Все вопросы: [kernel]

178 вопросов

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Typical scheduling time quantum in modern operating systems

What are typical durations of an operating system process/thread scheduling quantum? I realize that this can vary with the scheduling algorithm, priorities, workloads, hardware, etc., so I'm expecting answers to come with conditions/assumptions, or to be ballpark. I can find examples that seem t...

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1ответов
108 просмотров

How do you start off with implementing a thread library?

How to write kernel code in C ? Where can we look forward to learn more of writing kernel code ? I want to know writing programs in C that can be used to modify my kernel. How do i do that ? What resources can i look upto ?

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2ответов
8628 просмотров

Virtual Webcam in C++

I want to write a new virtual webcam driver, which for example will take an AVI or live stream for example for screen and stream it as webcam source. I'll not have webcam really, I want to add a virtual webcam which streams desktop screen. I should write a webcam in kernel mode to do so ? If s...

2
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3ответов
4133 просмотров

How to create a "Block device" in Windows

For those familiar with Linux, it is possible to create a module and register it as a block device. This allows the user to mount it as a regular disk (while all the block I/O is handled by the module, e.g. usb-massstorage). Is there a way to do this in Windows ? (Need to create a volume mountab...

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2ответов
271 просмотров

System Wide I/O Statistics

In earlier versions of "vmstat", the device minor version was used to determine whether it was a partition or a disk (0 => disk and >0 => partition)). Am I not correct? Then, from kernel version 2.6.x some metrics were measured only at the disk-level, and hence the parsing algorithm was ...

6
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6ответов
4002 просмотров

Linux kernel modules - security risk?

How much of a security risk are linux kernel modules? I remember reading that it was possible if someone got access, that all they had to do was load a rootkit module. Is this correct? Is there any way to protect against this? What parts of the kernel are actually exposed through the module inte...

2
голосов
2ответов
705 просмотров

Using an IOService port reference to turn off a device

This question relates to IO Kit programming on Mac OS X. I have an IO Service Port reference (io_service_t). Is there an API I can use to make whatever is on the end of that IOService port reference power off? I have tried with all my googling might, but have not found a solution. Any help wo...

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1ответов
1271 просмотров

Do Kexec and Kdump work under VMware?

Under Linux you can use Kdump to reliably capture the state of the system at the time of an OOPS ( kernel crash ) . Does Kdump work the same when the kernel is running under VMWare? I'm using VmWare Server 2.0.

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1ответов
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Determining size of bit vectors for memory management given hard limit on memory

After searching around a bit and consulting the Dinosaur Book, I've come to SO seeking wisdom. Note that this is somewhat homework-related, but actually isn't a homework problem. Also, this is using the C programming language. I'm working with a kernel that currently allocates memory in 4K chunk...

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1ответов
1301 просмотров

Accessing the proc_dir_entry from proc_fops.open?

I writing a linux kernel module that does some work with /proc... I'm trying to use the new seq methods for returning the data for /proc... Anyhow, after I call proc_create_data() I have a proc_dir_entry (whose ->data member is pointing at my supplied context)... Anyhow, the file_operations st...

2
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1ответов
538 просмотров

Multi thread .NET application causes Application Error in KERNEL32.dll running on 64 bit quad core Windows Server

I have a multi-threaded .NET application that occasionally terminates without any message. When I check the log there is an entry for an "Application Error in KERNEL32.dll". What could be causing this? Here is some basic code: foreach (int id in ids) { ThreadPool.QueueUserWorkItem(new WaitCal...

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8ответов
133348 просмотров

Linux Process States

In Linux, what happens to the state of a process when it needs to read blocks from a disk? Is it blocked? If so, how is another process chosen to execute?

1
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1ответов
318 просмотров

Where do you store user context in Linux character drivers?

It's been a while since I worked on a Linux kernel module, and I seem to remember that there was a place to stash context in your open() open implementation that would be available in your other file_operations... For example, if I want to maintain some state associated with everyone that opens m...

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2ответов
6860 просмотров

get _complete_ process name from pid

I am in a kernel module and I want to have the whole process name from a given pid. exactly: I want the line which is hold in /proc/PID/cmdline. The problem is that task_struct->comm[] is only 15 bytes long and doesn't handle if a program changes his argv[] manually or via setproctitle(3)... ...

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3ответов
3573 просмотров

Best way to watch process (and sub-processes) for file system read() I/O?

I would like to develop a command line program that worked like so: myprogram /c [some_executable_here] Which launched the command specified by the user and "watched" the process (and any sub-processes) for read I/O and when that program exits, print a listing of files that were "read" (ultimat...

