Currently, `perf stat` skips or hides metrics when the underlying
hardware events cannot be counted (e.g., due to insufficient permissions
or unsupported events).
In `--metric-only` mode, this often results in missing columns or blank
spaces, making the output difficult to parse.
Modify the logic to ensure metrics are consistently displayed by
propagating NAN (Not a Number) through the expression evaluator.
Specifically:
1. Update `prepare_metric()` in stat-shadow.c to treat uncounted events
(where `run == 0`) as NAN. This leverages the existing math in expr.y
to propagate NAN through metric expressions.
2. Remove the early return in the display logic's `printout()` function
that was previously skipping metrics in `--metric-only` mode for
failed events.
l
3. Simplify `perf_stat__skip_metric_event()` to no longer depend on
event runtime.
Tested:
1. `perf all metrics test` did not crash while paranoid is 2.
2. Multiple combinations with `CPUs_utilized` while paranoid is 2.
$ ./perf stat -M CPUs_utilized -a -- sleep 1
Performance counter stats for 'system wide':
<not supported> msec cpu-clock:u # nan CPUs CPUs_utilized
1,006,356,120 duration_time
1.004375550 seconds time elapsed
$ ./perf stat -M CPUs_utilized -a -j -- sleep 1
{"counter-value" : "<not supported>", "unit" : "msec", "event" : "cpu-clock:u", "event-runtime" : 0, "pcnt-running" : 100.00, "metric-value" : "nan", "metric-unit" : "CPUs CPUs_utilized"}
{"counter-value" : "1006642462.000000", "unit" : "", "event" : "duration_time", "event-runtime" : 1, "pcnt-running" : 100.00}
$ ./perf stat -M CPUs_utilized -a --metric-only -- sleep 1
Performance counter stats for 'system wide':
CPUs CPUs_utilized
nan
1.004424652 seconds time elapsed
$ ./perf stat -M CPUs_utilized -a --metric-only -j -- sleep 1
{"CPUs CPUs_utilized" : "none"}
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Chun-Tse Shao <ctshao@google.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@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
walltime_nsecs_stats is no longer used for counter values, move into
that stat_config where it controls certain things like noise
measurement.
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
The ru_stats are used to capture user and system time stats when a
process exits. These are then applied to user and system time tool
events if their reads fail due to the process terminating. Reduce the
scope now the metric code no longer reads these values.
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
When reading time values for metrics don't use the globals updated in
builtin-stat, just read the events as regular events. The only
exception is for time events where nanoseconds need converting to
seconds as metrics assume time metrics are in seconds.
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
errno.h isn't used in auxtrace.h so remove it and fix build failures
caused by transitive dependencies through auxtrace.h on errno.h.
Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
For the sake of better documentation, add core_wide and target_cpu to
the tool.json. When the values of system_wide and
user_requested_cpu_list are unknown, use the values from the global
stat_config.
Example output showing how '-a' modifies the values in `perf stat`:
```
$ perf stat -e core_wide,target_cpu true
Performance counter stats for 'true':
0 core_wide
0 target_cpu
0.000993787 seconds time elapsed
0.001128000 seconds user
0.000000000 seconds sys
$ perf stat -e core_wide,target_cpu -a true
Performance counter stats for 'system wide':
1 core_wide
1 target_cpu
0.002271723 seconds time elapsed
$ perf list
...
tool:
core_wide
[1 if not SMT,if SMT are events being gathered on all SMT threads 1 otherwise 0. Unit: tool]
...
target_cpu
[1 if CPUs being analyzed,0 if threads/processes. Unit: tool]
...
```
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
The logic to skip output of a default metric line was firing on
Alderlake and not displaying 'TopdownL1 (cpu_atom)'. Remove the
need_full_name check as it is equivalent to the different PMU test in
the cases we care about, merge the 'if's and flip the evsel of the PMU
test. The 'if' is now basically saying, if the output matches the last
printed output then skip the output.
