clock_getres¶

Intro¶

clock_getres - This system call knows the resolution (precision) of the specified clock, i.e. the period between successive readings.

Description¶

The clock_getres system call gets current clock resolution for the specified clock. It returns the resolution of the clock, that is, how often clock periods occur. It is expressed in seconds and nanoseconds. It is allowed for the target of the res argument to be NULL. In this case, the resolution is not returned though the system call does succeed.

One advantage of using this system call instead of other system calls to measure time is that it provides an accurate enough resolution to measure even small chunks of time. As such, it is widely used in benchmarking and performance testing applications. A potential drawback of using this system call to measure time is that the resolution of the clock is based on the system, so the accuracy of the measurement may vary across different system configurations.

Arguments¶

clockid:const clockid_t - The clock ID to get the resolution of.
res:struct timespec*[K] - Pointer to a timespec structure filled by the kernel with the resolution of the clock.

Available Tags¶

K - Originated from kernel-space.

Hooks¶

sys_clock_getres¶

Type¶

Kprobe + Kretprobe

Purpose¶

Hooking the sys_clock_getres function allows us to properly measure the time of execution of the clock_getres system call.

Example Use Case¶

The clock_getres system call can be used in performance tests or benchmarking applications in order to accurately measure the time spent in certain parts of the code.

Issues¶

No known issues.

clock_gettime

This document was automatically generated by OpenAI and needs review. It might not be accurate and might contain errors. The authors of Tracee recommend that the user reads the "events.go" source file to understand the events and their arguments better.