Helper function bpf_ktime_get_coarse_ns

v5.11

Definition

Copyright (c) 2015 The Libbpf Authors. All rights reserved.

Return a coarse-grained version of the time elapsed since system boot, in nanoseconds. Does not include time the system was suspended.

See: clock_gettime(CLOCK_MONOTONIC_COARSE)

Returns

Current ktime.

static __u64 (* const bpf_ktime_get_coarse_ns)(void) = (void *) 160;

Usage

This function returns a coarse-grained 64-bit timestamp in nanoseconds since system boot, excluding suspended time. It is similar to bpf_ktime_get_ns(), but offers lower precision in exchange for better performance. It is suitable for low-overhead time measurements.

Program types

This helper call can be used in the following program types:

• BPF_PROG_TYPE_CGROUP_SOCK
• BPF_PROG_TYPE_CGROUP_SYSCTL
• BPF_PROG_TYPE_FLOW_DISSECTOR
• BPF_PROG_TYPE_SK_LOOKUP
• BPF_PROG_TYPE_SK_MSG
• BPF_PROG_TYPE_SK_REUSEPORT
• BPF_PROG_TYPE_SK_SKB
• BPF_PROG_TYPE_SOCK_OPS

Example

__u64 start_time = bpf_ktime_get_coarse_ns();
/* some tasks */
__u64 end_time = bpf_ktime_get_coarse_ns();
__u64 duration = end_time - start_time;