perf tools: Add missing else to cmd_daemon subcommand condition

Namhyung reported segfault in perf daemon start command.

It's caused by extra check on argv[0] which is set to NULL by previous
__cmd_start call. Adding missing else to skip the extra check.

Fixes: 92294b906e6c ("perf daemon: Dynamically allocate path to perf")
Reported-and-Tested-by: Namhyung Kim <namhyung@kernel.org>
Reported-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/r/20230626201606.2514679-1-jolsa@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

perf daemon: Dynamically allocate path to perf

Avoid a PATH_MAX array in __daemon (the .data section) by dynamically
allocating the memory.

Signed-off-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20230526183401.2326121-9-irogers@google.com
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ross Zwisler <zwisler@chromium.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Yang Jihong <yangjihong1@huawei.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: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Use zfree() to reduce chances of use after free

Do defensive programming by using zfree() to initialize freed pointers
to NULL, so that eventual use after free result in a NULL pointer deref
instead of more subtle behaviour.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Use sig_atomic_t to avoid UB

Use sig_atomic_t for a variable written to in a signal handler and
read elsewhere. This is undefined behavior as per:

https://wiki.sei.cmu.edu/confluence/display/c/SIG31-C.+Do+not+access+shared+objects+in+signal+handlers

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
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: https://lore.kernel.org/r/20221024181913.630986-4-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Complete list of supported subcommand in help message

perf daemon supports start, signal, stop and ping subcommands, complete it

Before:

# perf daemon -h
Usage: perf daemon start [<options>]
or: perf daemon [<options>]

-v, --verbose be more verbose
-x, --field-separator[=<field separator>]
print counts with custom separator
--base <directory>
base directory
--config <config file>
config file path

After:

# perf daemon -h

Usage: perf daemon {start|signal|stop|ping} [<options>]
or: perf daemon [<options>]

-v, --verbose be more verbose
-x, --field-separator[=<field separator>]
print counts with custom separator
--base <directory>
base directory
--config <config file>
config file path

Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.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/20221022092735.114967-3-yangjihong1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Remove duplicate sys/file.h include

There is a "#include <sys/file.h>" in line 10, so remove a duplicate
one in line 1124.

Signed-off-by: Guo Zhengkui <guozhengkui@vivo.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20211006062235.6364-1-guozhengkui@vivo.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Avoid msan warnings on send_cmd

As a full union is always sent, ensure all bytes of the union are
initialized with memset to avoid msan warnings of use of uninitialized
memory.

An example warning from the daemon test:

Uninitialized bytes in __interceptor_write at offset 71 inside [0x7ffd98da6280, 72)
==11602==WARNING: MemorySanitizer: use-of-uninitialized-value
#0 0x5597edccdbe4 in ion tools/lib/perf/lib.c:18:6
#1 0x5597edccdbe4 in writen tools/lib/perf/lib.c:47:9
#2 0x5597ed221d30 in send_cmd tools/perf/builtin-daemon.c:1376:22
#3 0x5597ed21b48c in cmd_daemon tools/perf/builtin-daemon.c
#4 0x5597ed1d6b67 in run_builtin tools/perf/perf.c:313:11
#5 0x5597ed1d6036 in handle_internal_command tools/perf/perf.c:365:8
#6 0x5597ed1d6036 in run_argv tools/perf/perf.c:409:2
#7 0x5597ed1d6036 in main tools/perf/perf.c:539:3

SUMMARY: MemorySanitizer: use-of-uninitialized-value tools/lib/perf/lib.c:18:6 in ion
Exiting

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210617055554.1917997-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Remove duplicate includes

sys/stat.h has been included at line 23, so remove the
duplicate one at line 27.

linux/string.h has been included at line 7, so remove the
duplicate one at line 9.

time.h has been included at line 14, so remove the
duplicate one at line 28.

Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: kael_w@yeah.net
Link: http://lore.kernel.org/lkml/20210323050139.287461-1-wanjiabing@vivo.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Return from kill functions

We should return correctly and warn in both daemon_session__kill() and
daemon__kill() after we tried everything to kill sessions. The current
code will keep on looping and waiting.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210320221013.1619613-2-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Force waipid for all session on SIGCHLD delivery

If we don't process SIGCHLD before another comes, we will see just one
SIGCHLD as a result. In this case current code will miss exit
notification for a session and wait forever.

Adding extra waitpid check for all sessions when SIGCHLD is received, to
make sure we don't miss any session exit.

Also fix close condition for signal_fd.

Reported-by: Ian Rogers <irogers@google.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210320221013.1619613-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Fix compile error with Asan

I'm seeing a build failure when build with address sanitizer. It seems
we could write to the name[100] if the var is longer.

$ make EXTRA_CFLAGS=-fsanitize=address
...
CC builtin-daemon.o
In function ‘get_session_name’,
inlined from ‘session_config’ at builtin-daemon.c:164:6,
inlined from ‘server_config’ at builtin-daemon.c:223:10:
builtin-daemon.c:155:11: error: writing 1 byte into a region of size 0 [-Werror=stringop-overflow=]
155 | *session = 0;
| ~~~~~~~~~^~~
builtin-daemon.c: In function ‘server_config’:
builtin-daemon.c:162:7: note: at offset 100 to object ‘name’ with size 100 declared here
162 | char name[100];
| ^~~~

Fixes: c0666261ff38 ("perf daemon: Add config file support")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210224071438.686677-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Fix control fifo permissions

Add proper mode for mkfifo calls to get read and write permissions for
user. We can't use O_RDWR in here, changing to standard permission
value.

Fixes: 6a6d1804a190 ("perf daemon: Set control fifo for session")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210301122510.64402-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Add up time for daemon/session list

Display up time for both daemon and sessions.

Example:

# cat ~/.perfconfig
[daemon]
base=/opt/perfdata

[session-cycles]
run = -m 10M -e cycles --overwrite --switch-output -a

[session-sched]
run = -m 20M -e sched:* --overwrite --switch-output -a

Starting the daemon:

# perf daemon start

Get the details with up time:

# perf daemon -v
[778315:daemon] base: /opt/perfdata
output: /opt/perfdata/output
lock: /opt/perfdata/lock
up: 15 minutes
[778316:cycles] perf record -m 20M -e cycles --overwrite --switch-output -a
base: /opt/perfdata/session-cycles
output: /opt/perfdata/session-cycles/output
control: /opt/perfdata/session-cycles/control
ack: /opt/perfdata/session-cycles/ack
up: 10 minutes
[778317:sched] perf record -m 20M -e sched:* --overwrite --switch-output -a
base: /opt/perfdata/session-sched
output: /opt/perfdata/session-sched/output
control: /opt/perfdata/session-sched/control
ack: /opt/perfdata/session-sched/ack
up: 2 minutes

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20210208200908.1019149-18-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Use control to stop session

Use the 'stop' control command to stop perf record session. If that
fails, fall back to current SIGTERM/SIGKILL pair.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20210208200908.1019149-17-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Add 'ping' command

Add a 'ping' command to verify that the 'perf record' session is up and
operational.

It's used in the following patches via test code to make sure 'perf
record' is ready to receive signals.

Example:

# cat ~/.perfconfig
[daemon]
base=/opt/perfdata

[session-cycles]
run = -m 10M -e cycles --overwrite --switch-output -a

[session-sched]
run = -m 20M -e sched:* --overwrite --switch-output -a

Start the daemon:

# perf daemon start

Ping all sessions:

# perf daemon ping
OK cycles
OK sched

Ping specific session:

# perf daemon ping --session sched
OK sched

Committer notes:

Fixed up bug pointed by clang:

Buggy:

if (!pollfd.revents & POLLIN)

Correct code:

if (!(pollfd.revents & POLLIN))

clang warning:

builtin-daemon.c:560:6: error: logical not is only applied to the left hand side of this bitwise operator [-Werror,-Wlogical-not-parentheses]
if (!pollfd.revents & POLLIN) {
^ ~
builtin-daemon.c:560:6: note: add parentheses after the '!' to evaluate the bitwise operator first

