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Namhyung Kim 177f4eac7f perf ftrace: Add -b/--use-bpf option for latency subcommand
The -b/--use-bpf option is to use BPF to get latency info of kernel
functions.  It'd have better performance impact and I observed that
latency of same function is smaller than before when using BPF.

Committer testing:

  # strace -e bpf perf ftrace latency -b -T __handle_mm_fault -a sleep 1
  bpf(BPF_PROG_LOAD, {prog_type=BPF_PROG_TYPE_SOCKET_FILTER, insn_cnt=2, insns=0x7fff51914e00, license="GPL", log_level=0, log_size=0, log_buf=NULL, kern_version=KERNEL_VERSION(0, 0, 0), prog_flags=0, prog_name="", prog_ifindex=0, expected_attach_type=BPF_CGROUP_INET_INGRESS, prog_btf_fd=0, func_info_rec_size=0, func_info=NULL, func_info_cnt=0, line_info_rec_size=0, line_info=NULL, line_info_cnt=0, attach_btf_id=0, attach_prog_fd=0}, 128) = 3
  bpf(BPF_BTF_LOAD, {btf="\237\353\1\0\30\0\0\0\0\0\0\0\20\0\0\0\20\0\0\0\5\0\0\0\1\0\0\0\0\0\0\1"..., btf_log_buf=NULL, btf_size=45, btf_log_size=0, btf_log_level=0}, 128) = 3
  bpf(BPF_BTF_LOAD, {btf="\237\353\1\0\30\0\0\0\0\0\0\0000\0\0\0000\0\0\0\t\0\0\0\1\0\0\0\0\0\0\1"..., btf_log_buf=NULL, btf_size=81, btf_log_size=0, btf_log_level=0}, 128) = 3
  bpf(BPF_BTF_LOAD, {btf="\237\353\1\0\30\0\0\0\0\0\0\08\0\0\08\0\0\0\t\0\0\0\0\0\0\0\0\0\0\1"..., btf_log_buf=NULL, btf_size=89, btf_log_size=0, btf_log_level=0}, 128) = 3
  bpf(BPF_BTF_LOAD, {btf="\237\353\1\0\30\0\0\0\0\0\0\0\f\0\0\0\f\0\0\0\7\0\0\0\1\0\0\0\0\0\0\20"..., btf_log_buf=NULL, btf_size=43, btf_log_size=0, btf_log_level=0}, 128) = 3
  bpf(BPF_BTF_LOAD, {btf="\237\353\1\0\30\0\0\0\0\0\0\0000\0\0\0000\0\0\0\t\0\0\0\1\0\0\0\0\0\0\1"..., btf_log_buf=NULL, btf_size=81, btf_log_size=0, btf_log_level=0}, 128) = 3
  bpf(BPF_BTF_LOAD, {btf="\237\353\1\0\30\0\0\0\0\0\0\0000\0\0\0000\0\0\0\5\0\0\0\0\0\0\0\0\0\0\1"..., btf_log_buf=NULL, btf_size=77, btf_log_size=0, btf_log_level=0}, 128) = -1 EINVAL (Invalid argument)
  bpf(BPF_BTF_LOAD, {btf="\237\353\1\0\30\0\0\0\0\0\0\0\350\2\0\0\350\2\0\0\353\2\0\0\0\0\0\0\0\0\0\2"..., btf_log_buf=NULL, btf_size=1515, btf_log_size=0, btf_log_level=0}, 128) = 3
  bpf(BPF_MAP_CREATE, {map_type=BPF_MAP_TYPE_ARRAY, key_size=4, value_size=32, max_entries=1, map_flags=0, inner_map_fd=0, map_name="", map_ifindex=0, btf_fd=0, btf_key_type_id=0, btf_value_type_id=0, btf_vmlinux_value_type_id=0}, 128) = 4
  bpf(BPF_PROG_LOAD, {prog_type=BPF_PROG_TYPE_SOCKET_FILTER, insn_cnt=5, insns=0x7fff51914c30, license="GPL", log_level=0, log_size=0, log_buf=NULL, kern_version=KERNEL_VERSION(0, 0, 0), prog_flags=0, prog_name="", prog_ifindex=0, expected_attach_type=BPF_CGROUP_INET_INGRESS, prog_btf_fd=0, func_info_rec_size=0, func_info=NULL, func_info_cnt=0, line_info_rec_size=0, line_info=NULL, line_info_cnt=0, attach_btf_id=0, attach_prog_fd=0}, 128) = 5
  bpf(BPF_MAP_CREATE, {map_type=BPF_MAP_TYPE_ARRAY, key_size=4, value_size=4, max_entries=1, map_flags=BPF_F_MMAPABLE, inner_map_fd=0, map_name="", map_ifindex=0, btf_fd=0, btf_key_type_id=0, btf_value_type_id=0, btf_vmlinux_value_type_id=0}, 128) = 4
  bpf(BPF_PROG_LOAD, {prog_type=BPF_PROG_TYPE_SOCKET_FILTER, insn_cnt=2, insns=0x7fff51914a80, license="GPL", log_level=0, log_size=0, log_buf=NULL, kern_version=KERNEL_VERSION(0, 0, 0), prog_flags=0, prog_name="test", prog_ifindex=0, expected_attach_type=BPF_CGROUP_INET_INGRESS, prog_btf_fd=0, func_info_rec_size=0, func_info=NULL, func_info_cnt=0, line_info_rec_size=0, line_info=NULL, line_info_cnt=0, attach_btf_id=0, attach_prog_fd=0}, 128) = 4
