The 'Session topology' test currently fails with this message when
evlist__new_default() opens more than one event:
32: Session topology :
--- start ---
templ file: /tmp/perf-test-vv5YzZ
Using CPUID 0x00000000410fd070
Opening: unknown-hardware:HG
------------------------------------------------------------
perf_event_attr:
type 0 (PERF_TYPE_HARDWARE)
config 0xb00000000
disabled 1
------------------------------------------------------------
sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 = 4
Opening: unknown-hardware:HG
------------------------------------------------------------
perf_event_attr:
type 0 (PERF_TYPE_HARDWARE)
config 0xa00000000
disabled 1
------------------------------------------------------------
sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 = 5
non matching sample_type
FAILED tests/topology.c:73 can't get session
---- end ----
Session topology: FAILED!
This is because when re-opening the file and parsing the header, Perf
expects that any file that has more than one event has the sample ID
flag set. Perf record already sets the flag in a similar way when there
is more than one event, so add the same logic to evlist__new_default().
evlist__new_default() is only currently used in tests, so I don't
expect this change to have any other side effects. The other tests that
use it don't save and re-open the file so don't hit this issue.
The session topology test has been failing on Arm big.LITTLE platforms
since commit 251aa04024 ("perf parse-events: Wildcard most
"numeric" events") when evlist__new_default() started opening multiple
events for 'cycles'.
Fixes: 251aa04024 ("perf parse-events: Wildcard most "numeric" events")
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: James Clark <james.clark@arm.com>
[ This was failing as well on a Rocket Lake Refresh/14700k Intel hybrid system - Arnaldo ]
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Ian Rogers <irogers@google.com>
Tested-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Changbin Du <changbin.du@huawei.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>
Cc: Yang Jihong <yangjihong1@huawei.com>
Closes: https://lore.kernel.org/lkml/CAP-5=fWVQ-7ijjK3-w1q+k2WYVNHbAcejb-xY0ptbjRw476VKA@mail.gmail.com/
Link: https://lore.kernel.org/r/20240124094358.489372-1-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When turning an event with attributes to the format including the PMU we
need to move the "event:attributes" format to "event/attributes/" so
that we can copy the event displayed and use it in the command line,
i.e. in 'perf top' we had:
1K cpu_atom/cycles:P/
11K cpu_core/cycles:P/
If I try to use that on the command line:
# perf top -e cpu_atom/cycles:P/
event syntax error: 'cpu_atom/cycles:P/'
\___ Bad event or PMU
Unable to find PMU or event on a PMU of 'cpu_atom'
Initial error:
event syntax error: 'cpu_atom/cycles:P/'
\___ unknown term 'cycles:P' for pmu
'cpu_atom'
valid terms:
event,pc,edge,offcore_rsp,ldlat,inv,umask,cmask,config,config1,config2,config3,name,period,freq,branch_type,time,call-graph,stack-size,no-inherit,inherit,max-stack,nr,no-overwrite,overwrite ,driver-config,percore,aux-output,aux-sample-size,metric-id,raw,legacy-cache,hardware
Run
'perf list' for a list of valid events
Usage: perf top [<options>]
-e, --event <event> event selector. use 'perf list' to list available events
#
Tested-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Hector Martin <marcan@marcan.st>
Cc: Ian Rogers <irogers@google.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/ZXxyanyZgWBTOnoK@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
It's hard to distinguish the default cycles events among hybrid PMUs.
For example,
$ perf top
Available samples
385 cycles:P
903 cycles:P
The other tool, e.g., perf record, uniforms the event name and adds the
hybrid PMU name before opening the event. So the events can be easily
distinguished. Apply the same methodology for the perf top as well.
The evlist__uniquify_name() will be invoked by both record and top.
Move it to util/evlist.c
With the patch:
$ perf top
Available samples
148 cpu_atom/cycles:P/
1K cpu_core/cycles:P/
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Hector Martin <marcan@marcan.st>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20231214144612.1092028-2-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Dummy events are created with an attribute where the period and freq
are zero. evsel__config will then see the uninitialized values and
initialize them in evsel__default_freq_period. As fequency mode is
used by default the dummy event would be set to use frequency
mode. However, this has no effect on the dummy event but does cause
unnecessary timers/interrupts. Avoid this overhead by setting the
period to 1 for dummy events.
evlist__add_aux_dummy calls evlist__add_dummy then sets freq=0 and
period=1. This isn't necessary after this change and so the setting is
removed.
From Stephane:
The dummy event is not counting anything. It is used to collect mmap
records and avoid a race condition during the synthesize mmap phase of
perf record. As such, it should not cause any overhead during active
profiling. Yet, it did. Because of a bug the dummy event was
programmed as a sampling event in frequency mode. Events in that mode
incur more kernel overheads because on timer tick, the kernel has to
look at the number of samples for each event and potentially adjust
the sampling period to achieve the desired frequency. The dummy event
was therefore adding a frequency event to task and ctx contexts we may
otherwise not have any, e.g.,
perf record -a -e cpu/event=0x3c,period=10000000/.
