Remove the LIBTRACEEVENT_DYNAMIC and LIBTRACEFS_DYNAMIC make command
line variables.
If libtraceevent isn't installed or NO_LIBTRACEEVENT=1 is passed to the
build, don't compile in libtraceevent and libtracefs support.
This also disables CONFIG_TRACE that controls "perf trace".
CONFIG_LIBTRACEEVENT is used to control enablement in Build/Makefiles,
HAVE_LIBTRACEEVENT is used in C code.
Without HAVE_LIBTRACEEVENT tracepoints are disabled and as such the
commands kmem, kwork, lock, sched and timechart are removed. The
majority of commands continue to work including "perf test".
Committer notes:
Fixed up a tools/perf/util/Build reject and added:
#include <traceevent/event-parse.h>
to tools/perf/util/scripting-engines/trace-event-perl.c.
Committer testing:
$ rpm -qi libtraceevent-devel
Name : libtraceevent-devel
Version : 1.5.3
Release : 2.fc36
Architecture: x86_64
Install Date: Mon 25 Jul 2022 03:20:19 PM -03
Group : Unspecified
Size : 27728
License : LGPLv2+ and GPLv2+
Signature : RSA/SHA256, Fri 15 Apr 2022 02:11:58 PM -03, Key ID 999f7cbf38ab71f4
Source RPM : libtraceevent-1.5.3-2.fc36.src.rpm
Build Date : Fri 15 Apr 2022 10:57:01 AM -03
Build Host : buildvm-x86-05.iad2.fedoraproject.org
Packager : Fedora Project
Vendor : Fedora Project
URL : https://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git/
Bug URL : https://bugz.fedoraproject.org/libtraceevent
Summary : Development headers of libtraceevent
Description :
Development headers of libtraceevent-libs
$
Default build:
$ ldd ~/bin/perf | grep tracee
libtraceevent.so.1 => /lib64/libtraceevent.so.1 (0x00007f1dcaf8f000)
$
# perf trace -e sched:* --max-events 10
0.000 migration/0/17 sched:sched_migrate_task(comm: "", pid: 1603763 (perf), prio: 120, dest_cpu: 1)
0.005 migration/0/17 sched:sched_wake_idle_without_ipi(cpu: 1)
0.011 migration/0/17 sched:sched_switch(prev_comm: "", prev_pid: 17 (migration/0), prev_state: 1, next_comm: "", next_prio: 120)
1.173 :0/0 sched:sched_wakeup(comm: "", pid: 3138 (gnome-terminal-), prio: 120)
1.180 :0/0 sched:sched_switch(prev_comm: "", prev_prio: 120, next_comm: "", next_pid: 3138 (gnome-terminal-), next_prio: 120)
0.156 migration/1/21 sched:sched_migrate_task(comm: "", pid: 1603763 (perf), prio: 120, orig_cpu: 1, dest_cpu: 2)
0.160 migration/1/21 sched:sched_wake_idle_without_ipi(cpu: 2)
0.166 migration/1/21 sched:sched_switch(prev_comm: "", prev_pid: 21 (migration/1), prev_state: 1, next_comm: "", next_prio: 120)
1.183 :0/0 sched:sched_wakeup(comm: "", pid: 1602985 (kworker/u16:0-f), prio: 120, target_cpu: 1)
1.186 :0/0 sched:sched_switch(prev_comm: "", prev_prio: 120, next_comm: "", next_pid: 1602985 (kworker/u16:0-f), next_prio: 120)
#
Had to tweak tools/perf/util/setup.py to make sure the python binding
shared object links with libtraceevent if -DHAVE_LIBTRACEEVENT is
present in CFLAGS.
Building with NO_LIBTRACEEVENT=1 uncovered some more build failures:
- Make building of data-convert-bt.c to CONFIG_LIBTRACEEVENT=y
- perf-$(CONFIG_LIBTRACEEVENT) += scripts/
- bpf_kwork.o needs also to be dependent on CONFIG_LIBTRACEEVENT=y
- The python binding needed some fixups and util/trace-event.c can't be
built and linked with the python binding shared object, so remove it
in tools/perf/util/setup.py and exclude it from the list of
dependencies in the python/perf.so Makefile.perf target.
