perf docs: Fix man page formatting for 'perf lock'

This makes "CONTENTION" a top level section (rather than a subsection of
"INFO").

Fixes: 79079f21f50a501f ("perf lock: Add -k and -F options to 'contention' subcommand")
Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Nick Forrington <nick.forrington@arm.com>
Tested-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20231102161117.49533-1-nick.forrington@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock contention: Add -G/--cgroup-filter option

The -G/--cgroup-filter is to limit lock contention collection on the
tasks in the specific cgroups only.

$ sudo ./perf lock con -abt -G /user.slice/.../vte-spawn-52221fb8-b33f-4a52-b5c3-e35d1e6fc0e0.scope \
./perf bench sched messaging
# Running 'sched/messaging' benchmark:
# 20 sender and receiver processes per group
# 10 groups == 400 processes run

Total time: 0.174 [sec]
contended total wait max wait avg wait pid comm

4 114.45 us 60.06 us 28.61 us 214847 sched-messaging
2 111.40 us 60.84 us 55.70 us 214848 sched-messaging
2 106.09 us 59.42 us 53.04 us 214837 sched-messaging
1 81.70 us 81.70 us 81.70 us 214709 sched-messaging
68 78.44 us 6.83 us 1.15 us 214633 sched-messaging
69 73.71 us 2.69 us 1.07 us 214632 sched-messaging
4 72.62 us 60.83 us 18.15 us 214850 sched-messaging
2 71.75 us 67.60 us 35.88 us 214840 sched-messaging
2 69.29 us 67.53 us 34.65 us 214804 sched-messaging
2 69.00 us 68.23 us 34.50 us 214826 sched-messaging
...

Export cgroup__new() function as it's needed from outside.

Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230906174903.346486-5-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock contention: Add --lock-cgroup option

The --lock-cgroup option shows lock contention stats break down by
cgroups.

Add LOCK_AGGR_CGROUP mode and use it instead of use_cgroup field.

$ sudo ./perf lock con -ab --lock-cgroup sleep 1
contended total wait max wait avg wait cgroup

8 15.70 us 6.34 us 1.96 us /
2 1.48 us 747 ns 738 ns /user.slice/.../app.slice/app-gnome-google\x2dchrome-6442.scope
1 848 ns 848 ns 848 ns /user.slice/.../session.slice/org.gnome.Shell@x11.service
1 220 ns 220 ns 220 ns /user.slice/.../session.slice/pipewire-pulse.service

For now, the cgroup mode only works with BPF (-b).

Committer notes:

Remove -g as it is used in the other tools with a clear meaning of
collect/show callchains. As agreed with Namhyung off list.

Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230906174903.346486-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock contention: Add --output option

To avoid formatting failures for example in CSV output due to debug
messages, add --output option to put the result in a file.
Unfortunately the short -o option was taken by the --owner already.

$ sudo ./perf lock con -ab --output lock-out.txt -v sleep 1
Looking at the vmlinux_path (8 entries long)
symsrc__init: cannot get elf header.
Using /proc/kcore for kernel data
Using /proc/kallsyms for symbols

$ head lock-out.txt
contended total wait max wait avg wait type caller

3 76.79 us 26.89 us 25.60 us rwlock:R ep_poll_callback+0x2d
0xffffffff9a23f4b5 _raw_read_lock_irqsave+0x45
0xffffffff99bbd4dd ep_poll_callback+0x2d
0xffffffff999029f3 __wake_up_common+0x73
0xffffffff99902b82 __wake_up_common_lock+0x82
0xffffffff99fa5b1c sock_def_readable+0x3c
0xffffffff9a11521d unix_stream_sendmsg+0x18d
0xffffffff99f9fc9c sock_sendmsg+0x5c

Suggested-by: Ian Rogers <irogers@google.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230628200141.2739587-4-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

perf lock contention: Add -x option for CSV style output

Sometimes we want to process the output by external programs. Let's add
the -x option to specify the field separator like perf stat.

