After pmu_add_cpu_aliases() is called, perf_pmu__num_events() returns an
incorrect value that double counts common events and doesn't match the
actual count of events in the alias list. This is because after
'cpu_aliases_added == true', the number of events returned is
'sysfs_aliases + cpu_json_aliases'. But when adding 'case
EVENT_SRC_SYSFS' events, 'sysfs_aliases' and 'cpu_json_aliases' are both
incremented together, failing to account that these ones overlap and
only add a single item to the list. Fix it by adding another counter for
overlapping events which doesn't influence 'cpu_json_aliases'.
There doesn't seem to be a current issue because it's used in perf list
before pmu_add_cpu_aliases() so the correct value is returned. Other
uses in tests may also miss it for other reasons like only looking at
uncore events. However it's marked as a fixes commit in case any new fix
with new uses of perf_pmu__num_events() is backported.
Fixes: d9c5f5f94c ("perf pmu: Count sys and cpuid JSON events separately")
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Link: https://lore.kernel.org/r/20250226104111.564443-3-james.clark@linaro.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
In sysfs, the perf events are all located in
/sys/bus/event_source/devices/ but some places ended up hard-coding the
location to be at the root of /sys/devices/ which could be very risky as
you do not exactly know what type of device you are accessing in sysfs
at that location.
So fix this all up by properly pointing everything at the bus device
list instead of the root of the sysfs devices/ tree.
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Link: https://lore.kernel.org/r/2025021955-implant-excavator-179d@gregkh
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Wildcard PMU naming will match a name like pmu_1 to a PMU name like
pmu_10 but not to a PMU name like pmu_2 as the suffix forms part of
the match. No suffix matching will match pmu_10 to either pmu_1 or
pmu_2. Add or rename matching functions on PMU to make it clearer what
kind of matching is being performed.
Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Link: https://lore.kernel.org/r/20250201074320.746259-4-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Use the regular PMU approaches with tool json events to reduce the
amount of special tool_pmu code - tool_pmu__config_terms and
tool_pmu__for_each_event_cb are removed. Some functions remain, like
tool_pmu__str_to_event, as conveniences to metricgroups. Add
tool_pmu__skip_event/tool_pmu__num_skip_events to handle the case that
tool json events shouldn't appear on certain architectures. This isn't
done in jevents.py due to complexity in the empty-pmu-events.c and
when all vendor json is built into the tool.
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20241002032016.333748-10-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Add the expr literals like "#smt_on" as tool events, this allows stat
events to give the values. On my laptop with hyperthreading enabled:
```
$ perf stat -e "has_pmem,num_cores,num_cpus,num_cpus_online,num_dies,num_packages,smt_on,system_tsc_freq" true
Performance counter stats for 'true':
0 has_pmem
8 num_cores
16 num_cpus
16 num_cpus_online
1 num_dies
1 num_packages
1 smt_on
2,496,000,000 system_tsc_freq
0.001113637 seconds time elapsed
0.001218000 seconds user
0.000000000 seconds sys
```
And with hyperthreading disabled:
```
$ perf stat -e "has_pmem,num_cores,num_cpus,num_cpus_online,num_dies,num_packages,smt_on,system_tsc_freq" true
Performance counter stats for 'true':
0 has_pmem
8 num_cores
16 num_cpus
8 num_cpus_online
1 num_dies
1 num_packages
0 smt_on
2,496,000,000 system_tsc_freq
0.000802115 seconds time elapsed
0.000000000 seconds user
0.000806000 seconds sys
```
As zero matters for these values, in stat-display
should_skip_zero_counter only skip the zero value if it is not the
first aggregation index.
The tool event implementations are used in expr but not evaluated as
events for simplicity. Also core_wide isn't made a tool event as it
requires command line parameters.
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20241002032016.333748-8-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Rather than treat tool events as a special kind of event, create a
tool only PMU where the events/aliases match the existing
duration_time, user_time and system_time events. Remove special
parsing and printing support for the tool events, but add function
calls for when PMU functions are called on a tool_pmu.
Move the tool PMU code in evsel into tool_pmu.c to better encapsulate
the tool event behavior in that file.
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20241002032016.333748-5-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Hard coded terms like "config=10" are skipped by perf_pmu__config
assuming they were already applied to a perf_event_attr by parse
event's config_attr function. When doing a reverse number to name
lookup in perf_pmu__name_from_config, as the hardcoded terms aren't
applied the config value is incorrect leading to misses or false
matches. Fix this by adding a parameter to have perf_pmu__config apply
hardcoded terms too (not just in parse event's config_term_common).
