Post as a guest Name. Comparing Linux and Minix While gettimeofday should be one of the simplest system calls in the universe and uname should be another How to get current hour time of day in linux kernel space Ask Question. JimD Log in to post comments. Stay ahead with the world’s most comprehensive technology and business learning platform. Visit the following links:
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Back when Linux was new, wasting 1MB to double in-kernel performance would’ve been ridicolous. By joining our community you will have the ability to post topics, receive our newsletter, use the advanced search, subscribe to threads and access many other special features. Can you suggest me some function to measure the start time and end time so that I can find the difference between both. Want to know which application is best for the job?
Because clock can’t give accracy in msec. I am using linux kernel 2. My question is therefore: Gettimfofday Aug 23, Of course it’s possible that the effect would be less dramatic on x86 hardware running Linux but it’s still an option to consider.
I’m pretty sure that you aren’t supposed to use floating point calculations in kernel code, as the kernel doesn’t keep track of the FPU’s state when the kenel is running code.
gettimeofday(2) – Linux manual page
Here is an example program that shows usage: Stay ahead with the world’s most comprehensive technology and business learning platform.
Bharath 61 1 1. Returns the number of elapsed seconds since midnight at the start of January 1, UTC. You are currently viewing LQ as a guest.
Click Here to receive this Complete Guide absolutely free. If you need to reset your password, click here. Linux – Software This forum is for Software issues. Methodology used by pjm Parent article: The code in user space is as below.
gettimeofday() — user-space vs. system call
Please visit this page to clear all LQ-related cookies. How to get current hour time of day in linux kernel space Ask Question. If you assume the large machine has 10 times as many processes, you’ve still only getttimeofday 0.
For kernel space following code will work With thanks in advance. The code on the vsyscall page which normally runs SYSENTER could spot that the syscall being invoked is gettimeofday and copy out the appropriate value from elsewhere in the vsyscall page without ever transitioning to kernel mode.
c – How to get current hour (time of day) in linux kernel space – Stack Overflow
I have no access getimeofday the usual time functions in the standard library because I am in kernel space. This is, of course, a standard memory for speed trade-off.