linux/kernel/bpf
Alexei Starovoitov 492ecee892 bpf: enable program stats
JITed BPF programs are indistinguishable from kernel functions, but unlike
kernel code BPF code can be changed often.
Typical approach of "perf record" + "perf report" profiling and tuning of
kernel code works just as well for BPF programs, but kernel code doesn't
need to be monitored whereas BPF programs do.
Users load and run large amount of BPF programs.
These BPF stats allow tools monitor the usage of BPF on the server.
The monitoring tools will turn sysctl kernel.bpf_stats_enabled
on and off for few seconds to sample average cost of the programs.
Aggregated data over hours and days will provide an insight into cost of BPF
and alarms can trigger in case given program suddenly gets more expensive.

The cost of two sched_clock() per program invocation adds ~20 nsec.
Fast BPF progs (like selftests/bpf/progs/test_pkt_access.c) will slow down
from ~10 nsec to ~30 nsec.
static_key minimizes the cost of the stats collection.
There is no measurable difference before/after this patch
with kernel.bpf_stats_enabled=0

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-27 17:22:50 +01:00
..
arraymap.c bpf: introduce BPF_F_LOCK flag 2019-02-01 20:55:39 +01:00
bpf_lru_list.c bpf: lru: Lower the PERCPU_NR_SCANS from 16 to 4 2017-04-17 13:55:52 -04:00
bpf_lru_list.h bpf: Only set node->ref = 1 if it has not been set 2017-09-01 09:57:39 -07:00
btf.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-02-08 15:00:17 -08:00
cgroup.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-02-08 15:00:17 -08:00
core.c bpf: enable program stats 2019-02-27 17:22:50 +01:00
cpumap.c bpf/cpumap: make sure frame_size for build_skb is aligned if headroom isn't 2018-12-20 23:19:12 +01:00
devmap.c bpf: devmap: fix wrong interface selection in notifier_call 2018-10-26 00:32:21 +02:00
disasm.c bpf: disassembler support JMP32 2019-01-26 13:33:01 -08:00
disasm.h bpf: Remove struct bpf_verifier_env argument from print_bpf_insn 2018-03-23 17:38:57 +01:00
hashtab.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-02-08 15:00:17 -08:00
helpers.c bpf: introduce BPF_F_LOCK flag 2019-02-01 20:55:39 +01:00
inode.c bpf: decouple btf from seq bpf fs dump and enable more maps 2018-08-13 00:52:45 +02:00
local_storage.c bpf: introduce BPF_F_LOCK flag 2019-02-01 20:55:39 +01:00
lpm_trie.c bpf: pass struct btf pointer to the map_check_btf() callback 2018-12-12 15:33:33 -08:00
Makefile bpf: add queue and stack maps 2018-10-19 13:24:31 -07:00
map_in_map.c bpf: introduce bpf_spin_lock 2019-02-01 20:55:38 +01:00
map_in_map.h bpf: Add syscall lookup support for fd array and htab 2017-06-29 13:13:25 -04:00
offload.c bpf: offload: add priv field for drivers 2019-02-12 17:07:09 +01:00
percpu_freelist.c bpf: fix lockdep false positive in percpu_freelist 2019-01-31 23:18:21 +01:00
percpu_freelist.h bpf: fix lockdep false positive in percpu_freelist 2019-01-31 23:18:21 +01:00
queue_stack_maps.c bpf: fix integer overflow in queue_stack_map 2018-11-22 21:29:40 +01:00
reuseport_array.c bpf: Introduce BPF_MAP_TYPE_REUSEPORT_SOCKARRAY 2018-08-11 01:58:46 +02:00
stackmap.c bpf: zero out build_id for BPF_STACK_BUILD_ID_IP 2019-01-17 16:42:35 +01:00
syscall.c bpf: enable program stats 2019-02-27 17:22:50 +01:00
tnum.c bpf/verifier: improve register value range tracking with ARSH 2018-04-29 08:45:53 -07:00
verifier.c bpf: enable program stats 2019-02-27 17:22:50 +01:00
xskmap.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-10-19 11:03:06 -07:00