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20241002032016.333748-3-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Arm PMUs have a suffix, either a single decimal (armv8_pmuv3_0) or 3 hex
digits which (armv8_cortex_a53) which Perf assumes are both strippable
suffixes for the purposes of deduplication. S390 "cpum_cf" is a
similarly suffixed core PMU but is only two characters so is not treated
as strippable because the rules are a minimum of 3 hex characters or 1
decimal character.
There are two paths involved in listing PMU events:
* HW/cache event printing assumes core PMUs don't have suffixes so
doesn't try to strip.
* Sysfs PMU events share the printing function with uncore PMUs which
strips.
This results in slightly inconsistent Perf list behavior if a core PMU
has a suffix:
# perf list
...
armv8_pmuv3_0/branch-load-misses/
armv8_pmuv3/l3d_cache_wb/ [Kernel PMU event]
...
Fix it by partially reverting back to the old list behavior where
stripping was only done for uncore PMUs. For example commit 8d9f5146f5
("perf pmus: Sort pmus by name then suffix") mentions that only PMUs
starting 'uncore_' are considered to have a potential suffix. This
change doesn't go back that far, but does only strip PMUs that are
!is_core. This keeps the desirable behavior where the many possibly
duplicated uncore PMUs aren't repeated, but it doesn't break listing for
core PMUs.
Searching for a PMU continues to use the new stripped comparison
functions, meaning that it's still possible to request an event by
specifying the common part of a PMU name, or even open events on
multiple similarly named PMUs. For example:
# perf stat -e armv8_cortex/inst_retired/
5777173628 armv8_cortex_a53/inst_retired/ (99.93%)
7469626951 armv8_cortex_a57/inst_retired/ (49.88%)
Fixes: 3241d46f5f ("perf pmus: Sort/merge/aggregate PMUs like mrvl_ddr_pmu")
Suggested-by: Ian Rogers <irogers@google.com>
Signed-off-by: James Clark <james.clark@arm.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: robin.murphy@arm.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240626145448.896746-3-james.clark@arm.com
Commit b2b9d3a3f0 ("perf pmu: Support wildcards on pmu name in dynamic
pmu events") gives the following example for wildcarding a subset of
PMUs:
E.g., in a system with the following dynamic pmus:
mypmu_0
mypmu_1
mypmu_2
mypmu_4
perf stat -e mypmu_[01]/<config>/
Since commit f91fa2ae63 ("perf pmu: Refactor perf_pmu__match()"), only
"*" has been supported, removing the ability to subset PMUs, even though
parse-events.l still supports ? and [] characters.
Fix it by using fnmatch() when any glob character is detected and add a
test which covers that and other scenarios of
perf_pmu__match_ignoring_suffix().
Fixes: f91fa2ae63 ("perf pmu: Refactor perf_pmu__match()")
Signed-off-by: James Clark <james.clark@arm.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: robin.murphy@arm.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240626145448.896746-2-james.clark@arm.com
The mrvl_ddr_pmu is uncore and has a hexadecimal address suffix while
the previous PMU sorting/merging code assumes uncore PMU names start
with uncore_ and have a decimal suffix. Because of the previous
assumption it isn't possible to wildcard the mrvl_ddr_pmu.
Modify pmu_name_len_no_suffix but also remove the suffix number out
argument, this is because we don't know if a suffix number of say 100
is in hexadecimal or decimal. As the only use of the suffix number is
in comparisons, it is safe there to compare the values as hexadecimal.
Modify perf_pmu__match_ignoring_suffix so that hexadecimal suffixes
are ignored.
Only allow hexadecimal suffixes to be greater than length 2 (ie 3 or
more) so that S390's cpum_cf PMU doesn't lose its suffix.
Change the return type of pmu_name_len_no_suffix to size_t to
workaround GCC incorrectly determining the result could be negative.
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: James Clark <james.clark@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Bharat Bhushan <bbhushan2@marvell.com>
Cc: Bhaskara Budiredla <bbudiredla@marvell.com>
Cc: Tuan Phan <tuanphan@os.amperecomputing.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240515060114.3268149-2-irogers@google.com
Perf event names aren't case sensitive. For sysfs events the entire
directory of events is read then iterated comparing names in a case
insensitive way, most often to see if an event is present.
