diff options
| author |   Dmitrii Banshchikov <me@ubique.spb.ru> | 2020-11-17 18:45:49 +0000 |
|---|---|---|
| committer |   Daniel Borkmann <daniel@iogearbox.net> | 2020-11-18 23:25:32 +0100 |
| commit | d055126180564a57fe533728a4e93d0cb53d49b3 (patch) | |
| tree | bc4413bce59ff96530fb58525010f22cbb1ff5b3 /kernel/trace | |
| parent | bpf: Add tests for bpf_bprm_opts_set helper (diff) | |
| download | linux-dev-d055126180564a57fe533728a4e93d0cb53d49b3.tar.xz linux-dev-d055126180564a57fe533728a4e93d0cb53d49b3.zip | |
bpf: Add bpf_ktime_get_coarse_ns helper
The helper uses CLOCK_MONOTONIC_COARSE source of time that is less
accurate but more performant.
We have a BPF CGROUP_SKB firewall that supports event logging through
bpf_perf_event_output(). Each event has a timestamp and currently we use
bpf_ktime_get_ns() for it. Use of bpf_ktime_get_coarse_ns() saves ~15-20
ns in time required for event logging.
bpf_ktime_get_ns():
EgressLogByRemoteEndpoint 113.82ns 8.79M
bpf_ktime_get_coarse_ns():
EgressLogByRemoteEndpoint 95.40ns 10.48M
Signed-off-by: Dmitrii Banshchikov <me@ubique.spb.ru>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201117184549.257280-1-me@ubique.spb.ru
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/bpf_trace.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 02986c7b90eb..d255bc9b2bfa 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1280,6 +1280,8 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_ktime_get_ns_proto; case BPF_FUNC_ktime_get_boot_ns: return &bpf_ktime_get_boot_ns_proto; + case BPF_FUNC_ktime_get_coarse_ns: + return &bpf_ktime_get_coarse_ns_proto; case BPF_FUNC_tail_call: return &bpf_tail_call_proto; case BPF_FUNC_get_current_pid_tgid: |