Building without libtraceevent-devel installed uncovered more build
failures:
- The python binding tools/perf/util/python.c was assuming that
traceevent/parse-events.h was always available, which was the case
when we defaulted to using the in-kernel tools/lib/traceevent/ files,
now we need to enclose it under ifdef HAVE_LIBTRACEEVENT, just like
the other parts of it that deal with tracepoints.
- We have to ifdef the rules in the Build files with
CONFIG_LIBTRACEEVENT=y to build builtin-trace.c and
tools/perf/trace/beauty/ as we only ifdef setting CONFIG_TRACE=y when
setting NO_LIBTRACEEVENT=1 in the make command line, not when we don't
detect libtraceevent-devel installed in the system. Simplification here
to avoid these two ways of disabling builtin-trace.c and not having
CONFIG_TRACE=y when libtraceevent-devel isn't installed is the clean
way.
From Athira:
<quote>
tools/perf/arch/powerpc/util/Build
-perf-y += kvm-stat.o
+perf-$(CONFIG_LIBTRACEEVENT) += kvm-stat.o
</quote>
Then, ditto for arm64 and s390, detected by container cross build tests.
- s/390 uses test__checkevent_tracepoint() that is now only available if
HAVE_LIBTRACEEVENT is defined, enclose the callsite with ifder HAVE_LIBTRACEEVENT.
Also from Athira:
<quote>
With this change, I could successfully compile in these environment:
- Without libtraceevent-devel installed
- With libtraceevent-devel installed
- With “make NO_LIBTRACEEVENT=1”
</quote>
Then, finally rename CONFIG_TRACEEVENT to CONFIG_LIBTRACEEVENT for
consistency with other libraries detected in tools/perf/.
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Athira Rajeev <atrajeev@linux.vnet.ibm.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>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: bpf@vger.kernel.org
Link: http://lore.kernel.org/lkml/20221205225940.3079667-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The recent kernel added lost count can be read from either read(2) or
ring buffer data with PERF_SAMPLE_READ. As it's a variable length data
we need to access it according to the format info.
But for perf tools use cases, PERF_FORMAT_ID is always set. So we can
only check PERF_FORMAT_LOST bit to determine the data format.
Add sample_read_value_size() and next_sample_read_value() helpers to
make it a bit easier to access. Use them in all places where it reads
the struct sample_read_value.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220819003644.508916-5-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
A mask encoding of a cpu map is laid out as:
u16 nr
u16 long_size
unsigned long mask[];
However, the mask may be 8-byte aligned meaning there is a 4-byte pad
after long_size. This means 32-bit and 64-bit builds see the mask as
being at different offsets. On top of this the structure is in the byte
data[] encoded as:
u16 type
char data[]
This means the mask's struct isn't the required 4 or 8 byte aligned, but
is offset by 2. Consequently the long reads and writes are causing
undefined behavior as the alignment is broken.
Fix the mask struct by creating explicit 32 and 64-bit variants, use a
union to avoid data[] and casts; the struct must be packed so the
layout matches the existing perf.data layout. Taking an address of a
member of a packed struct breaks alignment so pass the packed
perf_record_cpu_map_data to functions, so they can access variables with
the right alignment.
As the 64-bit version has 4 bytes of padding, optimizing writing to only
write the 32-bit version.
Committer notes:
Disable warnings about 'packed' that break the build in some arches like
riscv64, but just around that specific struct.
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
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: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: Colin Ian King <colin.king@intel.com>
Cc: Dave Marchevsky <davemarchevsky@fb.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Kees Kook <keescook@chromium.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: Riccardo Mancini <rickyman7@gmail.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20220614143353.1559597-5-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When injecting events from a guest perf.data file, the events will have
separate sample ID numbers. These ID numbers can then be used to determine
which machine an event belongs to. To facilitate that, add machine_pid and
vcpu to id_index records. For backward compatibility, these are added at
the end of the record, and the length of the record is used to determine
if they are present or not.
