License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 22:07:57 +08:00
|
|
|
/* SPDX-License-Identifier: GPL-2.0 */
|
2012-04-26 13:15:22 +08:00
|
|
|
#ifndef _PERF_TARGET_H
|
|
|
|
|
#define _PERF_TARGET_H
|
|
|
|
|
|
|
|
|
|
#include <stdbool.h>
|
|
|
|
|
#include <sys/types.h>
|
|
|
|
|
|
2013-11-13 03:46:16 +08:00
|
|
|
struct target {
|
2012-04-26 13:15:22 +08:00
|
|
|
const char *pid;
|
|
|
|
|
const char *tid;
|
|
|
|
|
const char *cpu_list;
|
|
|
|
|
const char *uid_str;
|
perf stat: Enable counting events for BPF programs
Introduce 'perf stat -b' option, which counts events for BPF programs, like:
[root@localhost ~]# ~/perf stat -e ref-cycles,cycles -b 254 -I 1000
1.487903822 115,200 ref-cycles
1.487903822 86,012 cycles
2.489147029 80,560 ref-cycles
2.489147029 73,784 cycles
3.490341825 60,720 ref-cycles
3.490341825 37,797 cycles
4.491540887 37,120 ref-cycles
4.491540887 31,963 cycles
The example above counts 'cycles' and 'ref-cycles' of BPF program of id
254. This is similar to bpftool-prog-profile command, but more
flexible.
'perf stat -b' creates per-cpu perf_event and loads fentry/fexit BPF
programs (monitor-progs) to the target BPF program (target-prog). The
monitor-progs read perf_event before and after the target-prog, and
aggregate the difference in a BPF map. Then the user space reads data
from these maps.
A new 'struct bpf_counter' is introduced to provide a common interface
that uses BPF programs/maps to count perf events.
Committer notes:
Removed all but bpf_counter.h includes from evsel.h, not needed at all.
Also BPF map lookups for PERCPU_ARRAYs need to have as its value receive
buffer passed to the kernel libbpf_num_possible_cpus() entries, not
evsel__nr_cpus(evsel), as the former uses
/sys/devices/system/cpu/possible while the later uses
/sys/devices/system/cpu/online, which may be less than the 'possible'
number making the bpf map lookup overwrite memory and cause hard to
debug memory corruption.
We need to continue using evsel__nr_cpus(evsel) when accessing the
perf_counts array tho, not to overwrite another are of memory :-)
Signed-off-by: Song Liu <songliubraving@fb.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/lkml/20210120163031.GU12699@kernel.org/
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: kernel-team@fb.com
Link: http://lore.kernel.org/lkml/20201229214214.3413833-4-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-12-30 05:42:14 +08:00
|
|
|
const char *bpf_str;
|
2012-04-26 13:15:22 +08:00
|
|
|
uid_t uid;
|
|
|
|
|
bool system_wide;
|
2012-05-16 17:45:49 +08:00
|
|
|
bool uses_mmap;
|
2013-11-15 21:52:29 +08:00
|
|
|
bool default_per_cpu;
|
|
|
|
|
bool per_thread;
|
perf stat: Introduce 'bperf' to share hardware PMCs with BPF
The perf tool uses performance monitoring counters (PMCs) to monitor
system performance. The PMCs are limited hardware resources. For
example, Intel CPUs have 3x fixed PMCs and 4x programmable PMCs per cpu.
Modern data center systems use these PMCs in many different ways: system
level monitoring, (maybe nested) container level monitoring, per process
monitoring, profiling (in sample mode), etc. In some cases, there are
more active perf_events than available hardware PMCs. To allow all
perf_events to have a chance to run, it is necessary to do expensive
time multiplexing of events.
On the other hand, many monitoring tools count the common metrics
(cycles, instructions). It is a waste to have multiple tools create
multiple perf_events of "cycles" and occupy multiple PMCs.
bperf tries to reduce such wastes by allowing multiple perf_events of
"cycles" or "instructions" (at different scopes) to share PMUs. Instead
of having each perf-stat session to read its own perf_events, bperf uses
BPF programs to read the perf_events and aggregate readings to BPF maps.
