bpftrace

High-level tracing language for Linux eBPF

iovisor/bpftrace
starsStars 3341
forksForks 455
watchersWatchers 3341
current-versionCurrent version v0.11.4
total-releasesTotal releases 12
open_issues_countOpen issues 258
dateFirst release 2019-01-06
dateLatest release 2020-11-14
updateLast update 2020-12-23

bpftrace

bpftrace is a high-level tracing language for Linux enhanced Berkeley Packet Filter (eBPF) available in recent Linux kernels (4.x). bpftrace uses LLVM as a backend to compile scripts to BPF-bytecode and makes use of Alastair Robertson.

To learn more about bpftrace, see the One-Liner Tutorial.

One-Liners

The following one-liners demonstrate different capabilities:

# Files opened by process
bpftrace -e 'tracepoint:syscalls:sys_enter_open { printf("%s %s\n", comm, str(args->filename)); }'

# Syscall count by program
bpftrace -e 'tracepoint:raw_syscalls:sys_enter { @[comm] = count(); }'

# Read bytes by process:
bpftrace -e 'tracepoint:syscalls:sys_exit_read /args->ret/ { @[comm] = sum(args->ret); }'

# Read size distribution by process:
bpftrace -e 'tracepoint:syscalls:sys_exit_read { @[comm] = hist(args->ret); }'

# Show per-second syscall rates:
bpftrace -e 'tracepoint:raw_syscalls:sys_enter { @ = count(); } interval:s:1 { print(@); clear(@); }'

# Trace disk size by process
bpftrace -e 'tracepoint:block:block_rq_issue { printf("%d %s %d\n", pid, comm, args->bytes); }'

# Count page faults by process
bpftrace -e 'software:faults:1 { @[comm] = count(); }'

# Count LLC cache misses by process name and PID (uses PMCs):
bpftrace -e 'hardware:cache-misses:1000000 { @[comm, pid] = count(); }'

# Profile user-level stacks at 99 Hertz, for PID 189:
bpftrace -e 'profile:hz:99 /pid == 189/ { @[ustack] = count(); }'

# Files opened, for processes in the root cgroup-v2
bpftrace -e 'tracepoint:syscalls:sys_enter_openat /cgroup == cgroupid("/sys/fs/cgroup/unified/mycg")/ { printf("%s\n", str(args->filename)); }'

More powerful scripts can easily be constructed. See Tools for examples.

Install

For build and install instructions, see INSTALL.md.

Tools

bpftrace contains various tools, which also serve as examples of programming in the bpftrace language.

For more eBPF observability tools, see bcc tools.

Probe types

See the Reference Guide for more detail.

Support

For additional help / discussion, please use our discourse.

Contributing

Development

For development and testing a Vagrantfile is available.

Make sure you have the vbguest plugin installed, it is required to correctly install the shared file system driver on the ubuntu boxes:

$ vagrant plugin install vagrant-vbguest

Start VM:

$ vagrant status
$ vagrant up $YOUR_CHOICE
$ vagrant ssh $YOUR_CHOICE

License

Copyright 2019 Alastair Robertson

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.