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Creating a vDSO: the Colonel's Other Chicken

Feb 07, 2012, 19:00 (0 Talkback[s])
(Other stories by Matt Davis)

"A vDSO (virtual dynamic shared object) is an alternative to the somewhat cycle-expensive system call interface that the GNU/Linux kernel provides...

The traditional mechanism of communication between userland applications and the kernel is something called a system call. Syscalls are implemented as software interrupts providing the userland application with some kernel functionality. For instance, gettimeofday() and fork() are both system calls. The reason syscalls exist is due to the fact that the Linux kernel is divided into two primary segments of memory: userland and kernel land.

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