Then, the perf-stat session(s) reads the values from these BPF maps.
Please refer to the comment before the definition of bperf_ops for the
description of bperf architecture.
bperf is off by default. To enable it, pass --bpf-counters option to
perf-stat. bperf uses a BPF hashmap to share information about BPF
programs and maps used by bperf. This map is pinned to bpffs. The
default path is /sys/fs/bpf/perf_attr_map. The user could change the
path with option --bpf-attr-map.
Committer testing:
# dmesg|grep "Performance Events" -A5
[ 0.225277] Performance Events: Fam17h+ core perfctr, AMD PMU driver.
[ 0.225280] ... version: 0
[ 0.225280] ... bit width: 48
[ 0.225281] ... generic registers: 6
[ 0.225281] ... value mask: 0000ffffffffffff
[ 0.225281] ... max period: 00007fffffffffff
#
# for a in $(seq 6) ; do perf stat -a -e cycles,instructions sleep 100000 & done
[1] 2436231
[2] 2436232
[3] 2436233
[4] 2436234
[5] 2436235
[6] 2436236
# perf stat -a -e cycles,instructions sleep 0.1
Performance counter stats for 'system wide':
310,326,987 cycles (41.87%)
236,143,290 instructions # 0.76 insn per cycle (41.87%)
0.100800885 seconds time elapsed
#
We can see that the counters were enabled for this workload 41.87% of
the time.
Now with --bpf-counters:
# for a in $(seq 32) ; do perf stat --bpf-counters -a -e cycles,instructions sleep 100000 & done
[1] 2436514
[2] 2436515
[3] 2436516
[4] 2436517
[5] 2436518
[6] 2436519
[7] 2436520
[8] 2436521
[9] 2436522
[10] 2436523
[11] 2436524
[12] 2436525
[13] 2436526
[14] 2436527
[15] 2436528
[16] 2436529
[17] 2436530
[18] 2436531
[19] 2436532
[20] 2436533
[21] 2436534
[22] 2436535
[23] 2436536
[24] 2436537
[25] 2436538
[26] 2436539
[27] 2436540
[28] 2436541
[29] 2436542
[30] 2436543
[31] 2436544
[32] 2436545
#
# ls -la /sys/fs/bpf/perf_attr_map
-rw-------. 1 root root 0 Mar 23 14:53 /sys/fs/bpf/perf_attr_map
# bpftool map | grep bperf | wc -l
64
#
# bpftool map | tail
1265: percpu_array name accum_readings flags 0x0
key 4B value 24B max_entries 1 memlock 4096B
1266: hash name filter flags 0x0
key 4B value 4B max_entries 1 memlock 4096B
1267: array name bperf_fo.bss flags 0x400
key 4B value 8B max_entries 1 memlock 4096B
btf_id 996
pids perf(2436545)
1268: percpu_array name accum_readings flags 0x0
key 4B value 24B max_entries 1 memlock 4096B
1269: hash name filter flags 0x0
key 4B value 4B max_entries 1 memlock 4096B
1270: array name bperf_fo.bss flags 0x400
key 4B value 8B max_entries 1 memlock 4096B
btf_id 997
pids perf(2436541)
1285: array name pid_iter.rodata flags 0x480
key 4B value 4B max_entries 1 memlock 4096B
btf_id 1017 frozen
pids bpftool(2437504)
1286: array flags 0x0
key 4B value 32B max_entries 1 memlock 4096B
#
# bpftool map dump id 1268 | tail
value (CPU 21):
8f f3 bc ca 00 00 00 00 80 fd 2a d1 4d 00 00 00
80 fd 2a d1 4d 00 00 00
value (CPU 22):
7e d5 64 4d 00 00 00 00 a4 8a 2e ee 4d 00 00 00
a4 8a 2e ee 4d 00 00 00
value (CPU 23):
a7 78 3e 06 01 00 00 00 b2 34 94 f6 4d 00 00 00
b2 34 94 f6 4d 00 00 00
Found 1 element
# bpftool map dump id 1268 | tail
value (CPU 21):
c6 8b d9 ca 00 00 00 00 20 c6 fc 83 4e 00 00 00
20 c6 fc 83 4e 00 00 00
value (CPU 22):
9c b4 d2 4d 00 00 00 00 3e 0c df 89 4e 00 00 00
3e 0c df 89 4e 00 00 00
value (CPU 23):
18 43 66 06 01 00 00 00 5b 69 ed 83 4e 00 00 00