Before:
```
TopdownL1 (cpu_core) # 11.3 % tma_bad_speculation
# 24.3 % tma_frontend_bound
TopdownL1 (cpu_core) # 33.9 % tma_backend_bound
# 30.6 % tma_retiring
# 42.2 % tma_backend_bound
# 25.0 % tma_frontend_bound (49.81%)
# 12.8 % tma_bad_speculation
# 20.0 % tma_retiring (59.46%)
```
After:
```
TopdownL1 (cpu_core) # 8.3 % tma_bad_speculation
# 43.7 % tma_frontend_bound
# 30.7 % tma_backend_bound
# 17.2 % tma_retiring
TopdownL1 (cpu_atom) # 31.9 % tma_backend_bound
# 37.6 % tma_frontend_bound (49.66%)
# 18.0 % tma_bad_speculation
# 12.6 % tma_retiring (59.58%)
```
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Now that the metrics are encoded in common json the hard coded
printing means the metrics are shown twice. Remove the hard coded
version.
This means that when specifying events, and those events correspond to
a hard coded metric, the metric will no longer be displayed. The
metric will be displayed if the metric is requested. Due to the adhoc
printing in the previous approach it was often found frustrating, the
new approach avoids this.
The default perf stat output on an alderlake now looks like:
```
$ perf stat -a -- sleep 1
Performance counter stats for 'system wide':
19,697 context-switches # nan cs/sec cs_per_second
TopdownL1 (cpu_core) # 10.7 % tma_bad_speculation
# 24.9 % tma_frontend_bound
TopdownL1 (cpu_core) # 34.3 % tma_backend_bound
# 30.1 % tma_retiring
6,593 page-faults # nan faults/sec page_faults_per_second
729,065,658 cpu_atom/cpu-cycles/ # nan GHz cycles_frequency (49.79%)
1,605,131,101 cpu_core/cpu-cycles/ # nan GHz cycles_frequency
# 19.7 % tma_bad_speculation
# 14.2 % tma_retiring (50.14%)
# 37.3 % tma_frontend_bound (50.31%)
87,302,268 cpu_atom/branches/ # nan M/sec branch_frequency (60.27%)
512,046,956 cpu_core/branches/ # nan M/sec branch_frequency
1,111 cpu-migrations # nan migrations/sec migrations_per_second
# 28.8 % tma_backend_bound (60.26%)
0.00 msec cpu-clock # 0.0 CPUs CPUs_utilized
392,509,323 cpu_atom/instructions/ # 0.6 instructions insn_per_cycle (60.19%)
2,990,369,310 cpu_core/instructions/ # 1.9 instructions insn_per_cycle
3,493,478 cpu_atom/branch-misses/ # 5.9 % branch_miss_rate (49.69%)
7,297,531 cpu_core/branch-misses/ # 1.4 % branch_miss_rate
1.006621701 seconds time elapsed
```
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Some Default group metrics require their events showing for
consistency with perf's previous behavior. Add a flag to indicate when
this is the case and use it in stat-display.
As events are coming from Default metrics remove that default hardware
and software events from perf stat.
Following this change the default perf stat output on an alderlake looks like:
```
$ perf stat -a -- sleep 1
Performance counter stats for 'system wide':
20,550 context-switches # nan cs/sec cs_per_second
TopdownL1 (cpu_core) # 9.0 % tma_bad_speculation
# 28.1 % tma_frontend_bound
TopdownL1 (cpu_core) # 29.2 % tma_backend_bound
# 33.7 % tma_retiring
6,685 page-faults # nan faults/sec page_faults_per_second
790,091,064 cpu_atom/cpu-cycles/
# nan GHz cycles_frequency (49.83%)
2,563,918,366 cpu_core/cpu-cycles/
# nan GHz cycles_frequency
# 12.3 % tma_bad_speculation
# 14.5 % tma_retiring (50.20%)
# 33.8 % tma_frontend_bound (50.24%)
76,390,322 cpu_atom/branches/ # nan M/sec branch_frequency (60.20%)
1,015,173,047 cpu_core/branches/ # nan M/sec branch_frequency
1,325 cpu-migrations # nan migrations/sec migrations_per_second
# 39.3 % tma_backend_bound (60.17%)
0.00 msec cpu-clock # 0.000 CPUs utilized
# 0.0 CPUs CPUs_utilized
554,347,072 cpu_atom/instructions/ # 0.64 insn per cycle
# 0.6 instructions insn_per_cycle (60.14%)
5,228,931,991 cpu_core/instructions/ # 2.04 insn per cycle
# 2.0 instructions insn_per_cycle
4,308,874 cpu_atom/branch-misses/ # 5.65% of all branches
# 5.6 % branch_miss_rate (49.76%)
9,890,606 cpu_core/branch-misses/ # 0.97% of all branches
# 1.0 % branch_miss_rate
1.005477803 seconds time elapsed
```
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
The rblist of metric_event that then have a list of associated
metric_expr is moved out of the stat_config and into the evlist. This
is done as part of refactoring things for python, having the state
split in two places complicates that implementation. The evlist is
doing the harder work of enabling and disabling events, the metrics
are needed to compute a value and it doesn't seem unreasonable to hang
them from the evlist.