$ sudo ./perf lock con -ab -x, sleep 1
# output: contended, total wait, max wait, avg wait, type, caller
19, 194232, 21415, 10222, spinlock, process_one_work+0x1f0
15, 162748, 23843, 10849, rwsem:R, do_user_addr_fault+0x40e
4, 86740, 23415, 21685, rwlock:R, ep_poll_callback+0x2d
1, 84281, 84281, 84281, mutex, iwl_mvm_async_handlers_wk+0x135
8, 67608, 27404, 8451, spinlock, __queue_work+0x174
3, 58616, 31125, 19538, rwsem:W, do_mprotect_pkey+0xff
3, 52953, 21172, 17651, rwlock:W, do_epoll_wait+0x248
2, 30324, 19704, 15162, rwsem:R, do_madvise+0x3ad
1, 24619, 24619, 24619, spinlock, rcu_core+0xd4

The first line is a comment that shows the output format. Each line is
separated by the given string ("," in this case). The time is printed
in nsec without the unit so that it can be parsed easily.

The characters can be used in the output like (":", "+" and ".") are not
allowed for the -x option.

$ ./perf lock con -x:
Cannot use the separator that is already used

Usage: perf lock contention [<options>]

-x, --field-separator <separator>
print result in CSV format with custom separator

The stacktraces are printed in the same line separated by ":". The
header is updated to show the stacktrace. Also the debug output is
added at the end as a comment.

$ sudo ./perf lock con -abv -x, -F wait_total sleep 1
Looking at the vmlinux_path (8 entries long)
symsrc__init: cannot get elf header.
Using /proc/kcore for kernel data
Using /proc/kallsyms for symbols
# output: total wait, type, caller, stacktrace
37134, spinlock, rcu_core+0xd4, 0xffffffff9d0401e4 _raw_spin_lock_irqsave+0x44: 0xffffffff9c738114 rcu_core+0xd4: ...
21213, spinlock, raw_spin_rq_lock_nested+0x1b, 0xffffffff9d0407c0 _raw_spin_lock+0x30: 0xffffffff9c6d9cfb raw_spin_rq_lock_nested+0x1b: ...
20506, rwlock:W, ep_done_scan+0x2d, 0xffffffff9c9bc4dd ep_done_scan+0x2d: 0xffffffff9c9bd5f1 do_epoll_wait+0x6d1: ...
18044, rwlock:R, ep_poll_callback+0x2d, 0xffffffff9d040555 _raw_read_lock_irqsave+0x45: 0xffffffff9c9bc81d ep_poll_callback+0x2d: ...
17890, rwlock:W, do_epoll_wait+0x47b, 0xffffffff9c9bd39b do_epoll_wait+0x47b: 0xffffffff9c9be9ef __x64_sys_epoll_wait+0x6d1: ...
12114, spinlock, futex_wait_queue+0x60, 0xffffffff9d0407c0 _raw_spin_lock+0x30: 0xffffffff9d037cae __schedule+0xbe: ...
# debug: total=7, bad=0, bad_task=0, bad_stack=0, bad_time=0, bad_data=0

Also note that some field (like lock symbols) can be empty.

$ sudo ./perf lock con -abl -x, -E 10 sleep 1
# output: contended, total wait, max wait, avg wait, address, symbol, type
6, 275025, 61764, 45837, ffff9dcc9f7d60d0, , spinlock
18, 87716, 11196, 4873, ffff9dc540059000, , spinlock
2, 6472, 5499, 3236, ffff9dcc7f730e00, rq_lock, spinlock
3, 4429, 2341, 1476, ffff9dcc7f7b0e00, rq_lock, spinlock
3, 3974, 1635, 1324, ffff9dcc7f7f0e00, rq_lock, spinlock
4, 3290, 1326, 822, ffff9dc5f4e2cde0, , rwlock
3, 2894, 1023, 964, ffffffff9e0d7700, rcu_state, spinlock
1, 2567, 2567, 2567, ffff9dcc7f6b0e00, rq_lock, spinlock
4, 1259, 596, 314, ffff9dc69c2adde0, , rwlock
1, 934, 934, 934, ffff9dcc7f670e00, rq_lock, spinlock

Acked-by: Ian Rogers <irogers@google.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230628200141.2739587-3-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

perf lock contention: Update default map size to 16384

The BPF hash map will align the map size to a power of 2. So 10k would
be 16k anyway. Let's have the actual size to avoid confusions.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230406210611.1622492-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock contention: Use -M for --map-nr-entries

Users often want to change the map size, let's add a short option (-M)
for that.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230406210611.1622492-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock contention: Add -o/--lock-owner option

When there're many lock contentions in the system, people sometimes want
to know who caused the contention, IOW who's the owner of the locks.