5b 69 ed 83 4e 00 00 00
Found 1 element
# bpftool map dump id 1268 | tail
value (CPU 21):
f2 6e db ca 00 00 00 00 92 67 4c ba 4e 00 00 00
92 67 4c ba 4e 00 00 00
value (CPU 22):
dc 8e e1 4d 00 00 00 00 d9 32 7a c5 4e 00 00 00
d9 32 7a c5 4e 00 00 00
value (CPU 23):
bd 2b 73 06 01 00 00 00 7c 73 87 bf 4e 00 00 00
7c 73 87 bf 4e 00 00 00
Found 1 element
#
# perf stat --bpf-counters -a -e cycles,instructions sleep 0.1
Performance counter stats for 'system wide':
119,410,122 cycles
152,105,479 instructions # 1.27 insn per cycle
0.101395093 seconds time elapsed
#
See? We had the counters enabled all the time.
Signed-off-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: kernel-team@fb.com
Link: http://lore.kernel.org/lkml/20210316211837.910506-2-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-03-17 05:18:35 +08:00
|
|
|
bool use_bpf;
|
2021-07-23 14:34:32 +08:00
|
|
|
bool hybrid;
|
perf stat: Introduce 'bperf' to share hardware PMCs with BPF
The perf tool uses performance monitoring counters (PMCs) to monitor
system performance. The PMCs are limited hardware resources. For
example, Intel CPUs have 3x fixed PMCs and 4x programmable PMCs per cpu.
Modern data center systems use these PMCs in many different ways: system
level monitoring, (maybe nested) container level monitoring, per process
monitoring, profiling (in sample mode), etc. In some cases, there are
more active perf_events than available hardware PMCs. To allow all
perf_events to have a chance to run, it is necessary to do expensive
time multiplexing of events.
On the other hand, many monitoring tools count the common metrics
(cycles, instructions). It is a waste to have multiple tools create
multiple perf_events of "cycles" and occupy multiple PMCs.
bperf tries to reduce such wastes by allowing multiple perf_events of
"cycles" or "instructions" (at different scopes) to share PMUs. Instead
of having each perf-stat session to read its own perf_events, bperf uses
BPF programs to read the perf_events and aggregate readings to BPF maps.
Then, the perf-stat session(s) reads the values from these BPF maps.
Please refer to the comment before the definition of bperf_ops for the
description of bperf architecture.
bperf is off by default. To enable it, pass --bpf-counters option to
perf-stat. bperf uses a BPF hashmap to share information about BPF
programs and maps used by bperf. This map is pinned to bpffs. The
default path is /sys/fs/bpf/perf_attr_map. The user could change the
path with option --bpf-attr-map.
Committer testing:
# dmesg|grep "Performance Events" -A5
[ 0.225277] Performance Events: Fam17h+ core perfctr, AMD PMU driver.
[ 0.225280] ... version: 0
[ 0.225280] ... bit width: 48
[ 0.225281] ... generic registers: 6
[ 0.225281] ... value mask: 0000ffffffffffff
[ 0.225281] ... max period: 00007fffffffffff
#
# for a in $(seq 6) ; do perf stat -a -e cycles,instructions sleep 100000 & done
[1] 2436231
[2] 2436232
[3] 2436233
[4] 2436234
[5] 2436235
[6] 2436236
# perf stat -a -e cycles,instructions sleep 0.1
Performance counter stats for 'system wide':
310,326,987 cycles (41.87%)
236,143,290 instructions # 0.76 insn per cycle (41.87%)
0.100800885 seconds time elapsed
#
We can see that the counters were enabled for this workload 41.87% of
the time.
