linux/tools
Andrii Nakryiko fb84b82246 libbpf: add perf buffer API
BPF_MAP_TYPE_PERF_EVENT_ARRAY map is often used to send data from BPF program
to user space for additional processing. libbpf already has very low-level API
to read single CPU perf buffer, bpf_perf_event_read_simple(), but it's hard to
use and requires a lot of code to set everything up. This patch adds
perf_buffer abstraction on top of it, abstracting setting up and polling
per-CPU logic into simple and convenient API, similar to what BCC provides.

perf_buffer__new() sets up per-CPU ring buffers and updates corresponding BPF
map entries. It accepts two user-provided callbacks: one for handling raw
samples and one for get notifications of lost samples due to buffer overflow.

perf_buffer__new_raw() is similar, but provides more control over how
perf events are set up (by accepting user-provided perf_event_attr), how
they are handled (perf_event_header pointer is passed directly to
user-provided callback), and on which CPUs ring buffers are created
(it's possible to provide a list of CPUs and corresponding map keys to
update). This API allows advanced users fuller control.

perf_buffer__poll() is used to fetch ring buffer data across all CPUs,
utilizing epoll instance.

perf_buffer__free() does corresponding clean up and unsets FDs from BPF map.

All APIs are not thread-safe. User should ensure proper locking/coordination if
used in multi-threaded set up.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-07-08 15:35:43 +02:00
..
accounting
arch SPDX update for 5.2-rc6 2019-06-21 09:58:42 -07:00
bpf tools: bpftool: Fix json dump crash on powerpc 2019-07-05 23:50:38 +02:00
build treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
cgroup
crypto
debugging
firewire treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
firmware treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
gpio treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
hv treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 280 2019-06-05 17:36:36 +02:00
iio treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
include tools: bpftool: add "prog run" subcommand to test-run programs 2019-07-05 23:48:07 +02:00
io_uring tools/io_uring: sync with liburing 2019-05-23 10:25:26 -06:00
kvm/kvm_stat treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499 2019-06-19 17:09:53 +02:00
laptop treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 505 2019-06-19 17:11:22 +02:00
leds
lib libbpf: add perf buffer API 2019-07-08 15:35:43 +02:00
memory-model tools/memory-model: Add support for synchronize_srcu_expedited() 2019-04-04 13:48:34 -07:00
nfsd
objtool treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
pci treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 341 2019-06-05 17:37:07 +02:00
pcmcia treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 247 2019-06-19 17:09:08 +02:00
perf treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
power treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
scripts
spi treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 178 2019-05-30 11:29:19 -07:00
testing selftests/bpf: add test_tcp_rtt to .gitignore 2019-07-06 00:18:16 +02:00
thermal/tmon treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 89 2019-05-24 17:37:52 +02:00
time treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282 2019-06-05 17:36:37 +02:00
usb treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
virtio treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 482 2019-06-19 17:09:52 +02:00
vm treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282 2019-06-05 17:36:37 +02:00
wmi treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
Makefile