Signed-off-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250710235126.1086011-7-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Legacy events typically don't have a PMU when added leading to
mismatched legacy/non-legacy cases in find_stat. Use evsel__find_pmu
to make sure the evsel PMU is looked up. Update the evsel__find_pmu
code to look for the PMU using the extended config type or, for legacy
hardware/hw_cache events on non-hybrid systems, just use the core PMU.
Before:
```
$ perf stat -e cycles,cpu/instructions/ -a sleep 1
Performance counter stats for 'system wide':
215,309,764 cycles
44,326,491 cpu/instructions/
1.002555314 seconds time elapsed
```
After:
```
$ perf stat -e cycles,cpu/instructions/ -a sleep 1
Performance counter stats for 'system wide':
990,676,332 cycles
1,235,762,487 cpu/instructions/ # 1.25 insn per cycle
1.002667198 seconds time elapsed
```
Fixes: 3612ca8e29 ("perf stat: Fix the hard-coded metrics calculation on the hybrid")
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Tested-by: Leo Yan <leo.yan@arm.com>
Tested-by: Atish Patra <atishp@rivosinc.com>
Link: https://lore.kernel.org/r/20250109222109.567031-3-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>
The hard-coded metrics is wrongly calculated on the hybrid machine.
$ perf stat -e cycles,instructions -a sleep 1
Performance counter stats for 'system wide':
18,205,487 cpu_atom/cycles/
9,733,603 cpu_core/cycles/
9,423,111 cpu_atom/instructions/ # 0.52 insn per cycle
4,268,965 cpu_core/instructions/ # 0.23 insn per cycle
The insn per cycle for cpu_core should be 4,268,965 / 9,733,603 = 0.44.
When finding the metric events, the find_stat() doesn't take the PMU
type into account. The cpu_atom/cycles/ is wrongly used to calculate
the IPC of the cpu_core.
In the hard-coded metrics, the events from a different PMU are only
SW_CPU_CLOCK and SW_TASK_CLOCK. They both have the stat type,
STAT_NSECS. Except the SW CLOCK events, check the PMU type as well.
Fixes: 0a57b91080 ("perf stat: Use counts rather than saved_value")
Reported-by: Khalil, Amiri <amiri.khalil@intel.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240606180316.4122904-1-kan.liang@linux.intel.com
In the default mode, the current output of the metricgroup include both
events and metrics, which is not necessary and just makes the output
hard to read. Since different ARCHs (even different generations in the
same ARCH) may use different events. The output also vary on different
platforms.
For a metricgroup, only outputting the value of each metric is good
enough.
Add a new field default_metricgroup in evsel to indicate an event of the
default metricgroup. For those events, printout() should print the
metricgroup name rather than each event.
Add perf_stat__skip_metric_event() to skip the evsel in the Default
metricgroup, if it's not running or not the metric event.
Add print_metricgroup_header_t to pass the functions which print the
display name of each metricgroup in the Default metricgroup. Support all
three output methods.
Factor out perf_stat__print_shadow_stats_metricgroup() to print out each
metrics.