The -o/--lock-owner option tries to follow the lock owners for the
contended mutexes and rwsems from BPF, and then attributes the
contention time to the owner instead of the waiter. It's a best effort
approach to get the owner info at the time of the contention and doesn't
guarantee to have the precise tracking of owners if it's changing over
time.

Currently it only handles mutex and rwsem that have owner field in their
struct and it basically points to a task_struct that owns the lock at
the moment.

Technically its type is atomic_long_t and it comes with some LSB bits
used for other meanings. So it needs to clear them when casting it to a
pointer to task_struct.

Also the atomic_long_t is a typedef of the atomic 32 or 64 bit types
depending on arch which is a wrapper struct for the counter value. I'm
not aware of proper ways to access those kernel atomic types from BPF so
I just read the internal counter value directly. Please let me know if
there's a better way.

When -o/--lock-owner option is used, it goes to the task aggregation
mode like -t/--threads option does. However it cannot get the owner for
other lock types like spinlock and sometimes even for mutex.

$ sudo ./perf lock con -abo -- ./perf bench sched pipe
# Running 'sched/pipe' benchmark:
# Executed 1000000 pipe operations between two processes

Total time: 4.766 [sec]

4.766540 usecs/op
209795 ops/sec
contended total wait max wait avg wait pid owner

403 565.32 us 26.81 us 1.40 us -1 Unknown
4 27.99 us 8.57 us 7.00 us 1583145 sched-pipe
1 8.25 us 8.25 us 8.25 us 1583144 sched-pipe
1 2.03 us 2.03 us 2.03 us 5068 chrome

As you can see, the owner is unknown for the most cases. But if we
filter only for the mutex locks, it'd more likely get the onwers.

$ sudo ./perf lock con -abo -Y mutex -- ./perf bench sched pipe
# Running 'sched/pipe' benchmark:
# Executed 1000000 pipe operations between two processes

Total time: 4.910 [sec]

4.910435 usecs/op
203647 ops/sec
contended total wait max wait avg wait pid owner

2 15.50 us 8.29 us 7.75 us 1582852 sched-pipe
7 7.20 us 2.47 us 1.03 us -1 Unknown
1 6.74 us 6.74 us 6.74 us 1582851 sched-pipe

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hao Luo <haoluo@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230207002403.63590-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock contention: Add -S/--callstack-filter option

The -S/--callstack-filter is to limit display entries having the given
string in the callstack (not only in the caller in the output).

The following example shows lock contention results if the callstack
has 'net' substring somewhere. Note that the caller '__dev_queue_xmit'
does not match to it, but it has 'inet6_csk_xmit' in the callstack.

This applies even if you don't use -v option to show the full callstack.

$ sudo ./perf lock con -abv -S net sleep 1
...
contended total wait max wait avg wait type caller

5 70.20 us 16.13 us 14.04 us spinlock __dev_queue_xmit+0xb6d
0xffffffffa5dd1c60 _raw_spin_lock+0x30
0xffffffffa5b8f6ed __dev_queue_xmit+0xb6d
0xffffffffa5cd8267 ip6_finish_output2+0x2c7
0xffffffffa5cdac14 ip6_finish_output+0x1d4
0xffffffffa5cdb477 ip6_xmit+0x457
0xffffffffa5d1fd17 inet6_csk_xmit+0xd7
0xffffffffa5c5f4aa __tcp_transmit_skb+0x54a
0xffffffffa5c6467d tcp_keepalive_timer+0x2fd

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230126000936.3017683-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock contention: Add -L/--lock-filter option

The -L/--lock-filter option is to filter only given locks. The locks
can be specified by address or name (if exists).

