I have this function which works just fine. It gives me current system time the way I need: Now I need to also be able to print timestamps I receive from 3rd party lib in 2-3 variables – sec, usec, nsec (optional). Can I somehow construct timespec from these values and reuse the code I already have? Answer You don’t
Tag: time
How to correctly time speed of writing to a disk (i.e. file) in C
I have a Zynq SoC which runs a Linux system and would like to time the speed at which I can write to its SD card in C. I have tried out clock() and clock_gettime() where for the latter, I have done the following: The times that I’m getting are around 0.019 seconds for 2097152 bytes which I believe is
Adding data based on date from another dataframe
I have two datasets. One with multiple dates: and one with sunrise and sunsets data: I want to add a column to the first dataframe with either “Day” or “night”, based on whether the date and time from the first dataframe is between the sunrise and sunset time and dates. I tried copying and if_else functions, but the length of
C++ Linux fastest way to measure time (faster than std::chrono) ? Benchmark included
I’m trying to profile a program where certain critical parts have execution time measured in < 50 nanoseconds. I found that my timer class using std::chrono is too expensive (code with timing takes 40% more time than code without). How can I make a faster timer class? I think some OS-specific system calls would be the fastest solution. The platform
Wall time and cpu time in Linux command time
When I use Linux time command to measure time spent for running a command, which one below corresponds to CPU time and wall time? Answer which one below corresponds to CPU time user is cpu time in user mode, sys is cpu time in kernel mode and wall time? real
Control loop time with usleep
I try to make sure the execution time of each loop to 10ms with usleep , but sometimes it exceeds 10ms. I have no idea how to solve this problem, is it proper to use usleep and gettimeofday in this case? Please help my find out what i missed. Result: 0.0127289 0.0136499 0.0151598 0.0114031 0.014801 Answer To keep the loop
Computation time of processor varies on execution, each time by using gettimeofday() in a C program
I am trying to compare the computation time for performance comparison using different C libraries with gettimeofday() by including time.h and sys/time.h header files. I used gettimeofday() at the start and end of my computation and took the difference. But each time I execute my C code, I get fluctuating time as answer. For example Is there a way I
Measuring execution time – in program code or in shell?
I have a program and I want to measure its execution (wallclock) time for different input sizes. In some other similar questions I read that using clock_gettime in the source code wouldn’t be reliable because of the CPUs branch predictor, register renaming, speculative execution, out-of-order execution etc., and sometimes even the optimizer can move the clock_gettime call someplace other than
uninterrupted execution of Cpp Linux code
Hi is there a method on which I can make my code safe from other OS interrupts etc in Linux GNU? For example if I have the code below and I need to find the exact execution time without other things interrupting my code. I have already looked into pthread_mutex_lock(&cs_mutex); but wasn’t able to stop other operations to run. Answer
Memory used by compiling a code
I use time command to measure the time used to execute a file as: My question: are there any command like time can give the memory used by executing an executable file in linux? Answer You can use /usr/bin/time -v ./filename. It will print a lot of information including memory use. Note: Will use the shell built-in time command.