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

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1answer
210 views

Why is bzip2 needed in the kernel patch instructions?

This is from here. Extract the patch tar -xvzf /usr/src/web100-2.5.22-200810130047.tar.gz bzip2 web100/ web100-2.6.27-2.5.22-200810130047.patch Test the patch bzip2 -dc /usr/src/linux/web100/ ...
2
votes
1answer
1k views

Dump Page table layout (KERNEL CONFIG)

While configuring kernel for debugging found this option: CONFIG_X86_PTDUMP: Export kernel pagetable layout to userspace via debugfs Does this mean RAM page-table layouts ? any guides on how ...
2
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1answer
983 views

Where can I find information on Linux device driver parameters?

I want to work on Linux module programming (Device Drivers). And as a my college project I have to do profiling or benchmarking of a kernel modules based on various parameters. Everywhere I looked, I ...
4
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1answer
1k views

Booting without initrd

Is it possible to boot linux without a initrd.img ? I am planning to add default drivers as a part-of-kernel itself and avoid initrd completely. What are the modules that should be made ...
2
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1answer
1k views

Creating new initrd without installing kernel

How can i create initrd image for a new(experimental) kernel without actually installing it. (Existing tools to create initrd based on config and details from installed kernel.) Say i compile a new ...
9
votes
3answers
807 views

Memory size for kernel mmap operation

I'm interested in the way Linux mmaps files into the main memory (in my context its for executing, but I guess the mmap process is the same for writing and reading as well) and which size it uses. So ...
22
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4answers
3k views

Kernel Hacking Environment

I have been working in embedded OS like uCOS, ThreadX. While I have coded apps in Linux, now I’m planning to start learning Linux Kernel. I have few questions regarding the environment. Which is ...
4
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1answer
2k views

How to use the EXTRA_FIRMWARE_DIR kernel option?

I am using Gentoo, and I need to load an extra firmware to get my USB Wifi adapter work. I found an EXTRA_FIRMWARE_DIR kernel option, but I do not understand if it is used during compile time only or ...
5
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2answers
1k views

Benefiting of sched_autogroup_enabled on the desktop

I am running a 2.6.37 kernel with sched_autogroup_enabled set to 1. I am not certain that I am seeing the benefits of this patch since: I am launching my applications from the desktop; applications ...
3
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1answer
318 views

Linux kernel support for USB gamepads?

I've got an old Logitech USB gamepad that worked well under both Windows and Mac OS X. That is, the gamepad was totally "plug and play" for games run by a Super Nintendo emulator (SNES9X). Does Linux ...
3
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2answers
474 views

What are the kernel, the “GNU tools and utilities”, the shell and the Window Manager?

Among the many components of a Linux system, I find myself confused (as a newbie) about what exactly is the kernel or what is GNU's part. I understand some basic concepts of this, but where is the ...
2
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1answer
7k views

RAMDISK incomplete write error kernel panic

I am building Linux Kernel 2.6.36.4 on a Dell Laptop which has Linux Kernel 2.6.35.11 running. BTW I got the source from kernel.org. The source had few syntax errors which I fixed in the process and ...
1
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1answer
2k views

How to view and change kernel memory size?

How can i view the kernel's share of memory on a machine? How can I increase it? What should I consider before doing it?
28
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1answer
2k views

Why isn't a straightforward 1/5/15 minute moving average used in Linux load calculation?

Until recently i thought the load average (as shown for example in top) was a moving average on the n last values of the number of process in state "runnable" or "running". And n would have been ...
1
vote
1answer
501 views

How can I use my server to compile a kernel for my laptop?

My laptop, an HP pavilion with an nVidia card, has some issues with suspending. Namely firewire breaks on suspend and the nvidia drivers cause Xorg to hang on resume. I'd like to compile my own kernel ...
2
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2answers
1k views

no network device found after Kernel update

So I managed to install Debian 5 on an eBox 3300MX (an embedded type computer). I added a custom kernel after getting a basic install done. That was to get the network card to work. After that, I ...
9
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1answer
6k views

Unable to handle kernel paging request?