Also use designated initialized with pollfd, i.e.:

struct pollfd pollfd = { .events = POLLIN, };

Instead of:

struct pollfd pollfd = { 0, };

To get past:

builtin-daemon.c:510:30: error: missing field 'events' initializer [-Werror,-Wmissing-field-initializers]
struct pollfd pollfd = { 0, };
^
1 error generated.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20210208200908.1019149-16-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Set control fifo for session

Setup control fifos for session and add --control option to session
arguments.

Example:

# cat ~/.perfconfig
[daemon]
base=/opt/perfdata

[session-cycles]
run = -m 10M -e cycles --overwrite --switch-output -a

[session-sched]
run = -m 20M -e sched:* --overwrite --switch-output -a

Starting the daemon:

# perf daemon start

Use can list control fifos with (control and ack files):

# perf daemon -v
[776459:daemon] base: /opt/perfdata
output: /opt/perfdata/output
lock: /opt/perfdata/lock
[776460:cycles] perf record -m 20M -e cycles --overwrite --switch-output -a
base: /opt/perfdata/session-cycles
output: /opt/perfdata/session-cycles/output
control: /opt/perfdata/session-cycles/control
ack: /opt/perfdata/session-cycles/ack
[776461:sched] perf record -m 20M -e sched:* --overwrite --switch-output -a
base: /opt/perfdata/session-sched
output: /opt/perfdata/session-sched/output
control: /opt/perfdata/session-sched/control
ack: /opt/perfdata/session-sched/ack

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20210208200908.1019149-15-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Allow only one daemon over base directory

Add 'lock' file under daemon base and flock it, so only one perf daemon
can run on top of it.

Each daemon tries to create and lock BASE/lock file, if it's successful
we are sure we're the only daemon running over the BASE.

Once daemon is finished, file descriptor to lock file is closed and lock
is released.

Example:

# cat ~/.perfconfig
[daemon]
base=/opt/perfdata

[session-cycles]
run = -m 10M -e cycles --overwrite --switch-output -a

[session-sched]
run = -m 20M -e sched:* --overwrite --switch-output -a

Starting the daemon:

# perf daemon start

And try once more:

# perf daemon start
failed: another perf daemon (pid 775594) owns /opt/perfdata

will end up with an error, because there's already one running
on top of /opt/perfdata.

Committer notes:

Provide lockf(F_TLOCK) when not available, i.e. transform:

lockf(fd, F_TLOCK, 0);

into:

flock(fd, LOCK_EX | LOCK_NB);

Which should be equivalent.

Noticed when cross building to some odd Android NDK.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20210208200908.1019149-14-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Add 'stop' command

Add 'perf daemon stop' command to stop daemon process and all running
sessions.

Example:

# cat ~/.perfconfig
[daemon]
base=/opt/perfdata

[session-cycles]
run = -m 10M -e cycles --overwrite --switch-output -a

[session-sched]
run = -m 20M -e sched:* --overwrite --switch-output -a

Start the daemon:

# perf daemon start

Stop the daemon

# perf daemon stop

Daemon is not running, nothing to connect to:

# perf daemon
connect error: Connection refused

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20210208200908.1019149-13-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Add 'signal' command

Allow the 'perf daemon' to send SIGUSR2 to all running sessions or just
to a specific session.