$ sudo ./perf lock record -a sleep 1

$ sudo ./perf lock con -l
contended total wait max wait avg wait address symbol

57 1.11 ms 42.83 us 19.54 us ffff9f4140059000
15 280.88 us 23.51 us 18.73 us ffffffff9d007a40 jiffies_lock
1 20.49 us 20.49 us 20.49 us ffffffff9d0d50c0 rcu_state
1 9.02 us 9.02 us 9.02 us ffff9f41759e9ba0

$ sudo ./perf lock con -L jiffies_lock,rcu_state
contended total wait max wait avg wait type caller

15 280.88 us 23.51 us 18.73 us spinlock tick_sched_do_timer+0x93
1 20.49 us 20.49 us 20.49 us spinlock __softirqentry_text_start+0xeb

$ sudo ./perf lock con -L ffff9f4140059000
contended total wait max wait avg wait type caller

38 779.40 us 42.83 us 20.51 us spinlock worker_thread+0x50
11 216.30 us 39.87 us 19.66 us spinlock queue_work_on+0x39
8 118.13 us 20.51 us 14.77 us spinlock kthread+0xe5

Committer testing:

# uname -a
Linux quaco 6.0.12-200.fc36.x86_64 #1 SMP PREEMPT_DYNAMIC Thu Dec 8 17:15:53 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
# perf lock record
^C[ perf record: Woken up 1 times to write data ]
# perf lock con -L jiffies_lock,rcu_state
contended total wait max wait avg wait type caller

# perf lock con
contended total wait max wait avg wait type caller

1 9.06 us 9.06 us 9.06 us spinlock call_timer_fn+0x24
# perf lock con -L call
ignore unknown symbol: call
contended total wait max wait avg wait type caller

1 9.06 us 9.06 us 9.06 us spinlock call_timer_fn+0x24
#

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Blake Jones <blakejones@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20221219201732.460111-5-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock contention: Add -Y/--type-filter option

The -Y/--type-filter option is to filter the result for specific lock
types only. It can accept comma-separated values. Note that it would
accept type names like one in the output. spinlock, mutex, rwsem:R and
so on.

For RW-variant lock types, it converts the name to the both variants.
In other words, "rwsem" is same as "rwsem:R,rwsem:W". Also note that
"mutex" has two different encoding - one for sleeping wait, another for
optimistic spinning. Add "mutex-spin" entry for the lock_type_table so
that we can add it for "mutex" under the table.

$ sudo ./perf lock record -a -- ./perf bench sched messaging

$ sudo ./perf lock con -E 5 -Y spinlock
contended total wait max wait avg wait type caller

802 1.26 ms 11.73 us 1.58 us spinlock __wake_up_common_lock+0x62
13 787.16 us 105.44 us 60.55 us spinlock remove_wait_queue+0x14
12 612.96 us 78.70 us 51.08 us spinlock prepare_to_wait+0x27
114 340.68 us 12.61 us 2.99 us spinlock try_to_wake_up+0x1f5
83 226.38 us 9.15 us 2.73 us spinlock folio_lruvec_lock_irqsave+0x5e

Committer notes:

Make get_type_flag() return UINT_MAX for error instad of -1UL, as that
function returns 'unsigned int' and we store the value on a 'unsigned
int' 'flags' variable which makes clang unhappy:

35 98.23 fedora:37 : FAIL clang version 15.0.6 (Fedora 15.0.6-1.fc37)
builtin-lock.c:2012:14: error: result of comparison of constant 18446744073709551615 with expression of type 'unsigned int' is always true [-Werror,-Wtautological-constant-out-of-range-compare]
if (flags != -1UL) {
~~~~~ ^ ~~~~
builtin-lock.c:2021:14: error: result of comparison of constant 18446744073709551615 with expression of type 'unsigned int' is always true [-Werror,-Wtautological-constant-out-of-range-compare]
if (flags != -1UL) {
~~~~~ ^ ~~~~
builtin-lock.c:2037:14: error: result of comparison of constant 18446744073709551615 with expression of type 'unsigned int' is always true [-Werror,-Wtautological-constant-out-of-range-compare]
if (flags != -1UL) {
~~~~~ ^ ~~~~
3 errors generated.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Blake Jones <blakejones@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20221219201732.460111-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock contention: Add -l/--lock-addr option

The -l/--lock-addr option is to implement per-lock-instance contention
stat using LOCK_AGGR_ADDR. It displays lock address and optionally
symbol name if exists.

$ sudo ./perf lock con -abl sleep 1
contended total wait max wait avg wait address symbol

1 36.28 us 36.28 us 36.28 us ffff92615d6448b8
9 10.91 us 1.84 us 1.21 us ffffffffbaed50c0 rcu_state
1 10.49 us 10.49 us 10.49 us ffff9262ac4f0c80
8 4.68 us 1.67 us 585 ns ffffffffbae07a40 jiffies_lock
3 3.03 us 1.45 us 1.01 us ffff9262277861e0
1 924 ns 924 ns 924 ns ffff926095ba9d20
1 436 ns 436 ns 436 ns ffff9260bfda4f60

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Blake Jones <blakejones@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20221209190727.759804-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf tools: Make quiet mode consistent between tools

Use the global quiet variable everywhere so that all tools hide warnings
in quiet mode and update the documentation to reflect this.

'perf probe' claimed that errors are not printed in quiet mode but I
don't see this so remove it from the docs.

Signed-off-by: James Clark <james.clark@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221018094137.783081-3-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock: Add -q/--quiet option to suppress header and debug messages

Like in 'perf report', this option is to suppress header and debug messages.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220924004221.841024-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock: Add -E/--entries option

Like in 'perf top', the -E option can limit number of entries to print.

It can be useful when users want to see top N contended locks only.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220924004221.841024-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock contention: Allow to change stack depth and skip

It needs stack traces to find callers of locks. To minimize the
performance overhead it only collects up to 8 entries for each stack
trace. And it skips first 3 entries as they came from BPF, tracepoint
and lock functions which are not interested for most users.

But it turned out that those numbers are different in some
configuration. Using fixed number can result in non meaningful caller
names. Let's make them adjustable with --stack-depth and --skip-stack
options.

On my setup, the default output is like below:

# /perf lock con -ab -F contended,wait_total sleep 3
contended total wait type caller

28 4.55 ms rwlock:W __bpf_trace_contention_begin+0xb
33 1.67 ms rwlock:W __bpf_trace_contention_begin+0xb
12 580.28 us spinlock __bpf_trace_contention_begin+0xb
60 240.54 us rwsem:R __bpf_trace_contention_begin+0xb
27 64.45 us spinlock __bpf_trace_contention_begin+0xb

If I change the stack skip to 5, the result will be like:

# perf lock con -ab -F contended,wait_total --stack-skip 5 sleep 3
contended total wait type caller

32 715.45 us spinlock folio_lruvec_lock_irqsave+0x61
26 550.22 us spinlock folio_lruvec_lock_irqsave+0x61
15 486.93 us rwsem:R mmap_read_lock+0x13
12 139.66 us rwsem:W vm_mmap_pgoff+0x93
1 7.04 us spinlock tick_do_update_jiffies64+0x25

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20220912055314.744552-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock: Add --map-nr-entries option

The --map-nr-entries option is to control number of max entries in the
perf lock contention BPF maps.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Blake Jones <blakejones@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220802191004.347740-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock: Implement cpu and task filters for BPF

Add -a/--all-cpus and -C/--cpu options for cpu filtering. Also -p/--pid
and --tid options are added for task filtering. The short -t option is
taken for --threads already. Tracking the command line workload is
possible as well.

$ sudo perf lock contention -a -b sleep 1