Now with --bpf-counters:
# for a in $(seq 32) ; do perf stat --bpf-counters -a -e cycles,instructions sleep 100000 & done
[1] 2436514
[2] 2436515
[3] 2436516
[4] 2436517
[5] 2436518
[6] 2436519
[7] 2436520
[8] 2436521
[9] 2436522
[10] 2436523
[11] 2436524
[12] 2436525
[13] 2436526
[14] 2436527
[15] 2436528
[16] 2436529
[17] 2436530
[18] 2436531
[19] 2436532
[20] 2436533
[21] 2436534
[22] 2436535
[23] 2436536
[24] 2436537
[25] 2436538
[26] 2436539
[27] 2436540
[28] 2436541
[29] 2436542
[30] 2436543
[31] 2436544
[32] 2436545
#
# ls -la /sys/fs/bpf/perf_attr_map
-rw-------. 1 root root 0 Mar 23 14:53 /sys/fs/bpf/perf_attr_map
# bpftool map | grep bperf | wc -l
64
#
# bpftool map | tail
1265: percpu_array name accum_readings flags 0x0
key 4B value 24B max_entries 1 memlock 4096B
1266: hash name filter flags 0x0
key 4B value 4B max_entries 1 memlock 4096B
1267: array name bperf_fo.bss flags 0x400
key 4B value 8B max_entries 1 memlock 4096B
btf_id 996
pids perf(2436545)
1268: percpu_array name accum_readings flags 0x0
key 4B value 24B max_entries 1 memlock 4096B
1269: hash name filter flags 0x0
key 4B value 4B max_entries 1 memlock 4096B
1270: array name bperf_fo.bss flags 0x400
key 4B value 8B max_entries 1 memlock 4096B
btf_id 997
pids perf(2436541)
1285: array name pid_iter.rodata flags 0x480
key 4B value 4B max_entries 1 memlock 4096B
btf_id 1017 frozen
pids bpftool(2437504)
1286: array flags 0x0
key 4B value 32B max_entries 1 memlock 4096B
#
# bpftool map dump id 1268 | tail
value (CPU 21):
8f f3 bc ca 00 00 00 00 80 fd 2a d1 4d 00 00 00
80 fd 2a d1 4d 00 00 00
value (CPU 22):
7e d5 64 4d 00 00 00 00 a4 8a 2e ee 4d 00 00 00
a4 8a 2e ee 4d 00 00 00
value (CPU 23):
a7 78 3e 06 01 00 00 00 b2 34 94 f6 4d 00 00 00
b2 34 94 f6 4d 00 00 00
Found 1 element
# bpftool map dump id 1268 | tail
value (CPU 21):
c6 8b d9 ca 00 00 00 00 20 c6 fc 83 4e 00 00 00
20 c6 fc 83 4e 00 00 00
value (CPU 22):
9c b4 d2 4d 00 00 00 00 3e 0c df 89 4e 00 00 00
3e 0c df 89 4e 00 00 00
value (CPU 23):
18 43 66 06 01 00 00 00 5b 69 ed 83 4e 00 00 00
5b 69 ed 83 4e 00 00 00
Found 1 element
# bpftool map dump id 1268 | tail
value (CPU 21):
f2 6e db ca 00 00 00 00 92 67 4c ba 4e 00 00 00
92 67 4c ba 4e 00 00 00
value (CPU 22):
dc 8e e1 4d 00 00 00 00 d9 32 7a c5 4e 00 00 00
d9 32 7a c5 4e 00 00 00
value (CPU 23):
bd 2b 73 06 01 00 00 00 7c 73 87 bf 4e 00 00 00
7c 73 87 bf 4e 00 00 00
Found 1 element
#
# perf stat --bpf-counters -a -e cycles,instructions sleep 0.1
Performance counter stats for 'system wide':
119,410,122 cycles
152,105,479 instructions # 1.27 insn per cycle
0.101395093 seconds time elapsed
#
See? We had the counters enabled all the time.