On each timer tick the perf_adjust_freq_unthr_context() is invoked and
if ctx->nr_freq is non-zero, then the kernel will loop over ALL the
events of the context looking for frequency mode ones. In doing, so it
locks the context, and enable/disable the PMU of each hw event. If all
the events of the context are in period mode, the kernel will have to
traverse the list for nothing incurring overhead. The overhead is
multiplied by a very large factor when this happens in a guest kernel.
There is no need for the dummy event to be in frequency mode, it does
not count anything and therefore should not cause extra overhead for
no reason.
Fixes: 5bae025023 ("perf evlist: Introduce perf_evlist__new_dummy constructor")
Reported-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Link: https://lore.kernel.org/r/20230916035640.1074422-1-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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>
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>
Needed to get the event_attr_init() and perf_event_paranoid() prototypes
that were being obtained indirectly, by sheer luck.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Some places were including event.h just to get 'struct perf_sample',
move it to a separate place so that we speed up a bit the build.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
AUX area traces can produce too much data to record successfully or
analyze subsequently. Add another means to reduce data collection by
allowing multiple recording time ranges.
This is useful, for instance, in cases where a workload produces
predictably reproducible events in specific time ranges.
Today we only have perf record -D <msecs> to start at a specific region, or
some complicated approach using snapshot mode and external scripts sending
signals or using the fifos. But these approaches are difficult to set up
compared with simply having perf do it.
Extend perf record option -D/--delay option to specifying relative time
stamps for start stop controlled by perf with the right time offset, for
instance:
perf record -e intel_pt// -D 10-20,30-40
to record 10ms to 20ms into the trace and 30ms to 40ms.
Example:
The example workload is:
$ cat repeat-usleep.c
int usleep(useconds_t usec);
int usage(int ret, const char *msg)
{
if (msg)
fprintf(stderr, "%s\n", msg);
fprintf(stderr, "Usage is: repeat-usleep <microseconds>\n");
return ret;
}
int main(int argc, char *argv[])
{
unsigned long usecs;
char *end_ptr;
if (argc != 2)
return usage(1, "Error: Wrong number of arguments!");
errno = 0;
usecs = strtoul(argv[1], &end_ptr, 0);
if (errno || *end_ptr || usecs > UINT_MAX)
return usage(1, "Error: Invalid argument!");
while (1) {
int ret = usleep(usecs);
if (ret & errno != EINTR)
return usage(1, "Error: usleep() failed!");
}
return 0;
}
$ perf record -e intel_pt//u --delay 10-20,40-70,110-160 -- ./repeat-usleep 500
Events disabled
Events enabled
Events disabled
Events enabled
Events disabled
Events enabled
Events disabled
[ perf record: Woken up 5 times to write data ]
[ perf record: Captured and wrote 0.204 MB perf.data ]
Terminated
A dlfilter is used to determine continuous data collection (timestamps
less than 1ms apart):
$ cat dlfilter-show-delays.c
static __u64 start_time;
static __u64 last_time;
int start(void **data, void *ctx)
{
printf("%-17s\t%-9s\t%-6s\n", " Time", " Duration", " Delay");
return 0;
}
int filter_event_early(void *data, const struct perf_dlfilter_sample *sample, void *ctx)
{
__u64 delta;
if (!sample->time)
return 1;
if (!last_time)
goto out;
delta = sample->time - last_time;
if (delta < 1000000)
goto out2;;
printf("%17.9f\t%9.1f\t%6.1f\n", start_time / 1000000000.0, (last_time - start_time) / 1000000.0, delta / 1000000.0);
out:
start_time = sample->time;
out2:
last_time = sample->time;
return 1;
}
int stop(void *data, void *ctx)
{
printf("%17.9f\t%9.1f\n", start_time / 1000000000.0, (last_time - start_time) / 1000000.0);
return 0;
}
The result shows the times roughly match the --delay option:
$ perf script --itrace=qb --dlfilter dlfilter-show-delays.so
Time Duration Delay
39215.302317300 9.7 20.5
39215.332480217 30.4 40.9
39215.403837717 49.8
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Bayduraev <alexey.v.bayduraev@linux.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>
Link: https://lore.kernel.org/r/20220824072814.16422-6-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Current perf stat uses the evlist__add_default_attrs() to add the
generic default attrs, and uses arch_evlist__add_default_attrs() to add
the Arch specific default attrs, e.g., Topdown for x86.
It works well for the non-hybrid platforms. However, for a hybrid
platform, the hard code generic default attrs don't work.
Uses arch_evlist__add_default_attrs() to replace the
evlist__add_default_attrs(). The arch_evlist__add_default_attrs() is
modified to invoke the same __evlist__add_default_attrs() for the
generic default attrs. No functional change.