Consider:
$ perf stat -e inst_retired.any true
The event inst_retired.any may be present in any PMU, so every PMU's
sysfs events are loaded and then searched with strcasecmp to see if
any match. This event is only present on the cpu PMU as a JSON event
so a lot of events were loaded from sysfs unnecessarily just to prove
an event didn't exist there.
This change avoids loading all the events by assuming sysfs event
names are always either lower or uppercase. It uses file exists and
only loads the events when the desired event is present.
For the example above, the number of openat calls measured by 'perf
trace' on a tigerlake laptop goes from 325 down to 255. The reduction
will be larger for machines with many PMUs, particularly replicated
uncore PMUs.
Ensure pmu_aliases_parse() is called before all uses of the aliases
list, but remove some "pmu->sysfs_aliases_loaded" tests as they are now
part of the function.
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jing Zhang <renyu.zj@linux.alibaba.com>
Cc: Jiri Olsa <jolsa@kernel.org>
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: Randy Dunlap <rdunlap@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Link: https://lore.kernel.org/r/20240502213507.2339733-7-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add perf_pmu__name_from_config that does a reverse lookup from a
config number to an alias name. The lookup is expensive as the config
is computed for every alias by filling in a perf_event_attr, but this
is only done when verbose output is enabled. The lookup also only
considers config, and not config1, config2 or config3.
An example of the output:
$ perf stat -vv -e data_read true
...
perf_event_attr:
type 24 (uncore_imc_free_running_0)
size 136
config 0x20ff (data_read)
sample_type IDENTIFIER
read_format TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
disabled 1
inherit 1
exclude_guest 1
...
Committer notes:
Fix the python binding build by adding dummies for not strictly
needed perf_pmu__name_from_config() and perf_pmus__find_by_type().
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.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: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.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: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Link: https://lore.kernel.org/r/20240308001915.4060155-7-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
A PMU event/alias will have a set of format terms that replace it when
an event is parsed. The location of the terms is their position when
parsed for the event/alias either from sysfs or json. This location is
of little use when an event fails to parse as the error will be given
in terms of the location in the string of events parsed not the json
or sysfs string. Fix this by making the cloned terms location that of
the event/alias.
If a cloned term from an event/alias is invalid the bad format is hard
to determine from the error string. Add the name of the bad format
into the error string.
Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: James Clark <james.clark@arm.com>
Cc: tchen168@asu.edu
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240131134940.593788-2-irogers@google.com
The msr PMU is a software one, meaning msr events may be grouped
with events in a hardware context. As the msr PMU isn't marked as a
software PMU by perf_pmu__is_software, groups with the msr PMU in
are broken and the msr events placed in a different group. This
may lead to multiplexing errors where a hardware event isn't
counted while the msr event, such as tsc, is. Fix all of this by
marking the msr PMU as software, which agrees with the driver.
Before:
```
$ perf stat -e '{slots,tsc}' -a true
WARNING: events were regrouped to match PMUs
Performance counter stats for 'system wide':
1,750,335 slots
4,243,557 tsc
0.001456717 seconds time elapsed
```
After:
```
$ perf stat -e '{slots,tsc}' -a true
Performance counter stats for 'system wide':
12,526,380 slots
3,415,163 tsc
0.001488360 seconds time elapsed
```
Fixes: 251aa04024 ("perf parse-events: Wildcard most "numeric" events")
Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Cc: James Clark <james.clark@arm.com>
Cc: Caleb Biggers <caleb.biggers@intel.com>
Cc: Edward Baker <edward.baker@intel.com>
Cc: Perry Taylor <perry.taylor@intel.com>
Cc: Samantha Alt <samantha.alt@intel.com>
Cc: Weilin Wang <weilin.wang@intel.com>
Link: https://lore.kernel.org/r/20240124234200.1510417-1-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
The perf tool has previously made legacy events the priority so with
or without a PMU the legacy event would be opened:
$ perf stat -e cpu-cycles,cpu/cpu-cycles/ true
Using CPUID GenuineIntel-6-8D-1
intel_pt default config: tsc,mtc,mtc_period=3,psb_period=3,pt,branch
Attempting to add event pmu 'cpu' with 'cpu-cycles,' that may result in non-fatal errors
After aliases, add event pmu 'cpu' with 'cpu-cycles,' that may result in non-fatal errors
Control descriptor is not initialized
------------------------------------------------------------
perf_event_attr:
type 0 (PERF_TYPE_HARDWARE)
size 136
config 0 (PERF_COUNT_HW_CPU_CYCLES)
sample_type IDENTIFIER
read_format TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
disabled 1
inherit 1
enable_on_exec 1
exclude_guest 1
------------------------------------------------------------
sys_perf_event_open: pid 833967 cpu -1 group_fd -1 flags 0x8 = 3
------------------------------------------------------------
perf_event_attr:
type 0 (PERF_TYPE_HARDWARE)
size 136
config 0 (PERF_COUNT_HW_CPU_CYCLES)
sample_type IDENTIFIER
read_format TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
disabled 1
inherit 1
enable_on_exec 1
exclude_guest 1
------------------------------------------------------------
...