Signed-off-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: kernel-team@fb.com
Link: http://lore.kernel.org/lkml/20210316211837.910506-2-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-03-17 05:18:35 +08:00
|
|
|
const char *attr_map;
|
2012-04-26 13:15:22 +08:00
|
|
|
};
|
|
|
|
|
|
2013-11-13 03:46:16 +08:00
|
|
|
enum target_errno {
|
|
|
|
|
TARGET_ERRNO__SUCCESS = 0,
|
2012-05-07 13:09:00 +08:00
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Choose an arbitrary negative big number not to clash with standard
|
|
|
|
|
* errno since SUS requires the errno has distinct positive values.
|
|
|
|
|
* See 'Issue 6' in the link below.
|
|
|
|
|
*
|
|
|
|
|
* http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/errno.h.html
|
|
|
|
|
*/
|
2013-11-13 03:46:16 +08:00
|
|
|
__TARGET_ERRNO__START = -10000,
|
2012-05-07 13:09:00 +08:00
|
|
|
|
2013-11-13 03:46:16 +08:00
|
|
|
/* for target__validate() */
|
|
|
|
|
TARGET_ERRNO__PID_OVERRIDE_CPU = __TARGET_ERRNO__START,
|
|
|
|
|
TARGET_ERRNO__PID_OVERRIDE_UID,
|
|
|
|
|
TARGET_ERRNO__UID_OVERRIDE_CPU,
|
|
|
|
|
TARGET_ERRNO__PID_OVERRIDE_SYSTEM,
|
|
|
|
|
TARGET_ERRNO__UID_OVERRIDE_SYSTEM,
|
2013-11-15 21:52:29 +08:00
|
|
|
TARGET_ERRNO__SYSTEM_OVERRIDE_THREAD,
|
perf stat: Enable counting events for BPF programs
Introduce 'perf stat -b' option, which counts events for BPF programs, like:
[root@localhost ~]# ~/perf stat -e ref-cycles,cycles -b 254 -I 1000
1.487903822 115,200 ref-cycles
1.487903822 86,012 cycles
2.489147029 80,560 ref-cycles
2.489147029 73,784 cycles
3.490341825 60,720 ref-cycles
3.490341825 37,797 cycles
4.491540887 37,120 ref-cycles
4.491540887 31,963 cycles
The example above counts 'cycles' and 'ref-cycles' of BPF program of id
254. This is similar to bpftool-prog-profile command, but more
flexible.
'perf stat -b' creates per-cpu perf_event and loads fentry/fexit BPF
programs (monitor-progs) to the target BPF program (target-prog). The
monitor-progs read perf_event before and after the target-prog, and
aggregate the difference in a BPF map. Then the user space reads data
from these maps.
A new 'struct bpf_counter' is introduced to provide a common interface
that uses BPF programs/maps to count perf events.
Committer notes:
Removed all but bpf_counter.h includes from evsel.h, not needed at all.
Also BPF map lookups for PERCPU_ARRAYs need to have as its value receive
buffer passed to the kernel libbpf_num_possible_cpus() entries, not
evsel__nr_cpus(evsel), as the former uses
/sys/devices/system/cpu/possible while the later uses
/sys/devices/system/cpu/online, which may be less than the 'possible'
number making the bpf map lookup overwrite memory and cause hard to
debug memory corruption.