[Disclaimer: I was initially a little nervous about posting this here, so I asked on Meta if discussing homebrew / modding was acceptable. Based on the response I've gotten from several veteran ...
2
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1answer
187 views

Add latency when accessing certain websites under linux

I've been playing with tc on my local machine. sudo tc qdisc add dev eth0 root netem delay 2000ms adds a 2-second latency to all traffic going through eth0. What I want is to be able to limit this ...
14
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4answers
3k views

Read the stack of another process?

I'm trying to read a child process's stack but with no luck. I know it is possible using ptrace, but ptrace's interface allows you to read only one word at a time, and I'm trying to scan a larger ...
1
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0answers
286 views

error booting the custom compiled kernel 2.6.37 on ubuntu 10.04 : gave up waiting on root device [duplicate]

Possible Duplicate: Kernel can't find /dev/sda file during boot Hi, I know this is very common problem and there are many threads discussing it. However after trying many solutions ...
3
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2answers
426 views

How do I profile the kernel?

I'm having issues with a kworker process during system boot and I'd like to get such a nice call graph like Linus Torvalds posted here. How would I do this?
4
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2answers
323 views

“Linux supports the dynamic loading of kernel modules. ”

I read in a book written by Robert Love that: Linux supports the dynamic loading of kernel modules. He said this is the difference between Linux and Unix, but I seem to recall there is also KLD ...
3
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3answers
1k views

Book on Linux kernel driver development [closed]

What good books are there out there for Linux kernel driver development? Preferably targeting a rather new kernel release. Which one is best in you opinion? Essential Linux Device Drivers Linux ...
5
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2answers
417 views

Which kernel does reboot load?

I am using ssh to remotely access some machines. These machines have a custom kernel installed (based on the 2.6.28 source). However, whenever I try to reboot the machines using sudo reboot, the ...
5
votes
1answer
4k views

Hung system call

So I'm working with a custom kernel module that I'm writing a python front end for. The kernel module works, and it adds a framebuffer device file to /dev/fb1. I can read and write to it fine. I've ...
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3answers
3k views

Implications of Linux support for AMD Fusion APUs?

As I understand it, the Linux kernel has had good support for Intel and AMD CPUs (pretty obvious since your OS installs and runs fine!). But now that AMD is releasing their new Fusion APUs, is it ...
4
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3answers
3k views

'fast interrupts' in Linux

as far as I know, Linux has 'fast interrupts', those that were requested with SA_INTERRUPT flag; fast interrupts are executed with all other interrupts disabled on the current CPU. But how does it ...
3
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2answers
3k views

re-entrency of interrupts in Linux

I was reading "Linux device drivers, 3rd edition" and don't completely understand a part describing interrupt handlers. I would like to clarify: are the interrupt handlers in Linux nonpreemptible? ...
4
votes
3answers
733 views

Preloading the OOM Killer

I don't have any swap partition/file on my machine, and only 2GB of RAM. Sometimes it happens that the memory gets saturated by some process (Xorg+browser+compiler+...) and the system hangs ...
25
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1answer
36k views

How is a message queue implemented in the Linux kernel?

I would like to know how Message Queues are implemented in the Linux Kernel.
15
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4answers
552 views

How do I learn what I can do with /proc and /sys

I'd like to know more about the advanced uses of the /proc and /sys virtual filesystems, but I don't know where to begin. Can anyone suggest any good sources to learn from? Also, since I think sys has ...
0
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2answers
348 views

FreeBSD's kernel is 'locked'?

I happened to talk to a Mac Genius on the subject of viruses. He mentioned that the FreeBSD kernel on which the Mac OS is based is 'locked' and therefore no viruses can ever harm my Mac. I didn't ...
2
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2answers
988 views

Questions on Linux kernel internals [closed]

I was reading "Linux device drivers, 3rd edition" and faced a few kernel items I don't quite understand. Hope gurus on this forum will help me out. Does the Linux kernel internally operate with ...
8
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2answers
3k views

How do I debug a kernel module in which a NULL pointer appears?