Fixes to make hybrid/BIG.little PMUs behave correctly, ie as core PMUs
capable of opening legacy events on each, removing hard coded "cpu_core"
and "cpu_atom" Intel PMU names, etc. caused a behavioral difference on
Apple/ARM due to latent issues in the PMU driver reported in:
https://lore.kernel.org/lkml/08f1f185-e259-4014-9ca4-6411d5c1bc65@marcan.st/
As part of that report Mark Rutland <mark.rutland@arm.com> requested
that legacy events not be higher in priority when a PMU is specified
reversing what has until this change been perf's default behavior. With
this change the above becomes:
$ perf stat -e cpu-cycles,cpu/cpu-cycles/ true
Using CPUID GenuineIntel-6-8D-1
Attempt to add: cpu/cpu-cycles=0/
..after resolving event: cpu/event=0x3c/
Control descriptor is not initialized
------------------------------------------------------------
perf_event_attr:
type 0 (PERF_TYPE_HARDWARE)
size 136
config 0 (PERF_COUNT_HW_CPU_CYCLES)
sample_type IDENTIFIER
read_format TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
disabled 1
inherit 1
enable_on_exec 1
exclude_guest 1
------------------------------------------------------------
sys_perf_event_open: pid 827628 cpu -1 group_fd -1 flags 0x8 = 3
------------------------------------------------------------
perf_event_attr:
type 4 (PERF_TYPE_RAW)
size 136
config 0x3c
sample_type IDENTIFIER
read_format TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
disabled 1
inherit 1
enable_on_exec 1
exclude_guest 1
------------------------------------------------------------
...
So the second event has become a raw event as
/sys/devices/cpu/events/cpu-cycles exists.
A fix was necessary to config_term_pmu in parse-events.c as check_alias
expansion needs to happen after config_term_pmu, and config_term_pmu may
need calling a second time because of this.
config_term_pmu is updated to not use the legacy event when the PMU has
such a named event (either from JSON or sysfs).
The bulk of this change is updating all of the parse-events test
expectations so that if a sysfs/JSON event exists for a PMU the test
doesn't fail - a further sign, if it were needed, that the legacy event
priority was a known and tested behavior of the perf tool.
Reported-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Hector Martin <marcan@marcan.st>
Tested-by: Marc Zyngier <maz@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20231123042922.834425-1-irogers@google.com
[ Initialize the 'alias_rewrote_terms' variable to false to address a clang warning ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To get the latest fixes in the perf tools including perf stat output,
dlfilter and LLVM feature detection.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
The default config is computed during creation of the PMU and may do
things like scanning sysfs, when the PMU may just be used as part of
scanning. Change default_config to perf_event_attr_init_default, a
callback that is used when a default config needs initializing. This
avoids holding onto the memory for a perf_event_attr and copying.
On a tigerlake laptop running the pmu-scan benchmark:
Before:
Running 'internals/pmu-scan' benchmark:
Computing performance of sysfs PMU event scan for 100 times
Average core PMU scanning took: 28.780 usec (+- 0.503 usec)
Average PMU scanning took: 283.480 usec (+- 18.471 usec)
Number of openat syscalls: 30,227
After:
Running 'internals/pmu-scan' benchmark:
Computing performance of sysfs PMU event scan for 100 times
Average core PMU scanning took: 27.880 usec (+- 0.169 usec)
Average PMU scanning took: 245.260 usec (+- 15.758 usec)
Number of openat syscalls: 28,914
Over 3 runs it is a nearly 12% reduction in execution time and a 4.3%
of openat calls.
Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: James Clark <james.clark@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Will Deacon <will@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Jing Zhang <renyu.zj@linux.alibaba.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: John Garry <john.g.garry@oracle.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: coresight@lists.linaro.org
Link: https://lore.kernel.org/r/20231012175645.1849503-8-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
To pick up the 'perf bench sched-seccomp-notify' changes to allow us to
continue build testing perf-tools-next with the set of distro
containers, where some older ones don't have a recent enough seccomp.h
UAPI header that contains defines needed by this new 'perf bench'
workload.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
PMU alias names were computed when the first perf_pmu is created,
scanning all PMUs in event sources for a file called alias that
generally doesn't exist. Switch to trying to load the file when all
PMU related files are loaded in lookup. This would cause a PMU name
lookup of an alias name to fail if no PMUs were loaded, so in that
case all PMUs are loaded and the find repeated. The overhead is
similar but in the (very) general case not all PMUs are scanned for
the alias file.
As the overhead occurs once per invocation it doesn't show in perf
bench internals pmu-scan. On a tigerlake machine, the number of openat
system calls for an event of cpu/cycles/ with perf stat reduces from
94 to 69 (ie 25 fewer openat calls).
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: James Clark <james.clark@arm.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Link: https://lore.kernel.org/r/20230925062323.840799-1-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
The perf_pmu__parse_* functions for the sysfs files of pmu event’s
scale, unit, per-pkg and snapshot were updated in commit 7b723dbb96
("perf pmu: Be lazy about loading event info files from sysfs").
However, the paths for these sysfs files were incorrect. This resulted
in perf stat reporting values with wrong scaling and missing units. This
is fixed by correcting the paths for these sysfs files.
Before this fix:
$sudo perf stat -e power/energy-pkg/ -- sleep 2
Performance counter stats for 'system wide':
351,217,188,864 power/energy-pkg/
2.004127961 seconds time elapsed
After this fix:
$sudo perf stat -e power/energy-pkg/ -- sleep 2
Performance counter stats for 'system wide':
80.58 Joules power/energy-pkg/
2.004009749 seconds time elapsed
Fixes: 7b723dbb96 ("perf pmu: Be lazy about loading event info files from sysfs")
Signed-off-by: Wyes Karny <wyes.karny@amd.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: ravi.bangoria@amd.com
Cc: sandipan.das@amd.com
Cc: james.clark@arm.com
Cc: kan.liang@linux.intel.com
Link: https://lore.kernel.org/r/20230920122349.418673-1-wyes.karny@amd.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Fix an error detected by memory sanitizer:
```
==4033==WARNING: MemorySanitizer: use-of-uninitialized-value
#0 0x55fb0fbedfc7 in read_alias_info tools/perf/util/pmu.c:457:6
#1 0x55fb0fbea339 in check_info_data tools/perf/util/pmu.c:1434:2
#2 0x55fb0fbea339 in perf_pmu__check_alias tools/perf/util/pmu.c:1504:9
#3 0x55fb0fbdca85 in parse_events_add_pmu tools/perf/util/parse-events.c:1429:32
#4 0x55fb0f965230 in parse_events_parse tools/perf/util/parse-events.y:299:6
#5 0x55fb0fbdf6b2 in parse_events__scanner tools/perf/util/parse-events.c:1822:8
#6 0x55fb0fbdf8c1 in __parse_events tools/perf/util/parse-events.c:2094:8
#7 0x55fb0fa8ffa9 in parse_events tools/perf/util/parse-events.h:41:9
#8 0x55fb0fa8ffa9 in test_event tools/perf/tests/parse-events.c:2393:8
#9 0x55fb0fa8f458 in test__pmu_events tools/perf/tests/parse-events.c:2551:15
#10 0x55fb0fa6d93f in run_test tools/perf/tests/builtin-test.c:242:9
#11 0x55fb0fa6d93f in test_and_print tools/perf/tests/builtin-test.c:271:8
#12 0x55fb0fa6d082 in __cmd_test tools/perf/tests/builtin-test.c:442:5
#13 0x55fb0fa6d082 in cmd_test tools/perf/tests/builtin-test.c:564:9
#14 0x55fb0f942720 in run_builtin tools/perf/perf.c:322:11
#15 0x55fb0f942486 in handle_internal_command tools/perf/perf.c:375:8
#16 0x55fb0f941dab in run_argv tools/perf/perf.c:419:2
#17 0x55fb0f941dab in main tools/perf/perf.c:535:3
```
Fixes: 7b723dbb96 ("perf pmu: Be lazy about loading event info files from sysfs")
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@arm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Link: https://lore.kernel.org/r/20230914022425.1489035-1-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