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Blake Jones <blakejones@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220729200756.666106-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock: Use BPF for lock contention analysis

Add -b/--use-bpf option to use BPF to collect lock contention stats.
For simplicity it now runs system-wide and requires C-c to stop.
Upcoming changes will add the usual filtering.

$ sudo perf lock con -b
^C
contended total wait max wait avg wait type caller

42 192.67 us 13.64 us 4.59 us spinlock queue_work_on+0x20
23 85.54 us 10.28 us 3.72 us spinlock worker_thread+0x14a
6 13.92 us 6.51 us 2.32 us mutex kernfs_iop_permission+0x30
3 11.59 us 10.04 us 3.86 us mutex kernfs_dop_revalidate+0x3c
1 7.52 us 7.52 us 7.52 us spinlock kthread+0x115
1 7.24 us 7.24 us 7.24 us rwlock:W sys_epoll_wait+0x148
2 7.08 us 3.99 us 3.54 us spinlock delayed_work_timer_fn+0x1b
1 6.41 us 6.41 us 6.41 us spinlock idle_balance+0xa06
2 2.50 us 1.83 us 1.25 us mutex kernfs_iop_lookup+0x2f
1 1.71 us 1.71 us 1.71 us mutex kernfs_iop_getattr+0x2c

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Blake Jones <blakejones@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220729200756.666106-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock: Support -t option for 'contention' subcommand

Like perf lock report, it can report lock contention stat of each task.

$ perf lock contention -t
contended total wait max wait avg wait pid comm

5 945.20 us 902.08 us 189.04 us 316167 EventManager_De
33 98.17 us 6.78 us 2.97 us 766063 kworker/0:1-get
7 92.47 us 61.26 us 13.21 us 316170 EventManager_De
14 76.31 us 12.87 us 5.45 us 12949 timedcall
24 76.15 us 12.27 us 3.17 us 767992 sched-pipe
15 75.62 us 11.93 us 5.04 us 15127 switchto-defaul
24 71.84 us 5.59 us 2.99 us 629168 kworker/u513:2-
17 67.41 us 7.94 us 3.96 us 13504 coroner-
1 59.56 us 59.56 us 59.56 us 316165 EventManager_De
14 56.21 us 6.89 us 4.01 us 0 swapper

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220725183124.368304-6-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock: Add -k and -F options to 'contention' subcommand

Like perf lock report, add -k/--key and -F/--field options to control
output formatting and sorting. Note that it has slightly different
default options as some fields are not available and to optimize the
screen space.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220725183124.368304-5-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock: Add 'contention' subcommand

The 'perf lock contention' processes the lock contention events and
displays the result like perf lock report. Right now, there's not
much difference between the two but the lock contention specific
features will come soon.

$ perf lock contention
contended total wait max wait avg wait type caller

238 1.41 ms 29.20 us 5.94 us spinlock update_blocked_averages+0x4c
1 902.08 us 902.08 us 902.08 us rwsem:R do_user_addr_fault+0x1dd
81 330.30 us 17.24 us 4.08 us spinlock _nohz_idle_balance+0x172
2 89.54 us 61.26 us 44.77 us spinlock do_anonymous_page+0x16d
24 78.36 us 12.27 us 3.27 us mutex pipe_read+0x56
2 71.58 us 59.56 us 35.79 us spinlock __handle_mm_fault+0x6aa
6 25.68 us 6.89 us 4.28 us spinlock do_idle+0x28d
1 18.46 us 18.46 us 18.46 us rtmutex exec_fw_cmd+0x21b
3 15.25 us 6.26 us 5.08 us spinlock tick_do_update_jiffies64+0x2c

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220725183124.368304-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock: Allow to use different kernel symbols

Add --vmlinux and --kallsyms options to support data file from
different kernels.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220615163222.1275500-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock: Add -t/--thread option for report

The -t option is to show per-thread lock stat like below:

$ perf lock report -t -F acquired,contended,avg_wait

Name acquired contended avg wait (ns)

perf 240569 9 5784
swapper 106610 19 543
:15789 17370 2 14538
ContainerMgr 8981 6 874
sleep 5275 1 11281
ContainerThread 4416 4 944
RootPressureThr 3215 5 1215
rcu_preempt 2954 0 0
ContainerMgr 2560 0 0
unnamed 1873 0 0
EventManager_De 1845 1 636
futex-default-S 1609 0 0
...

Committer notes:

Add that option to the 'perf lock report' man page.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220521010811.932703-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock: Add -F/--field option to control output

The -F/--field option is to customize the list of fields to output:

$ perf lock report -F contended,wait_max -k avg_wait
Name contended max wait (ns) avg wait (ns)

slock-AF_INET6 1 23543 23543
&lruvec->lru_lock 5 18317 11254
slock-AF_INET6 1 10379 10379
rcu_node_1 1 2104 2104
&dentry->d_lockr... 1 1844 1844
&dentry->d_lockr... 1 1672 1672
&newf->file_lock 15 2279 1025
&dentry->d_lockr... 1 792 792

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220323230259.288494-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock: Add -c/--combine-locks option

The -c or --combine-locks option is to merge lock instances in the
same class into a single entry. It compares the name of the locks