I have a custom kernel module that I compiled from this patch that adds support for the logitech G19 keyboard among other G series devices. I compiled it just fine against Ubuntu's maverick kernel's ...
4
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1answer
372 views

Changes to input_get_keycode function in linux kernel (input/input.c)

I'm working on building a kernel module for an input device, and I noticed that in the module source, there's a couple calls to input_get_keycode(data->input_dev, scancode, &keycode); When I ...
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vote
2answers
847 views

S3 sleep problems — nVidia or Intel H67 (Sandy Bridge motherboard) issue?

I have a new Sandy Bridge i5-2500 and Intel H67 motherboard. As the onboard video didn't work, I put in an older 8600 gts graphics card. However, the S3 suspend won't work (and I can't test without ...
14
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5answers
12k views

Use of O_DIRECT on Linux

If this question is too programmer oriented, let me know. I wonder if there are people familiar with the O_DIRECT flag for the open() system call on Linux 2.6? Linus disparages its use, however high ...
25
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8answers
10k views

How does Linux kernel compare to microkernel architectures?

I read once that one advantage of a microkernel architecture is that you can stop/start essential services like networking and filesystems, without needing to restart the whole system. But considering ...
92
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4answers
61k views

How do I read from /proc/$pid/mem under Linux?

The Linux proc(5) man page tells me that /proc/$pid/mem “can be used to access the pages of a process's memory”. But a straightforward attempt to use it only gives me $ cat /proc/$$/mem ...
3
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1answer
282 views

Can't shutdown mandriva 2010.2

I can't seem to shutdown my machine from mandriva,I have to restart to shut it down from GRUB it says "System Halted" and just freezes there I'm using the x86_64 GNOME version I've already asked on ...
1
vote
1answer
791 views

Select YeAH-TCP like congestion control algorithm to configure kernel

I'm configuring/compiling the 2.6.37 kernel and I want select YeAH-TCP like default congestion control algorithm but, although I enable this option (CONFIG_TCP_CONG_YEAH), it doesn't show in the ...
5
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1answer
2k views

Usage of inb, inl, inw to access kernel space from user space

What are some user space examples of using inb, inl, and inw to access kernel space in Linux?
5
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1answer
314 views

Why do I need ntfs-3g when I have already enabled NTFS support in the kernel?

When configuring the kernel I see an option to add read-write support for NTFS. Then when mounting my NTFS partition I still have to install ntfs-3g and pass ntfs-3g as the type. I thought if I add ...
25
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4answers
37k views

How is an Interrupt handled in Linux?

I just know that Interrupt is a hardware signal assertion caused in a processor pin. But I would like to know how Linux OS handles it. What all are the things that happen when an interrupt occurs?
4
votes
1answer
924 views

More doubts in bzImage

The description of the bzImage in Wikipedia is really confusing me. The above picture is from Wikipedia, but the line next to it is: The bzImage file is in a specific format: It contains ...
9
votes
2answers
858 views

Install new kernel in PowerPC debian

I compiled a new kernel image on x86 using cross compiler with these commands (source): $ cp arch/powerpc/configs/pmac32_defconfig .config $ make ARCH=powerpc menuconfig $ make ARCH=powerpc ...
18
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2answers
6k views

Why does high disk I/O reduce system responsiveness/performance?

I never quite understood why high disk I/O slowed the system so much. It's strange to me because I would expect the slow-down to affect only those processes dependent on the hard/optical drive data, ...
5
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2answers
413 views

How to debug an inserted kernel module?

I would like to debug a loaded kernel module I don't have the source code to; I suspect it's a virus. Is there a way to feed it into GDB for analysis?
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3answers
2k views

Who wrote the “Linux kernel” (Linus Torvalds and his team)?

Who are the authors of the pure Linux kernel from scratch, which was integrated with GNU tools and formed the full GNU/Linux Operating system in the 1990s? I have read some wiki articles but I haven't ...
1
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1answer
542 views

System.map file update

I found that System.map file contains addresses of symbols. Does it involve system calls? I read that it is only updated when a new kernel is newly compiled. So does that means that except for a new ...