kernel/linux.git/tools/perf/util/parse-events.c, branch v6.19.11

perf parse-events: Fix evsel allocation failure

2026-01-06T22:54:24+00:00

If evsel__new_idx() returns NULL, the function currently jumps to label 'out_err'. Here, references to `cpus` and `pmu_cpus` are dropped. Also, resources held by evsel->name and evsel->metric_id are freed. But if evsel__new_idx() returns NULL, it can lead to NULL pointer dereference. Fixes: cd63c22168257a0b ("perf parse-events: Minor __add_event refactoring") Signed-off-by: Faisal Bukhari Reviewed-by: Arnaldo Carvalho de Melo Signed-off-by: Namhyung Kim

perf tools: Add support for perf_event_attr::config4

2025-11-24T20:20:06+00:00

perf_event_attr has gained a new field, config4, so add support for it extending the existing configN support. Reviewed-by: Leo Yan Reviewed-by: Ian Rogers Tested-by: Leo Yan Signed-off-by: James Clark Acked-by: Peter Zijlstra (Intel) Signed-off-by: Namhyung Kim

perf tool_pmu: More accurately set the cpus for tool events

2025-11-18T02:43:09+00:00

The user and system time events can record on different CPUs, but for all other events a single CPU map of just CPU 0 makes sense. In parse-events detect a tool PMU and then pass the perf_event_attr so that the tool_pmu can return CPUs specific for the event. This avoids a CPU map of all online CPUs being used for events like duration_time. Avoiding this avoids the evlist CPUs containing CPUs for which duration_time just gives 0. Minimizing the evlist CPUs can remove unnecessary sched_setaffinity syscalls that delay metric calculations. Signed-off-by: Ian Rogers Signed-off-by: Namhyung Kim

perf parse-events: Add debug logging to perf_event

2025-11-17T07:24:00+00:00

If verbose is enabled and parse_event is called, typically by tests, log failures. Signed-off-by: Ian Rogers Signed-off-by: Namhyung Kim

perf parse-events: Make X modifier more respectful of groups

2025-10-20T04:05:37+00:00

Events with an X modifier were reordered within a group, for example slots was made the leader in: ``` $ perf record -e '{cpu/mem-stores/ppu,cpu/slots/uX}' -- sleep 1 ``` Fix by making `dont_regroup` evsels always use their index for sorting. Make the cur_leader, when fixing the groups, be that of `dont_regroup` evsel so that the `dont_regroup` evsel doesn't become a leader. On a tigerlake this patch corrects this and meets expectations in: ``` $ perf stat -e '{cpu/mem-stores/,cpu/slots/uX}' -a -- sleep 0.1 Performance counter stats for 'system wide': 83,458,652 cpu/mem-stores/ 2,720,854,880 cpu/slots/uX 0.103780587 seconds time elapsed $ perf stat -e 'slots,slots:X' -a -- sleep 0.1 Performance counter stats for 'system wide': 732,042,247 slots (48.96%) 643,288,155 slots:X (51.04%) 0.102731018 seconds time elapsed ``` Closes: https://lore.kernel.org/lkml/18f20d38-070c-4e17-bc90-cf7102e1e53d@linux.intel.com/ Fixes: 035c17893082 ("perf parse-events: Add 'X' modifier to exclude an event from being regrouped") Signed-off-by: Ian Rogers Signed-off-by: Namhyung Kim

perf parse-events: Remove hard coded legacy hardware and cache parsing

2025-10-15T14:59:11+00:00

Now that legacy hardware and cache events are in json, having the lexer match the specific event is no longer necessary and generic PMU parsing can take place. Because of this remove the specific term parsing, event adding, and passing of alternate_hw_config which was now always PERF_COUNT_HW_MAX. This mirrors a similar change for software events in commit 6e9fa4131abb ("perf parse-events: Remove non-json software events"). With no hard coded legacy hardware or cache events the wild card, case insensitivity, etc. is consistent for events. This does, however, mean events like cycles will wild card against all PMUs. A change does the same was originally posted and merged from: https://lore.kernel.org/r/20240416061533.921723-10-irogers@google.com and reverted by Linus in commit 4f1b067359ac ("Revert "perf parse-events: Prefer sysfs/JSON hardware events over legacy"") due to his dislike for the cycles behavior on ARM. Earlier patches in this series make perf record event opening failures non-fatal and hide the cycles event's failure to open on ARM in perf record, so it is expected the behavior will now be transparent in perf record. perf stat with a cycles event will wildcard open the event on all PMUs. As cycles is a "default event", the perf stat behavior for default events was updated to only open them on core/software PMUs. The change to support legacy events with PMUs was done to clean up Intel's hybrid PMU implementation. Having sysfs/json events with increased priority to legacy was requested by Mark Rutland to fix Apple-M PMU issues wrt broken legacy events on that PMU. It was requested that RISC-V be able to add events to the perf tool json so the PMU driver didn't need to map legacy events to config encodings: https://lore.kernel.org/lkml/20240217005738.3744121-1-atishp@rivosinc.com/ A previous series of patches decreasing legacy hardware event priorities was posted in: https://lore.kernel.org/lkml/20250416045117.876775-1-irogers@google.com/ Namhyung Kim mentioned that hardware and software events can be implemented similarly: https://lore.kernel.org/lkml/aIJmJns2lopxf3EK@google.com/ Tested-by: Thomas Richter Signed-off-by: Ian Rogers Tested-by: James Clark Signed-off-by: Namhyung Kim