and marks duplicated entries using lock_stat->combined.

# perf lock report
Name acquired contended avg wait (ns) total wait (ns) max wait (ns) min wait (ns)

rcu_read_lock 251225 0 0 0 0 0
&(ei->i_block_re... 8731 0 0 0 0 0
&sb->s_type->i_l... 8731 0 0 0 0 0
hrtimer_bases.lock 5261 0 0 0 0 0
hrtimer_bases.lock 2626 0 0 0 0 0
hrtimer_bases.lock 1953 0 0 0 0 0
hrtimer_bases.lock 1382 0 0 0 0 0
cpu_hotplug_lock 1350 0 0 0 0 0
hrtimer_bases.lock 1273 0 0 0 0 0
hrtimer_bases.lock 1269 0 0 0 0 0

# perf lock report -c
Name acquired contended avg wait (ns) total wait (ns) max wait (ns) min wait (ns)

rcu_read_lock 251225 0 0 0 0 0
hrtimer_bases.lock 39450 0 0 0 0 0
&sb->s_type->i_l... 10301 1 662 662 662 662
ptlock_ptr(page) 10173 2 701 1402 760 642
&(ei->i_block_re... 8732 0 0 0 0 0
&xa->xa_lock 8088 0 0 0 0 0
&base->lock 6705 0 0 0 0 0
&p->pi_lock 5549 0 0 0 0 0
&dentry->d_lockr... 5010 4 1274 5097 1844 789
&ep->lock 3958 0 0 0 0 0

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220127000050.3011493-6-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf doc: Fix typos all over the place

Considering that perf and its subcommands have so many parameters, the
documentation is always the first stop for perf beginners. Fixing some
spelling errors will relax the eyes of some readers a little bit.

s/specicfication/specification/
s/caheline/cacheline/
s/tranasaction/transaction/
s/complan/complain/
s/sched_wakep/sched_wakeup/
s/possble/possible/
s/methology/methodology/

Signed-off-by: Like Xu <likexu@tencent.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20210924081942.38368-1-likexu@tencent.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock: Document missing options

Add man page entry for --force.

Signed-off-by: Sihyeon Jang <uneedsihyeon@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1510837609-6277-1-git-send-email-uneedsihyeon@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock: Account for lock average wait time

While perf-lock currently reports both the total wait time and the
number of contentions, it doesn't explicitly show the average wait time.
Having this value immediately in the report can be quite useful when
looking into performance issues.

Furthermore, allowing report to sort by averages is another handy
feature to have - and thus do not only print the value, but add it to
the lock_stat structure.

Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1378693159-8747-8-git-send-email-davidlohr@hp.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock: Document lock info subcommand

The commit 26242d859c9be ("perf lock: Add "info" subcommand for dumping
misc information") added the subcommand but missed documentation. Add
it. Also update stale 'trace' subcommand to 'script'.

Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1327827356-8786-5-git-send-email-namhyung@gmail.com
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf report: Accept fifos as input file

The default input file for perf report is not handled the same way as
perf record does it for its output file. This leads to unexpected
behavior of perf report, etc. E.g.:

# perf record -a -e cpu-cycles sleep 2 | perf report | cat
failed to open perf.data: No such file or directory (try 'perf record' first)

While perf record writes to a fifo, perf report expects perf.data to be
read. This patch changes this to accept fifos as input file.

Applies to the following commands:

perf annotate
perf buildid-list
perf evlist
perf kmem
perf lock
perf report
perf sched
perf script
perf timechart

Also fixes char const* -> const char* type declaration for filename
strings.

v2:
* Prevent potential null pointer access to input_name in
builtin-report.c. Needed due to removal of patch "perf report: Setup
browser if stdout is a pipe"

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1323248577-11268-5-git-send-email-robert.richter@amd.com
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock: Document valid sort keys

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110222205312.GA18474@joi.lan>
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock: Document missing options

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1291168642-11402-7-git-send-email-shawn.bohrer@gmail.com>
Signed-off-by: Shawn Bohrer <shawn.bohrer@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf lock: Fix and add misc documentally things

I've forgot to add 'perf lock' line to command-list.txt,
so users of perf could not find perf lock when they type 'perf'.

Fixing command-list.txt requires document
(tools/perf/Documentation/perf-lock.txt).
But perf lock is too much "under construction" to write a
stable document, so this is something like pseudo document for now.

And I wrote description of perf lock at help section of
CONFIG_LOCK_STAT, this will navigate users of lock trace events.

Signed-off-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
LKML-Reference: <1265267295-8388-1-git-send-email-mitake@dcl.info.waseda.ac.jp>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>