linux/kernel/bpf
Jose Fernandez ce09cbdd98 bpf: Improve program stats run-time calculation
This patch improves the run-time calculation for program stats by
capturing the duration as soon as possible after the program returns.

Previously, the duration included u64_stats_t operations. While the
instrumentation overhead is part of the total time spent when stats are
enabled, distinguishing between the program's native execution time and
the time spent due to instrumentation is crucial for accurate
performance analysis.

By making this change, the patch facilitates more precise optimization
of BPF programs, enabling users to understand their performance in
environments without stats enabled.

I used a virtualized environment to measure the run-time over one minute
for a basic raw_tracepoint/sys_enter program, which just increments a
local counter. Although the virtualization introduced some performance
degradation that could affect the results, I observed approximately a
16% decrease in average run-time reported by stats with this change
(310 -> 260 nsec).

Signed-off-by: Jose Fernandez <josef@netflix.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240402034010.25060-1-josef@netflix.com
2024-04-02 16:51:15 +02:00
..
preload
arena.c bpf,arena: Use helper sizeof_field in struct accessors 2024-03-28 18:31:36 -07:00
arraymap.c bpf: Consistently use BPF token throughout BPF verifier logic 2024-01-24 16:21:01 -08:00
bloom_filter.c bpf: Check bloom filter map value size 2024-03-27 09:56:17 -07:00
bpf_cgrp_storage.c bpf: Enable bpf_cgrp_storage for cgroup1 non-attach case 2023-12-08 17:08:18 -08:00
bpf_inode_storage.c
bpf_iter.c bpf: move sleepable flag from bpf_prog_aux to bpf_prog 2024-03-11 16:41:25 -07:00
bpf_local_storage.c bpf: Allow compiler to inline most of bpf_local_storage_lookup() 2024-02-11 14:06:24 -08:00
bpf_lru_list.c
bpf_lru_list.h bpf: lru: Remove unused declaration bpf_lru_promote() 2023-08-08 17:21:42 -07:00
bpf_lsm.c bpf: Minor clean-up to sleepable_lsm_hooks BTF set 2024-02-01 18:37:45 +01:00
bpf_struct_ops.c bpf: Check return from set_memory_rox() 2024-03-18 14:18:47 -07:00
bpf_task_storage.c
btf.c bpf: Recognize btf_decl_tag("arg: Arena") as PTR_TO_ARENA. 2024-03-11 15:37:24 -07:00
cgroup.c bpf: Allow helper bpf_get_[ns_]current_pid_tgid() for all prog types 2024-03-19 14:24:07 -07:00
cgroup_iter.c bpf: Let verifier consider {task,cgroup} is trusted in bpf_iter_reg 2023-11-07 15:24:25 -08:00
core.c bpf: Mark bpf prog stack with kmsan_unposion_memory in interpreter mode 2024-03-28 19:00:59 -07:00
cpumap.c bpf: report RCU QS in cpumap kthread 2024-03-20 21:05:43 -07:00
cpumask.c bpf: treewide: Annotate BPF kfuncs in BTF 2024-01-31 20:40:56 -08:00
devmap.c bpf: Fix DEVMAP_HASH overflow check on 32-bit arches 2024-03-07 20:02:38 -08:00
disasm.c bpf: Disasm support for addr_space_cast instruction. 2024-03-11 15:37:24 -07:00
disasm.h
dispatcher.c bpf: Use arch_bpf_trampoline_size 2023-12-06 17:17:20 -08:00
hashtab.c bpf: Mitigate latency spikes associated with freeing non-preallocated htab 2024-03-28 18:31:40 -07:00
helpers.c bpf: add bpf_modify_return_test_tp() kfunc triggering tracepoint 2024-03-28 18:31:40 -07:00
inode.c bpf: Support symbolic BPF FS delegation mount options 2024-01-24 16:21:02 -08:00
Kconfig bpf: Merge two CONFIG_BPF entries 2024-02-07 16:38:20 -08:00
link_iter.c
local_storage.c
log.c bpf: Recognize addr_space_cast instruction in the verifier. 2024-03-11 15:37:24 -07:00
lpm_trie.c bpf: Avoid kfree_rcu() under lock in bpf_lpm_trie. 2024-03-29 11:10:41 -07:00
Makefile bpf: Introduce bpf_arena. 2024-03-11 15:37:23 -07:00
map_in_map.c bpf: Optimize the free of inner map 2023-12-04 17:50:26 -08:00
map_in_map.h bpf: Add map and need_defer parameters to .map_fd_put_ptr() 2023-12-04 17:50:26 -08:00
map_iter.c bpf: treewide: Annotate BPF kfuncs in BTF 2024-01-31 20:40:56 -08:00
memalloc.c bpf: Remove unnecessary cpu == 0 check in memalloc 2024-01-04 10:18:14 -08:00
mmap_unlock_work.h
mprog.c bpf: Handle bpf_mprog_query with NULL entry 2023-10-06 17:11:20 -07:00
net_namespace.c
offload.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-09-21 21:49:45 +02:00
percpu_freelist.c
percpu_freelist.h
prog_iter.c
queue_stack_maps.c bpf: Avoid deadlock when using queue and stack maps from NMI 2023-09-11 19:04:49 -07:00
reuseport_array.c
ringbuf.c bpf: Fold smp_mb__before_atomic() into atomic_set_release() 2023-10-24 14:26:07 +02:00
stackmap.c bpf: Fix stackmap overflow check on 32-bit arches 2024-03-07 20:06:25 -08:00
syscall.c bpf: support BPF cookie in raw tracepoint (raw_tp, tp_btf) programs 2024-03-19 23:05:34 -07:00
sysfs_btf.c
task_iter.c bpf: Fix an issue due to uninitialized bpf_iter_task 2024-02-19 12:28:15 +01:00
tcx.c bpf, tcx: Get rid of tcx_link_const 2023-10-23 15:01:53 -07:00
tnum.c bpf: simplify tnum output if a fully known constant 2023-12-02 11:36:51 -08:00
token.c bpf,token: Use BIT_ULL() to convert the bit mask 2024-01-29 20:04:55 -08:00
trampoline.c bpf: Improve program stats run-time calculation 2024-04-02 16:51:15 +02:00
verifier.c bpf: Add a verbose message if map limit is reached 2024-04-02 16:12:00 +02:00