6
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3ответов
7892 просмотров

Direct access to linux framebuffer - copyarea

I want to move very quickly a rectangle over a framebuffer in an embedded linux application. I have found that the function cfb_copyarea may be useful. But I cannot find any ioctl over the /dev/fb device to call the function. Or can this function be called directly?

4
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1ответов
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Mac X Framework Kernel not found

I am trying to link to the Kernel framework as a 3rd party library is using functions from the I/O Kit library (http://developer.apple.com/mac/library/documentation/Darwin/Reference/KernelIOKitFramework/index.html). I am new to development on MacX, I am on Snow Leopard and I compile with the -m3...

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How do I configure the Linux kernel within Buildroot?

I'm trying to build a rootfs for an x86 target, which is all simple enough. However I can't figure out how I configure the kernel that buildroot produces. The first run through came up with menuconfig, but it's cached the .config since then and I can't see where to change it. ~650MB of kernel ...

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2ответов
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Windows processes in kernel vs system

I have a few questions related to Windows processes in kernel and usermode. If I have a hello world application, and a hello world driver that exposes a new system call, foo(), I am curious about what I can and can't do once I am in kernel mode. For starters, when I write my new hello world app...

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1061 просмотров

What's the cost (in cycles) to switch between Windows Kernel and User mode?

I'm curious what the cost is on modern CPUs in terms of cycles to perform a switch from Kernel and User mode?

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What does the Linux /proc/meminfo "Mapped" topic mean?

What does the Linux /proc/meminfo "Mapped" topic mean? I have seen several one-liners that tell me it is the "Total size of memory in kilobytes that is mapped by devices or libraries with mmap." But I have now spent almost twenty hours searching the 2.6.30.5 kernel source code trying to confirm...

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Mac Pro 64-bit addressing kernel

I am wondering about an app I am developing and 64-bit addressing. I would like to use around 12 GB of 32 GB available on a Mac Pro. Here's the thing, the kernel is not 64-bit in Snow Leopard on my Mac Pro (efi 32-bit). I am wondering though if I will be able to address that much ram,>4GB p...

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3ответов
4389 просмотров

How to get started with Drivers Programming under windows

I want to start learning drivers programming under windows . I never programed drivers , and i am looking for information how to get started . Any tutorials ,links ,book recommendations , and what development tool kit i should start with ? (WDF will be good one ?) I really want to program foll...

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2ответов
1104 просмотров

How to create your own linux distro?

Is there any resource or book for creating own linux distro.Only good resource i found is this And also what specialities need to start project like this?

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Accessing Remote Kernel Objects In Windows

Is it possible to access kernel objects on remote computers? I was reading that you could access remote kernel objects by using a symbolic link to \Device\Mup\server\object but I am not sure if that would work. Thanks for the help! I know this is a little odd but I was trying to access a named...

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3ответов
2248 просмотров

ARM linux and cross toolchain issue

I have a problem probably with my arm toolchain but maybe there's something other that I do wrong. I have Chinese made dev board qq2440 using Samsung s3c2440 ARM9 uC. I'm using Ubuntu x86 with native gcc(4.3.3) and cross-compile version arm-unknown-linux-uclibc-gcc (crosstool-NG-1.3.2) 4.3.2 I f...

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2011 просмотров

Calling dll from kernel mode c++ windows

How would I go about calling a dll from kernel mode? I have tried making a custom lib file using multiple techniques but I cannot get anything to work. I have also researched on google but cannot seem to find anything. I was also curious if it was possible to create entries in the import addres t...

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Linux redhat kernel-headers

I'm trying to compile a c programming package (thc-ipv6-0.7) on Linux Redhat 2.6.9-42.ELsmp and it's complaining that it can't find "linux/string.h". From google, I learned that this is part of the "kernel-headers" package. If I do "rpm -qa | grep kernel" It shows that "kernel-devel" is inst...

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2ответов
41495 просмотров

On Linux - set maximum open files to unlimited. Possible?

Is it possible to set the maximum number of open files to some "infinite" value or must it be a number? I had a requirement to set the descriptor limit for a daemon user to be "unlimited" and I'm trying to determine if that's possible or how to do it. I've seen some mailing lists refer to a "max...

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295 просмотров

How does srv.sys decide on raw vs core mode depending on the underlying filesystem?

We are developing a file system for Windows using IFS Kit. We started to investigate a performance problem which caused our file system I/O to be much slower when shared over the network. After looking at it with FileMon and TCPView from Sysinternals we found out that if a NTFS/FAT was shared, th...