reserve a block of memory from the Linux kernel?

I have a device that needs a block of memory that is reserved solely for it, without the OS intervening. Is there any way to tell BIOS or the OS that a block of memory is reserved, and it must not ...
23
votes
1answer
2k views

High CPU usage with CFS?

I asked a previous question to try and isolate the source of an increase in CPU usage when moving an application from RHEL 5 to RHEL 6. The analysis that I did for that seems to indicate that it is ...
2
votes
1answer
635 views

Learning how to build my own linux kernel

Reference - http://www.linode.com/wiki/index.php/PV-GRUB#Building_Your_Own_Kernel In order to work with Xen, a number of options that must be selected: CONFIG_PARAVIRT_GUEST=y CONFIG_XEN=y ...
4
votes
3answers
544 views

Does the linux kernel (specifically 2.6 onwards) have any recursive function?

Given the limited fixed size of kernel stack, my guess is that although theoretically we might have a recursive function if its recursion doesn't go too deep, pragmatism would suggest to do away with ...
8
votes
1answer
3k views

Isolating cause of higher CPU usage on RHEL 6 vs RHEL 5

I'm currently looking to move our system from RHEL 5 to RHEL 6, but I've run into a snag with unexpectedly high CPU usage on the RHEL 6 machines. It appears that this may be due at least in some part ...
3
votes
1answer
716 views

Hyperthread and processors Clock, Size, and Capacity

When I enable hyperthreading, CPU size and capacity decrease to about half the non-hyperthreaded value. Since most of my processes use only two cores, should I disable hyperthreading? lshw -C ...
6
votes
2answers
665 views

Asus X101H - Touchpad not recognized (want to disable while typing)

I have been struggling with this issue for a while and have done an exhaustive search for answers here and elsewhere before posting this question. On my Asus X101H, the touchpad is not recognized as ...
2
votes
1answer
6k views

/lib/modules/2.6.37.6/build missing in linux puppy? what should I do?

I am new to linux as of yesterday. I'm using linux puppy to try to get the most out of a 10 year old, slow laptop. I installed it fine, no problems there, but as soon as I try to use my usb dongle's ...
6
votes
1answer
579 views

Linux kernel 3.3 power regression

I am using Fedora 16 in my DELL n4110. I recently upgraded the kernel from 3.2 to 3.3. In contradiction to the official claim, my system still drains battery as hell. It only provides 1:30 to 2 hrs of ...
7
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2answers
2k views

How can you determine which process scheduler is being used? [duplicate]

I.e. is it the O(1) scheduler, the CFS scheduler, or an older one?
1
vote
2answers
2k views

How to add boot parameters in arch linux

I want to add i915.i915_enable_rc6=1 as a kernel line as described here but I'm unsure where/how exactly.
0
votes
0answers
472 views

adding system calls to kernel without recompiling during implementation

Could anyone tell me if it is possible to add several system calls to the linux kernel (version 2.6.35) and not have to recompile the kernel each time I change one of their implementations (i.e. ...
2
votes
2answers
607 views

Joli OS on ARM devices

I didn't really know where to ask this question, so since Joli OS uses the linux kernel and they don't seem to have a forum here I go. All the official information I could gather says it doesn't work ...