Add default_null_attrs[] to indicate the arch specific attrs.
No functional change for the arch specific default attrs either.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220721065706.2886112-4-zhengjun.xing@linux.intel.com
Signed-off-by: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When parsing a sample with a sample ID, copy machine_pid and vcpu from
perf_sample_id to perf_sample.
Note, machine_pid will be zero when unused, so only a non-zero value
represents a guest machine. vcpu should be ignored if machine_pid is zero.
Note also, machine_pid is used with events that have come from injecting a
guest perf.data file, however guest events recorded on the host (i.e. using
perf kvm) have the (QEMU) hypervisor process pid to identify them - refer
machines__find_for_cpumode().
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: kvm@vger.kernel.org
Link: https://lore.kernel.org/r/20220711093218.10967-14-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
If any member in a group has a different cpu mask than the other
members, the current perf stat disables group. when the perf metrics
topdown events are part of the group, the below <not supported> error
will be triggered.
$ perf stat -e "{slots,topdown-retiring,uncore_imc_free_running_0/dclk/}" -a sleep 1
WARNING: grouped events cpus do not match, disabling group:
anon group { slots, topdown-retiring, uncore_imc_free_running_0/dclk/ }
Performance counter stats for 'system wide':
141,465,174 slots
<not supported> topdown-retiring
1,605,330,334 uncore_imc_free_running_0/dclk/
The perf metrics topdown events must always be grouped with a slots
event as leader.
Factor out evsel__remove_from_group() to only remove the regular events
from the group.
Remove evsel__must_be_in_group(), since no one use it anymore.
With the patch, the topdown events aren't broken from the group for the
splitting.
$ perf stat -e "{slots,topdown-retiring,uncore_imc_free_running_0/dclk/}" -a sleep 1
WARNING: grouped events cpus do not match, disabling group:
anon group { slots, topdown-retiring, uncore_imc_free_running_0/dclk/ }
Performance counter stats for 'system wide':
346,110,588 slots
124,608,256 topdown-retiring
1,606,869,976 uncore_imc_free_running_0/dclk/
1.003877592 seconds time elapsed
Fixes: a9a1790247 ("perf stat: Ensure group is defined on top of the same cpu mask")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20220518143900.1493980-3-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When the target is a pid, not started by 'perf stat' we need to disable
the events, and in that case there is no need to setup affinities as we
use a dummy CPU map, with just one entry set to -1.
So stop doing it to avoid this needless call to sched_getaffinity():
# strace -ke sched_getaffinity perf stat -e cycles -p 241957 sleep 1
<SNIP>
sched_getaffinity(0, 512, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31]) = 8
> /usr/lib64/libc-2.33.so(sched_getaffinity@@GLIBC_2.3.4+0x1a) [0xe6eea]
> /var/home/acme/bin/perf(affinity__setup+0x6a) [0x532a2a]
> /var/home/acme/bin/perf(__evlist__disable.constprop.0+0x27) [0x4b9827]
> /var/home/acme/bin/perf(cmd_stat+0x29b5) [0x431725]
> /var/home/acme/bin/perf(run_builtin+0x6a) [0x4a2cfa]
> /var/home/acme/bin/perf(main+0x612) [0x40f8c2]
> /usr/lib64/libc-2.33.so(__libc_start_main+0xd4) [0x27b74]
> /var/home/acme/bin/perf(_start+0x2d) [0x40fadd]
<SNIP>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20220117160931.1191712-5-acme@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When the target is a pid, not started by 'perf stat' we need to enable
the events, and in that case there is no need to setup affinities as we
use a dummy CPU map, with just one entry set to -1.
So stop doing it to avoid this needless call to sched_getaffinity():
# strace -ke sched_getaffinity perf stat -e cycles -p 241957 sleep 1
<SNIP>
sched_getaffinity(0, 512, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31]) = 8
> /usr/lib64/libc-2.33.so(sched_getaffinity@@GLIBC_2.3.4+0x1a) [0xe6eea]
> /var/home/acme/bin/perf(affinity__setup+0x6a) [0x5329ca]
> /var/home/acme/bin/perf(__evlist__enable.constprop.0+0x23) [0x4b9693]
> /var/home/acme/bin/perf(enable_counters+0x14d) [0x42de5d]
> /var/home/acme/bin/perf(cmd_stat+0x2358) [0x4310c8]
> /var/home/acme/bin/perf(run_builtin+0x6a) [0x4a2cfa]
> /var/home/acme/bin/perf(main+0x612) [0x40f8c2]
> /usr/lib64/libc-2.33.so(__libc_start_main+0xd4) [0x27b74]
> /var/home/acme/bin/perf(_start+0x2d) [0x40fadd]
<SNIP>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20220117160931.1191712-4-acme@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