On SPR:
Before:
./perf_old stat sleep 1
Performance counter stats for 'sleep 1':
0.54 msec task-clock:u # 0.001 CPUs utilized
0 context-switches:u # 0.000 /sec
0 cpu-migrations:u # 0.000 /sec
68 page-faults:u # 125.445 K/sec
540,970 cycles:u # 0.998 GHz
556,325 instructions:u # 1.03 insn per cycle
123,602 branches:u # 228.018 M/sec
6,889 branch-misses:u # 5.57% of all branches
3,245,820 TOPDOWN.SLOTS:u # 18.4 % tma_backend_bound
# 17.2 % tma_retiring
# 23.1 % tma_bad_speculation
# 41.4 % tma_frontend_bound
564,859 topdown-retiring:u
1,370,999 topdown-fe-bound:u
603,271 topdown-be-bound:u
744,874 topdown-bad-spec:u
12,661 INT_MISC.UOP_DROPPING:u # 23.357 M/sec
1.001798215 seconds time elapsed
0.000193000 seconds user
0.001700000 seconds sys
After:
$ ./perf stat sleep 1
Performance counter stats for 'sleep 1':
0.51 msec task-clock:u # 0.001 CPUs utilized
0 context-switches:u # 0.000 /sec
0 cpu-migrations:u # 0.000 /sec
68 page-faults:u # 132.683 K/sec
545,228 cycles:u # 1.064 GHz
555,509 instructions:u # 1.02 insn per cycle
123,574 branches:u # 241.120 M/sec
6,957 branch-misses:u # 5.63% of all branches
TopdownL1 # 17.5 % tma_backend_bound
# 22.6 % tma_bad_speculation
# 42.7 % tma_frontend_bound
# 17.1 % tma_retiring
TopdownL2 # 21.8 % tma_branch_mispredicts
# 11.5 % tma_core_bound
# 13.4 % tma_fetch_bandwidth
# 29.3 % tma_fetch_latency
# 2.7 % tma_heavy_operations
# 14.5 % tma_light_operations
# 0.8 % tma_machine_clears
# 6.1 % tma_memory_bound
1.001712086 seconds time elapsed
0.000151000 seconds user
0.001618000 seconds sys
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ahmad Yasin <ahmad.yasin@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20230616031420.3751973-3-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Division by zero causes expression parsing to fail and no metric to be
generated. This can mean for short running benchmarks metrics are not
shown. Change the behavior to make the value nan, which gets shown like:
'''
$ perf stat -M TopdownL2 true
Performance counter stats for 'true':
1,031,492 INST_RETIRED.ANY # nan % tma_fetch_bandwidth
# nan % tma_heavy_operations
# nan % tma_light_operations
29,304 CPU_CLK_UNHALTED.REF_XCLK # nan % tma_fetch_latency
# nan % tma_branch_mispredicts
# nan % tma_machine_clears
# nan % tma_core_bound
# nan % tma_memory_bound
2,658,319 IDQ_UOPS_NOT_DELIVERED.CORE
11,167 EXE_ACTIVITY.BOUND_ON_STORES
262,058 EXE_ACTIVITY.1_PORTS_UTIL
<not counted> BR_MISP_RETIRED.ALL_BRANCHES (0.00%)
<not counted> INT_MISC.RECOVERY_CYCLES_ANY (0.00%)
<not counted> CPU_CLK_UNHALTED.ONE_THREAD_ACTIVE (0.00%)
<not counted> CPU_CLK_UNHALTED.THREAD (0.00%)
<not counted> UOPS_RETIRED.RETIRE_SLOTS (0.00%)
<not counted> CYCLE_ACTIVITY.STALLS_MEM_ANY (0.00%)
<not counted> UOPS_RETIRED.MACRO_FUSED (0.00%)
<not counted> IDQ_UOPS_NOT_DELIVERED.CYCLES_0_UOPS_DELIV.CORE (0.00%)
<not counted> EXE_ACTIVITY.2_PORTS_UTIL (0.00%)
<not counted> CYCLE_ACTIVITY.STALLS_TOTAL (0.00%)
<not counted> MACHINE_CLEARS.COUNT (0.00%)
<not counted> UOPS_ISSUED.ANY (0.00%)
0.002864879 seconds time elapsed
0.003012000 seconds user
0.000000000 seconds sys
'''
When events aren't supported a count of 0 can be confusing and make
metrics look meaningful. Change these to be nan also which, with the
next change, gets shown like:
'''
$ perf stat true
Performance counter stats for 'true':
1.25 msec task-clock:u # 0.387 CPUs utilized
