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Questions tagged [kernel]

In computing, the kernel is a computer program that manages input/output requests from software, and translates them into data processing instructions for the central processing unit and other electronic components of a computer. The kernel is a fundamental part of a modern computer's operating system. This tag is for general questions regarding code that runs in the context of an operating system kernel.

This tag is for general questions regarding code that runs in the context of an operating system kernel (kernelspace, as opposed to userspace), including writing custom kernels. Questions about specific kernels should use a relevant tag (eg. , , ).

This tag is not about other uses of the word "kernel" - for example, questions about CUDA kernels should use the tag.

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Wikipedia

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What are some resources for getting started in operating system development?

One thing I've always wanted to do is develop my very own operating system (not necessarily fancy like Linux or Windows, but better than a simple boot loader which I've already done). I'm having a hard time finding resources/guides that take you…
Giovanni Galbo
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What is the difference between Trap and Interrupt?

What is the difference between Trap and Interrupt? If the terminology is different for different systems, then what do they mean on x86?
David
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How do I convert dmesg timestamp to custom date format?

I am trying to understand the dmesg timestamp and find it hard to convert that to change it to java date/custom date format. Sample dmesg log: [14614.647880] airo(eth1): link lost (missed beacons) So how do I convert 14614.647880 to a standard…
ukanth
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What is the difference between the kernel space and the user space?

What is the difference between the kernel space and the user space? Do kernel space, kernel threads, kernel processes and kernel stack mean the same thing? Also, why do we need this differentiation?
kc3
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What is an OS kernel ? How does it differ from an operating system?

I am not able to understand the difference between a kernel and an operating system. I do not see any difference between them. Is the kernel an operating system?
Xinus
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cscope or ctags why choose one over the other?

I primarily use vim / gvim as an editor and am looking at using a combination of lxr (the Linux Cross Reference) and either cscope or ctags for exploring the kernel source. However, I haven't ever used either cscope or ctags and would like to hear…
Robert S. Barnes
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What is difference between monolithic and micro kernel?

Could anyone please explain with examples difference between monolithic and micro kernel? Also other classifications of the kernel?
Renjith G
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kernel stack and user space stack

What's the difference between kernel stack and user stack? Why kernel stack is used? If a local variable is declared in an ISR, where it will be stored? Does each process has its own kernel stack? Then how the process coordinates between both these…
jkv
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What is the difference between the operating system and the kernel?

I do not understand the difference between operating system and kernel. Can someone please explain it?
gani
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What is __gxx_personality_v0 for?

This is a second-hand question from an OS development site, but it made me curious since I couldn't find a decent explanation anywhere. When compiling and linking a free-standing C++ program using gcc, sometimes a linker error like this…
Bruce Johnston
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What are vdso and vsyscall?

I did sudo cat /proc/1/maps -vv I am attempting to make sense of the output.I can see a lot of shared libraries being mapped to the memory mapping segment as expected. 7f3c00137000-7f3c00179000 r-xp 00000000 08:01 21233923 …
liv2hak
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Context switches much slower in new linux kernels

We are looking to upgrade the OS on our servers from Ubuntu 10.04 LTS to Ubuntu 12.04 LTS. Unfortunately, it seems that the latency to run a thread that has become runnable has significantly increased from the 2.6 kernel to the 3.2 kernel. In fact…
Michael Goldshteyn
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What does [ N ... M ] mean in C aggregate initializers?

From sys.c line 123: void *sys_call_table[__NR_syscalls] = { [0 ... __NR_syscalls-1] = sys_ni_syscall, #include }; sys_call_table is a generic pointer to arrays, I can see that. However what is the notation: [0 ...…
Amumu
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The difference between initrd and initramfs

As far as I know, initrd acts as a block device, thus requiring a filesystem driver (such as ext2). The kernel must have at least one built-in module for detecting filesystem of initrd. In this article, Introducing initramfs, a new model for initial…
Amumu
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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?
Blair
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