Note, this is needed because the events from a guest perf.data file contain
the pid/tid of the process running at that time inside the VM not the
pid/tid of the (QEMU) hypervisor thread. So a way is needed to relate
guest events back to the guest machine and VCPU, and using sample ID
numbers for that is relatively simple and convenient.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: kvm@vger.kernel.org
Link: https://lore.kernel.org/r/20220711093218.10967-11-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To update the perf/core codebase.
Fix conflict by moving arch__post_evsel_config(evsel, attr) to the end
of evsel__config(), after what was added in:
49c692b7df ("perf offcpu: Accept allowed sample types only")
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
For perf recording, it retrieves process info by iterating nodes in proc
fs. If we run perf in a non-root PID namespace with command:
# unshare --fork --pid perf record -e cycles -a -- test_program
... in this case, unshare command creates a child PID namespace and
launches perf tool in it, but the issue is the proc fs is not mounted
for the non-root PID namespace, this leads to the perf tool gathering
process info from its parent PID namespace.
We can use below command to observe the process nodes under proc fs:
# unshare --pid --fork ls /proc
1 137 1968 2128 3 342 48 62 78 crypto kcore net uptime
10 138 2 2142 30 35 49 63 8 devices keys pagetypeinfo version
11 139 20 2143 304 36 50 64 82 device-tree key-users partitions vmallocinfo
12 14 2011 22 305 37 51 65 83 diskstats kmsg self vmstat
128 140 2038 23 307 39 52 656 84 driver kpagecgroup slabinfo zoneinfo
129 15 2074 24 309 4 53 67 9 execdomains kpagecount softirqs
13 16 2094 241 31 40 54 68 asound fb kpageflags stat
130 164 2096 242 310 41 55 69 buddyinfo filesystems loadavg swaps
131 17 2098 25 317 42 56 70 bus fs locks sys
132 175 21 26 32 43 57 71 cgroups interrupts meminfo sysrq-trigger
133 179 2102 263 329 44 58 75 cmdline iomem misc sysvipc
134 1875 2103 27 330 45 59 76 config.gz ioports modules thread-self
135 19 2117 29 333 46 6 77 consoles irq mounts timer_list
136 1941 2121 298 34 47 60 773 cpuinfo kallsyms mtd tty
So it shows many existed tasks, since unshared command has not mounted
the proc fs for the new created PID namespace, it still accesses the
proc fs of the root PID namespace. This leads to two prominent issues:
- Firstly, PID values are mismatched between thread info and samples.
The gathered thread info are coming from the proc fs of the root PID
namespace, but samples record its PID from the child PID namespace.
- The second issue is profiled program 'test_program' returns its forked
PID number from the child PID namespace, perf tool wrongly uses this
PID number to retrieve the process info via the proc fs of the root
PID namespace.
To avoid issues, we need to mount proc fs for the child PID namespace
with the option '--mount-proc' when use unshare command:
# unshare --fork --pid --mount-proc perf record -e cycles -a -- test_program
Conversely, when the proc fs of the root PID namespace is used by child
namespace, perf tool can detect the multiple PID levels and
nsinfo__is_in_root_namespace() returns false, this patch reports error
for this case:
# unshare --fork --pid perf record -e cycles -a -- test_program
Couldn't synthesize bpf events.
Perf runs in non-root PID namespace but it tries to gather process info from its parent PID namespace.
Please mount the proc file system properly, e.g. add the option '--mount-proc' for unshare command.
Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20211224124014.2492751-1-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When the input is a regular file but the output is a pipe, it should
write a pipe header. But just repiping would write a portion of the
existing header which is different in 'size' value. So we need to
prevent it and write a new pipe header along with other information
like event attributes and features.
This can handle something like this:
# perf record -a -B sleep 1
# perf inject -b -i perf.data | perf report -i -
Factor out perf_event__synthesize_for_pipe() to be shared between perf
record and inject.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210719223153.1618812-5-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf build fails on 5.12.0rc2 on s390 with this error message:
util/synthetic-events.c: In function
‘__event__synthesize_thread.part.0.isra’:
util/synthetic-events.c:787:19: error: ‘kernel_thread’ may be
used uninitialized in this function [-Werror=maybe-uninitialized]
787 | if (_pid == pid && !kernel_thread) {
| ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
The build succeeds using command 'make DEBUG=y'.