0 context-switches:u # 0.000 /sec
0 cpu-migrations:u # 0.000 /sec
46 page-faults:u # 36.702 K/sec
255,942 cycles:u # 0.204 GHz (88.66%)
123,046 instructions:u # 0.48 insn per cycle
28,301 branches:u # 22.580 M/sec
2,489 branch-misses:u # 8.79% of all branches
4,719 CPU_CLK_UNHALTED.REF_XCLK:u # 3.765 M/sec
# nan % tma_frontend_bound
# nan % tma_retiring
# nan % tma_backend_bound
# nan % tma_bad_speculation
344,855 IDQ_UOPS_NOT_DELIVERED.CORE:u # 275.147 M/sec
<not supported> INT_MISC.RECOVERY_CYCLES_ANY:u
<not counted> CPU_CLK_UNHALTED.ONE_THREAD_ACTIVE:u (0.00%)
<not counted> CPU_CLK_UNHALTED.THREAD:u (0.00%)
<not counted> UOPS_RETIRED.RETIRE_SLOTS:u (0.00%)
<not counted> UOPS_ISSUED.ANY:u (0.00%)
0.003238142 seconds time elapsed
0.000000000 seconds user
0.003434000 seconds sys
'''
Ensure that nan metric values are quoted as nan isn't a valid number
in JSON.
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ahmad Yasin <ahmad.yasin@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Caleb Biggers <caleb.biggers@intel.com>
Cc: Edward Baker <edward.baker@intel.com>
Cc: Florian Fischer <florian.fischer@muhq.space>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kang Minchul <tegongkang@gmail.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Perry Taylor <perry.taylor@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Samantha Alt <samantha.alt@intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Weilin Wang <weilin.wang@intel.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Link: https://lore.kernel.org/r/20230502223851.2234828-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To resolve a trivial merge conflict with c302378bc1 ("libbpf:
Hashmap interface update to allow both long and void* keys/values"),
where a function present upstream was removed in the perf tools
development tree.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
An update for libbpf's hashmap interface from void* -> void* to a
polymorphic one, allowing both long and void* keys and values.
This simplifies many use cases in libbpf as hashmaps there are mostly
integer to integer.
Perf copies hashmap implementation from libbpf and has to be
updated as well.
Changes to libbpf, selftests/bpf and perf are packed as a single
commit to avoid compilation issues with any future bisect.
Polymorphic interface is acheived by hiding hashmap interface
functions behind auxiliary macros that take care of necessary
type casts, for example:
#define hashmap_cast_ptr(p) \
({ \
_Static_assert((p) == NULL || sizeof(*(p)) == sizeof(long),\
#p " pointee should be a long-sized integer or a pointer"); \
(long *)(p); \
})
bool hashmap_find(const struct hashmap *map, long key, long *value);
#define hashmap__find(map, key, value) \
hashmap_find((map), (long)(key), hashmap_cast_ptr(value))
- hashmap__find macro casts key and value parameters to long
and long* respectively
- hashmap_cast_ptr ensures that value pointer points to a memory
of appropriate size.
This hack was suggested by Andrii Nakryiko in [1].
This is a follow up for [2].
[1] https://lore.kernel.org/bpf/CAEf4BzZ8KFneEJxFAaNCCFPGqp20hSpS2aCj76uRk3-qZUH5xg@mail.gmail.com/
[2] https://lore.kernel.org/bpf/af1facf9-7bc8-8a3d-0db4-7b3f333589a2@meta.com/T/#m65b28f1d6d969fcd318b556db6a3ad499a42607d
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221109142611.879983-2-eddyz87@gmail.com