Example:

# cat ~/.perfconfig
[daemon]
base=/opt/perfdata

[session-cycles]
run = -m 10M -e cycles --overwrite --switch-output -a

[session-sched]
run = -m 20M -e sched:* --overwrite --switch-output -a

Start the daemon:

# perf daemon start

Send signal to all running sessions:

# perf daemon signal
signal 12 sent to session 'cycles [773738]'
signal 12 sent to session 'sched [773739]'

Or to specific one:

# perf daemon signal --session sched
signal 12 sent to session 'sched [773739]'

And verify signals were delivered and perf.data dumped:

# cat /opt/perfdata/session-cycles/output
rounding mmap pages size to 32M (8192 pages)
[ perf record: dump data: Woken up 1 times ]
[ perf record: Dump perf.data.2021010220382490 ]

# car /opt/perfdata/session-sched/output
rounding mmap pages size to 32M (8192 pages)
[ perf record: dump data: Woken up 1 times ]
[ perf record: Dump perf.data.2021010220382489 ]
[ perf record: dump data: Woken up 1 times ]
[ perf record: Dump perf.data.2021010220393745 ]

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20210208200908.1019149-12-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Add 'list' command

Add a 'list' command to display all running sessions. It's the default
command if no other command is specified.

Example:

# cat ~/.perfconfig
[daemon]
base=/opt/perfdata

[session-cycles]
run = -m 10M -e cycles --overwrite --switch-output -a

[session-sched]
run = -m 20M -e sched:* --overwrite --switch-output -a

Start the daemon:

# perf daemon start

List sessions:

# perf daemon
[771394:daemon] base: /opt/perfdata
[771395:cycles] perf record -m 10M -e cycles --overwrite --switch-output -a
[771396:sched] perf record -m 20M -e sched:* --overwrite --switch-output -a

List sessions with more info:

# perf daemon -v
[771394:daemon] base: /opt/perfdata
output: /opt/perfdata/output
[771395:cycles] perf record -m 10M -e cycles --overwrite --switch-output -a
base: /opt/perfdata/session-cycles
output: /opt/perfdata/session-cycles/output
[771396:sched] perf record -m 20M -e sched:* --overwrite --switch-output -a
base: /opt/perfdata/session-sched
output: /opt/perfdata/session-sched/output

The 'output' file is perf record output for specific session.

Note you have to stop all running perf processes manually at this point,
stop command is coming in following patches.

Committer notes:

Fixup union initialization to overcome this in multiple older systems:

22 15.74 debian:8 : FAIL gcc version 4.9.2 (Debian 4.9.2-10+deb8u2)

builtin-daemon.c: In function 'send_cmd_list':
builtin-daemon.c:1386:2: error: missing initializer for field 'csv_sep' of 'struct <anonymous>' [-Werror=missing-field-initializers]
};
^
builtin-daemon.c:641:8: note: 'csv_sep' declared here
char csv_sep;
^
cc1: all warnings being treated as errors

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20210208200908.1019149-11-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Add signalfd support

Use a signalfd fd to track SIGCHLD signals as notifications for perf
session termination.

This way we don't need to actively check for child status, being
notified if there's change.

Suggested-by: Alexei Budankov <abudankov@huawei.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20210208200908.1019149-10-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Add background support

Add support to put the daemon process in the background.

It's now enabled by default and -f option is added to keep the daemon
process on the console for debugging.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20210208200908.1019149-9-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Add config file change check

Add support to detect changes to the daemon's config file triggering a
re-read of the configuration when that happens.

Use a inotify file descriptor plugged into the main fdarray object for
polling.

Example:

# cat ~/.perfconfig
[daemon]
base=/opt/perfdata

[session-cycles]
run = -m 10M -e cycles --overwrite --switch-output -a

Starting the daemon:

# perf daemon start

Check sessions:

# perf daemon
[772262:daemon] base: /opt/perfdata
[772263:cycles] perf record -m 10M -e cycles --overwrite --switch-output -a

Change '-m 10M' to '-m 20M', and check daemon log:

# tail -f /opt/perfdata/output
[2021-01-02 20:31:41.234045] daemon started (pid 772262)
[2021-01-02 20:31:41.235072] reconfig: ruining session [cycles:772263]: -m 10M -e cycles --overwrite --switch-output -a
[2021-01-02 20:32:08.310137] reconfig: session 'cycles' killed
[2021-01-02 20:32:08.310847] reconfig: ruining session [cycles:772338]: -m 20M -e cycles --overwrite --switch-output -a

And the session list:

# perf daemon
[772262:daemon] base: /opt/perfdata
[772338:cycles] perf record -m 20M -e cycles --overwrite --switch-output -a

Note the changed '-m 20M' option is in place.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20210208200908.1019149-8-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Add config file support

Adding support to configure daemon with config file.