The variable kernel_thread is set by this function sequence:
__event__synthesize_thread()
| defines bool kernel_thread; as local variable and calls
+--> perf_event__prepare_comm(..., &kernel_thread)
+--> perf_event__get_comm_ids(..., bool *kernel);
On return of this function variable kernel is always
set to true or false.
To prevent this compile error, assign variable kernel_thread
a value when it is defined.
Output after:
[root@m35lp76 perf]# make util/synthetic-events.o
....
CC util/synthetic-events.o
[root@m35lp76 perf]#
Fixes: c1b907953b ("perf tools: Skip PERF_RECORD_MMAP event synthesis for kernel threads")
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Link: http://lore.kernel.org/lkml/20210309110447.834292-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
For X86, the var2_w field of PERF_SAMPLE_WEIGHT_STRUCT stands for the
instruction latency. Current perf forces the var2_w to the data->ins_lat
in the generic code. It works well for now because X86 is the only
architecture that supports the PERF_SAMPLE_WEIGHT_STRUCT, but it may
bring problems once other architectures support the sample type. For
example, the var2_w may be used to capture something else on PowerPC.
Create two architecture specific functions to parse and synthesize the
weight related samples. Move the X86 specific codes to the X86 version
functions. Other architectures can implement their own functions later
separately.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/1612540912-6562-1-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The instruction latency information can be recorded on some platforms,
e.g., the Intel Sapphire Rapids server. With both memory latency
(weight) and the new instruction latency information, users can easily
locate the expensive load instructions, and also understand the time
spent in different stages. The users can optimize their applications in
different pipeline stages.
The 'weight' field is shared among different architectures. Reusing the
'weight' field may impacts other architectures. Add a new field to store
the instruction latency.
Like the 'weight' support, introduce a 'ins_lat' for the global
instruction latency, and a 'local_ins_lat' for the local instruction
latency version.
Add new sort functions, INSTR Latency and Local INSTR Latency,
accordingly.
Add local_ins_lat to the default_mem_sort_order[].
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.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/1612296553-21962-7-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The new sample type, PERF_SAMPLE_WEIGHT_STRUCT, is an alternative of the
PERF_SAMPLE_WEIGHT sample type. Users can apply either the
PERF_SAMPLE_WEIGHT sample type or the PERF_SAMPLE_WEIGHT_STRUCT sample
type to retrieve the sample weight, but they cannot apply both sample
types simultaneously.
The new sample type shares the same space as the PERF_SAMPLE_WEIGHT
sample type. The lower 32 bits are exactly the same for both sample
type. The higher 32 bits may be different for different architecture.
Add arch specific arch_evsel__set_sample_weight() to set the new sample
type for X86. Only store the lower 32 bits for the sample->weight if the
new sample type is applied. In practice, no memory access could last
than 4G cycles. No data will be lost.
If the kernel doesn't support the new sample type. Fall back to the
PERF_SAMPLE_WEIGHT sample type.
There is no impact for other architectures.
Committer notes:
Fixup related to PERF_SAMPLE_CODE_PAGE_SIZE, present in acme/perf/core
but not upstream yet.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.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/1612296553-21962-6-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To synthesize information to resolve sample IPs, it needs to scan task
and mmap info from the /proc filesystem. For each process, it opens
(and reads) status and maps file respectively. But as kernel threads
don't have memory maps so we can skip the maps file.
To find kernel threads, check "VmPeak:" line in /proc/<PID>/status file.
It's about the peak virtual memory usage so only user-level tasks have
that. Note that it's possible to miss the line due to partial reads.
So we should double-check if it's a really kernel thread when there's no
VmPeak line.
Thus check "Threads:" line (which follows the VmPeak line whether or not
it exists) to be sure it's read enough data - just in case of deeply
nested pid namespaces or large number of supplementary groups are
involved.