perf print-events: Remove print_symbol_events

2025-10-15T14:59:11+00:00

Now legacy hardware events are in json there's no need for a specific printing routine that previously served for both hardware and software events. The associated event_symbols_hw is also removed. To support the previous filtered version use an event glob of "legacy hardware" which matches the topic of the json events. Tested-by: Thomas Richter Signed-off-by: Ian Rogers Tested-by: James Clark Signed-off-by: Namhyung Kim

perf parse-events: Add terms for legacy hardware and cache config values

2025-10-15T14:59:10+00:00

Add the PMU terms legacy-hardware-config and legacy-cache-config. These terms are similar to the config term in that their values are assigned to the perf_event_attr config value. They differ in that the PMU type is switched to be either PERF_TYPE_HARDWARE or PERF_TYPE_HW_CACHE, and the PMU type is moved into the extended type information of the config value. This will allow later patches to add legacy events to json. An example use of the terms is in the following: ``` $ perf stat -vv -e 'cpu/legacy-hardware-config=1/,cpu/legacy-cache-config=0x10001/' true Using CPUID GenuineIntel-6-8D-1 Attempt to add: cpu/legacy-hardware-config=0x1/ ..after resolving event: cpu/legacy-hardware-config=0x1/ Attempt to add: cpu/legacy-cache-config=0x10001/ ..after resolving event: cpu/legacy-cache-config=0x10001/ Control descriptor is not initialized ------------------------------------------------------------ perf_event_attr: type 0 (PERF_TYPE_HARDWARE) size 136 config 0x1 (PERF_COUNT_HW_INSTRUCTIONS) sample_type IDENTIFIER read_format TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING disabled 1 inherit 1 enable_on_exec 1 ------------------------------------------------------------ sys_perf_event_open: pid 994937 cpu -1 group_fd -1 flags 0x8 = 3 ------------------------------------------------------------ perf_event_attr: type 3 (PERF_TYPE_HW_CACHE) size 136 config 0x10001 (PERF_COUNT_HW_CACHE_RESULT_MISS | PERF_COUNT_HW_CACHE_OP_READ | PERF_COUNT_HW_CACHE_L1I) sample_type IDENTIFIER read_format TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING disabled 1 inherit 1 enable_on_exec 1 ------------------------------------------------------------ sys_perf_event_open: pid 994937 cpu -1 group_fd -1 flags 0x8 = 4 cpu/legacy-hardware-config=1/: -1: 1364046 414756 414756 cpu/legacy-cache-config=0x10001/: -1: 57453 414756 414756 cpu/legacy-hardware-config=1/: 1364046 414756 414756 cpu/legacy-cache-config=0x10001/: 57453 414756 414756 Performance counter stats for 'true': 1,364,046 cpu/legacy-hardware-config=1/ 57,453 cpu/legacy-cache-config=0x10001/ 0.001988593 seconds time elapsed 0.002194000 seconds user 0.000000000 seconds sys ``` Tested-by: Thomas Richter Signed-off-by: Ian Rogers Tested-by: James Clark Signed-off-by: Namhyung Kim

perf parse-events: Remove unused FILE input argument to scanner

2025-10-15T14:59:10+00:00

Now the events file isn't directly parsed from a FILE but stored in a string prior to parsing, remove the FILE argument to the associated scanner functions as they only ever pass NULL. Tested-by: Thomas Richter Signed-off-by: Ian Rogers Tested-by: James Clark Signed-off-by: Namhyung Kim

perf pmu: Don't eagerly parse event terms

2025-10-15T14:59:10+00:00

When an event/alias is created for a PMU the terms are eagerly parsed using parse_events_terms. For a command like perf stat or perf record, the particular event/alias will be found, the terms parsed, the terms cloned for use in the event parsing, and then the terms used to configure the perf_event_attr. Events/aliases may be eagerly loaded, such as from sysfs or in perf list, in which case the aliases terms will be little or never used. To avoid redundant work, to avoid cloning, and to reduce memory overhead, hold the terms for an event as a string until they need handling as a term list. This may introduce duplicate parsing if an event is repeated in a list, but this situation is expected to be uncommon. Measuring the number of instructions before and after with a sysfs event and perf stat, there is a minor reduction in the number of instructions executed by 0.3%. Tested-by: Thomas Richter Signed-off-by: Ian Rogers Tested-by: James Clark Signed-off-by: Namhyung Kim