  bpf(BPF_MAP_CREATE, {map_type=BPF_MAP_TYPE_HASH, key_size=8, value_size=8, max_entries=10000, map_flags=0, inner_map_fd=0, map_name="functime", map_ifindex=0, btf_fd=3, btf_key_type_id=0, btf_value_type_id=0, btf_vmlinux_value_type_id=0}, 128) = 4
  bpf(BPF_MAP_CREATE, {map_type=BPF_MAP_TYPE_HASH, key_size=4, value_size=1, max_entries=1, map_flags=0, inner_map_fd=0, map_name="cpu_filter", map_ifindex=0, btf_fd=3, btf_key_type_id=0, btf_value_type_id=0, btf_vmlinux_value_type_id=0}, 128) = 5
  bpf(BPF_MAP_CREATE, {map_type=BPF_MAP_TYPE_HASH, key_size=4, value_size=1, max_entries=1, map_flags=0, inner_map_fd=0, map_name="task_filter", map_ifindex=0, btf_fd=3, btf_key_type_id=0, btf_value_type_id=0, btf_vmlinux_value_type_id=0}, 128) = 7
  bpf(BPF_MAP_CREATE, {map_type=BPF_MAP_TYPE_PERCPU_ARRAY, key_size=4, value_size=8, max_entries=22, map_flags=0, inner_map_fd=0, map_name="latency", map_ifindex=0, btf_fd=3, btf_key_type_id=0, btf_value_type_id=0, btf_vmlinux_value_type_id=0}, 128) = 8
  bpf(BPF_MAP_CREATE, {map_type=BPF_MAP_TYPE_ARRAY, key_size=4, value_size=4, max_entries=1, map_flags=BPF_F_MMAPABLE, inner_map_fd=0, map_name="func_lat.bss", map_ifindex=0, btf_fd=3, btf_key_type_id=0, btf_value_type_id=30, btf_vmlinux_value_type_id=0}, 128) = 9
  bpf(BPF_MAP_UPDATE_ELEM, {map_fd=9, key=0x7fff51914c40, value=0x7f6e99be2000, flags=BPF_ANY}, 128) = 0
  bpf(BPF_PROG_LOAD, {prog_type=BPF_PROG_TYPE_KPROBE, insn_cnt=18, insns=0x11e4160, license="", log_level=0, log_size=0, log_buf=NULL, kern_version=KERNEL_VERSION(5, 14, 16), prog_flags=0, prog_name="func_begin", prog_ifindex=0, expected_attach_type=BPF_CGROUP_INET_INGRESS, prog_btf_fd=3, func_info_rec_size=8, func_info=0x11dfc50, func_info_cnt=1, line_info_rec_size=16, line_info=0x11e04c0, line_info_cnt=9, attach_btf_id=0, attach_prog_fd=0}, 128) = 10
  bpf(BPF_PROG_LOAD, {prog_type=BPF_PROG_TYPE_KPROBE, insn_cnt=99, insns=0x11ded70, license="", log_level=0, log_size=0, log_buf=NULL, kern_version=KERNEL_VERSION(5, 14, 16), prog_flags=0, prog_name="func_end", prog_ifindex=0, expected_attach_type=BPF_CGROUP_INET_INGRESS, prog_btf_fd=3, func_info_rec_size=8, func_info=0x11dfc70, func_info_cnt=1, line_info_rec_size=16, line_info=0x11f6e10, line_info_cnt=20, attach_btf_id=0, attach_prog_fd=0}, 128) = 11
  bpf(BPF_PROG_LOAD, {prog_type=BPF_PROG_TYPE_TRACEPOINT, insn_cnt=2, insns=0x7fff51914a80, license="GPL", log_level=0, log_size=0, log_buf=NULL, kern_version=KERNEL_VERSION(0, 0, 0), prog_flags=0, prog_name="", prog_ifindex=0, expected_attach_type=BPF_CGROUP_INET_INGRESS, prog_btf_fd=0, func_info_rec_size=0, func_info=NULL, func_info_cnt=0, line_info_rec_size=0, line_info=NULL, line_info_cnt=0, attach_btf_id=0, attach_prog_fd=0}, 128) = 13
  bpf(BPF_LINK_CREATE, {link_create={prog_fd=13, target_fd=-1, attach_type=0x29 /* BPF_??? */, flags=0}}, 128) = -1 EINVAL (Invalid argument)
  --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=1699992, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  bpf(BPF_MAP_LOOKUP_ELEM, {map_fd=8, key=0x7fff51914f84, value=0x11f6fa0, flags=BPF_ANY}, 128) = 0
  #   DURATION     |      COUNT | GRAPH                                          |
       0 - 1    us |         52 | ###################                            |
       1 - 2    us |         36 | #############                                  |
       2 - 4    us |         24 | #########                                      |
       4 - 8    us |          7 | ##                                             |
       8 - 16   us |          1 |                                                |
      16 - 32   us |          0 |                                                |
      32 - 64   us |          0 |                                                |