This is for user process:
$ head -40 /proc/1/status
Name: systemd
Umask: 0000
State: S (sleeping)
Tgid: 1
Ngid: 0
Pid: 1
PPid: 0
TracerPid: 0
Uid: 0 0 0 0
Gid: 0 0 0 0
FDSize: 256
Groups:
NStgid: 1
NSpid: 1
NSpgid: 1
NSsid: 1
VmPeak: 234192 kB <-- here
VmSize: 169964 kB
VmLck: 0 kB
VmPin: 0 kB
VmHWM: 29528 kB
VmRSS: 6104 kB
RssAnon: 2756 kB
RssFile: 3348 kB
RssShmem: 0 kB
VmData: 19776 kB
VmStk: 1036 kB
VmExe: 784 kB
VmLib: 9532 kB
VmPTE: 116 kB
VmSwap: 2400 kB
HugetlbPages: 0 kB
CoreDumping: 0
THP_enabled: 1
Threads: 1 <-- and here
SigQ: 1/62808
SigPnd: 0000000000000000
ShdPnd: 0000000000000000
SigBlk: 7be3c0fe28014a03
SigIgn: 0000000000001000
And this is for kernel thread:
$ head -20 /proc/2/status
Name: kthreadd
Umask: 0000
State: S (sleeping)
Tgid: 2
Ngid: 0
Pid: 2
PPid: 0
TracerPid: 0
Uid: 0 0 0 0
Gid: 0 0 0 0
FDSize: 64
Groups:
NStgid: 2
NSpid: 2
NSpgid: 0
NSsid: 0
Threads: 1 <-- here
SigQ: 1/62808
SigPnd: 0000000000000000
ShdPnd: 0000000000000000
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@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/20210202090118.2008551-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To save memory usage, it needs to reduce the number of entries in the
proc filesystem. It's using /proc/<PID>/task directory to traverse
threads in the process and then kernel creates /proc/<PID>/task/<TID>
entries.
After that it checks the thread info using the /proc/<TID>/status file
rather than /proc/<PID>/task/<TID>/status. As far as I can see, they
are the same and contain all the info we need.
Using the latter eliminates the unnecessary /proc/<TID> entry. This can
be useful especially a large number of threads are used in the system.
In my experiment around 1KB of memory on average was saved for each
thread (which is not a thread group leader).
To do this, pass both pid and tid to perf_event_prepare_comm() if it
knows them. In case it doesn't know, passing 0 as pid will do the old
way.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@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/20210202090118.2008551-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
It didn't check the tool->cgroup_events bit which is set when the
--all-cgroups option is given. Without it, samples will not have cgroup
info so no reason to synthesize.
We can check the PERF_RECORD_CGROUP records after running perf record
*WITHOUT* the --all-cgroups option:
Before:
$ perf report -D | grep CGROUP
0 0 0x8430 [0x38]: PERF_RECORD_CGROUP cgroup: 1 /
CGROUP events: 1
CGROUP events: 0
CGROUP events: 0
After:
$ perf report -D | grep CGROUP
CGROUP events: 0
CGROUP events: 0
CGROUP events: 0
Committer testing:
Before:
# perf record -a sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 2.208 MB perf.data (10003 samples) ]
# perf report -D | grep "CGROUP events"
CGROUP events: 146
CGROUP events: 0
CGROUP events: 0
#
After:
# perf record -a sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 2.208 MB perf.data (10448 samples) ]
# perf report -D | grep "CGROUP events"
CGROUP events: 0
CGROUP events: 0
CGROUP events: 0
#
With all-cgroups:
# perf record --all-cgroups -a sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 2.374 MB perf.data (11526 samples) ]
# perf report -D | grep "CGROUP events"
CGROUP events: 146
CGROUP events: 0
CGROUP events: 0
#
Fixes: 8fb4b67939 ("perf record: Add --all-cgroups option")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201127054356.405481-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Replace build_id byte array with struct build_id object and all the code
that references it.
The objective is to carry size together with build id array, so it's
better to keep both together.
This is preparatory change for following patches, and there's no
functional change.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20201013192441.1299447-2-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