Each client or server invocation of perf daemon needs to know the
base directory, where all sessions data is stored.

The base is defined with:

daemon.base
Base path for daemon data. All sessions data are stored under
this path.

The daemon allows to create record sessions. Each session is a
record command spawned and monitored by perf daemon.

The session is defined with:

session-<NAME>.run
Defines new record session for daemon. The value is record's
command line without the 'record' keyword.

Example:

# cat ~/.perfconfig
[daemon]
base=/opt/perfdata

[session-cycles]
run = -m 10M -e cycles --overwrite --switch-output -a

[session-sched]
run = -m 20M -e sched:* --overwrite --switch-output -a

The example above defines '/opt/perfdata' as the base directory and 2
record sessions.

# perf daemon start
[2021-01-28 19:47:33.454413] daemon started (pid 16015)
[2021-01-28 19:47:33.455910] reconfig: ruining session [cycles:16016]: -m 10M -e cycles --overwrite --switch-output -a
[2021-01-28 19:47:33.456599] reconfig: ruining session [sched:16017]: -m 20M -e sched:* --overwrite --switch-output -a

# ps -ef | grep perf
... perf daemon start
... /home/jolsa/.../perf record -m 20M -e cycles --overwrite --switch-output -a
... /home/jolsa/.../perf record -m 20M -e sched:* --overwrite --switch-output -a

The base directory is populated with:

# find /opt/perfdata/
/opt/perfdata/
/opt/perfdata/control <- control socket
/opt/perfdata/session-cycles <- data for session 'cycles':
/opt/perfdata/session-cycles/output <- perf record output
/opt/perfdata/session-cycles/perf.data <- perf data
/opt/perfdata/session-sched <- ditto for session 'sched'
/opt/perfdata/session-sched/output
/opt/perfdata/session-sched/perf.data

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20210208200908.1019149-7-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Add client socket support

Add support for client socket side that will be used to send commands to
the daemon server socket.

This patch adds only the core support, all commands using this
functionality are coming in the following patches.

Committer notes:

Hat to patch patch it to deal with this in some systems:

cc1: warnings being treated as errors
builtin-daemon.c: In function 'send_cmd': MKDIR /tmp/build/perf/bench/

builtin-daemon.c:1368: error: ignoring return value of 'fwrite', declared with attribute warn_unused_result
MKDIR /tmp/build/perf/tests/
make[3]: *** [/tmp/build/perf/builtin-daemon.o] Error 1

And also to not leak the 'line' buffer allocated by getline(), since you
initialized line to NULL and len to zero, man page says:

If *lineptr is set to NULL and *n is set 0 before the call,
then getline() will allocate a buffer for storing the line.
This buffer should be freed by the user program even if
getline() failed.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20210208200908.1019149-6-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Add server socket support

Add support to create a server socket that listens for client commands
and processes them.

This patch adds only the core support, all commands using this
functionality are coming in the following patches.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20210208200908.1019149-5-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Add base option

Add a base option allowing the user to specify a base directory. It
will have precedence over config file base definition coming in the
following patches.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20210208200908.1019149-4-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Add config option

Add a config option and base functionality that takes the option
argument (if specified) and other system config locations and produces
an 'acting' config file path.

The actual config file processing is coming in following patches.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20210208200908.1019149-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf daemon: Add daemon command

Add a daemon skeleton with a minimal base (non) functionality, covering
various setup in start command.

Add an initial perf-daemon.txt with basic info.

This is in response to pople asking for the possibility to be able run
record long running sessions on the background.

The patchset that starts with this adds support to configure and run
record sessions on background via new 'perf daemon' command.

This is useful for being able to use perf as a flight recorder that one
can interact with asking for events to be enabled or disabled, added or
removed, etc.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20210208200908.1019149-2-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>