We need to continue using evsel__nr_cpus(evsel) when accessing the
perf_counts array tho, not to overwrite another are of memory :-)
Signed-off-by: Song Liu <songliubraving@fb.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/lkml/20210120163031.GU12699@kernel.org/
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: kernel-team@fb.com
Link: http://lore.kernel.org/lkml/20201229214214.3413833-4-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-12-30 05:42:14 +08:00
|
|
|
TARGET_ERRNO__BPF_OVERRIDE_CPU,
|
|
|
|
|
TARGET_ERRNO__BPF_OVERRIDE_PID,
|
|
|
|
|
TARGET_ERRNO__BPF_OVERRIDE_UID,
|
|
|
|
|
TARGET_ERRNO__BPF_OVERRIDE_THREAD,
|
2012-05-07 13:09:00 +08:00
|
|
|
|
2013-11-13 03:46:16 +08:00
|
|
|
/* for target__parse_uid() */
|
|
|
|
|
TARGET_ERRNO__INVALID_UID,
|
|
|
|
|
TARGET_ERRNO__USER_NOT_FOUND,
|
2012-05-07 13:09:00 +08:00
|
|
|
|
2013-11-13 03:46:16 +08:00
|
|
|
__TARGET_ERRNO__END,
|
2012-05-07 13:09:00 +08:00
|
|
|
};
|
|
|
|
|
|
2013-11-13 03:46:16 +08:00
|
|
|
enum target_errno target__validate(struct target *target);
|
|
|
|
|
enum target_errno target__parse_uid(struct target *target);
|
2012-04-26 13:15:22 +08:00
|
|
|
|
2013-11-13 03:46:16 +08:00
|
|
|
int target__strerror(struct target *target, int errnum, char *buf, size_t buflen);
|
2012-05-07 13:09:02 +08:00
|
|
|
|
2013-11-13 03:46:16 +08:00
|
|
|
static inline bool target__has_task(struct target *target)
|
2012-05-07 13:09:03 +08:00
|
|
|
{
|
2012-05-16 17:45:47 +08:00
|
|
|
return target->tid || target->pid || target->uid_str;
|
2012-05-07 13:09:03 +08:00
|
|
|
}
|
|
|
|
|
|
2013-11-13 03:46:16 +08:00
|
|
|
static inline bool target__has_cpu(struct target *target)
|
2012-05-07 13:09:03 +08:00
|
|
|
{
|
2012-05-16 17:45:47 +08:00
|
|
|
return target->system_wide || target->cpu_list;
|
2012-05-07 13:09:03 +08:00
|
|
|
}
|
|
|
|
|
|
2013-11-13 03:46:16 +08:00
|
|
|
static inline bool target__none(struct target *target)
|
2012-05-07 13:09:03 +08:00
|
|
|
{
|
2013-11-13 03:46:16 +08:00
|
|
|
return !target__has_task(target) && !target__has_cpu(target);
|
2012-05-07 13:09:03 +08:00
|
|
|
}
|
|
|
|
|
|
2017-12-05 22:03:10 +08:00
|
|
|
static inline bool target__has_per_thread(struct target *target)
|
|
|
|
|
{
|
|
|
|
|
return target->system_wide && target->per_thread;
|
|
|
|
|
}
|
|
|
|
|
|
2013-12-05 06:56:40 +08:00
|
|
|
static inline bool target__uses_dummy_map(struct target *target)
|
|
|
|
|
{
|
|
|
|
|
bool use_dummy = false;
|
|
|
|
|
|
|
|
|
|
if (target->default_per_cpu)
|
|
|
|
|
use_dummy = target->per_thread ? true : false;
|
|
|
|
|
else if (target__has_task(target) ||
|
|
|
|
|
(!target__has_cpu(target) && !target->uses_mmap))
|
|
|
|
|
use_dummy = true;
|
2017-12-05 22:03:10 +08:00
|
|
|
else if (target__has_per_thread(target))
|
|
|
|
|
use_dummy = true;
|
2013-12-05 06:56:40 +08:00
|
|
|
|
|
|
|
|
return use_dummy;
|
|
|
|
|
}
|
|
|
|
|
|
2012-04-26 13:15:22 +08:00
|
|
|
#endif /* _PERF_TARGET_H */
|