      64 - 128  us |          0 |                                                |
     128 - 256  us |          0 |                                                |
     256 - 512  us |          0 |                                                |
     512 - 1024 us |          0 |                                                |
       1 - 2    ms |          0 |                                                |
       2 - 4    ms |          0 |                                                |
       4 - 8    ms |          0 |                                                |
       8 - 16   ms |          0 |                                                |
      16 - 32   ms |          0 |                                                |
      32 - 64   ms |          0 |                                                |
      64 - 128  ms |          0 |                                                |
     128 - 256  ms |          0 |                                                |
     256 - 512  ms |          0 |                                                |
     512 - 1024 ms |          0 |                                                |
       1 - ...   s |          0 |                                                |
  +++ exited with 0 +++
  #

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: Changbin Du <changbin.du@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20211215185154.360314-5-namhyung@kernel.org
[ Add missing util/cpumap.h include and removed unused 'fd' variable ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-12-16 12:18:12 -03:00
arch s390 updates for 5.16-rc6 2021-12-15 10:52:01 -08:00
block block-5.16-2021-12-10 2021-12-11 09:25:07 -08:00
certs certs: Add support for using elliptic curve keys for signing modules 2021-08-23 19:55:42 +03:00
crypto Update to zstd-1.4.10 2021-11-13 15:32:30 -08:00
Documentation Char/misc driver fixes for 5.16-rc5 2021-12-12 10:16:34 -08:00
drivers hyperv-fixes for 5.16-rc6 2021-12-15 10:46:03 -08:00
fs An SGID directory handling fix (marked for stable), a metrics 2021-12-15 11:06:41 -08:00
include Char/misc driver fixes for 5.16-rc5 2021-12-12 10:16:34 -08:00
init kbuild: Fix -Wimplicit-fallthrough=5 error for GCC 5.x and 6.x 2021-11-14 18:59:49 -08:00
ipc shm: extend forced shm destroy to support objects from several IPC nses 2021-11-20 10:35:54 -08:00
kernel Merge branch 'akpm' (patches from Andrew) 2021-12-11 08:46:52 -08:00
lib Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2021-12-08 16:06:44 -08:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
mm Merge branch 'for-5.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu 2021-12-11 16:14:17 -08:00
net virtio,vdpa: bugfixes 2021-12-13 14:34:22 -08:00
samples ftrace/samples: Add module to test multi direct modify interface 2021-12-09 13:02:44 -05:00
scripts recordmcount.pl: look for jgnop instruction as well as bcrl on s390 2021-12-12 18:52:26 +01:00
security selinux: fix NULL-pointer dereference when hashtab allocation fails 2021-11-19 16:11:39 -05:00
sound sound fixes for 5.16-rc5 2021-12-10 11:43:00 -08:00
tools perf ftrace: Add -b/--use-bpf option for latency subcommand 2021-12-16 12:18:12 -03:00
usr initramfs: Check timestamp to prevent broken cpio archive 2021-10-24 13:48:40 +09:00
virt KVM: downgrade two BUG_ONs to WARN_ON_ONCE 2021-11-26 06:43:28 -05:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: update email address for Guo Ren 2021-12-10 17:10:55 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Char/misc driver fixes for 5.16-rc5 2021-12-12 10:16:34 -08:00
Makefile Linux 5.16-rc5 2021-12-12 14:53:01 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.