kernel/tools/perf/util/parse-events.h, branch linux-rolling-stable

perf tools: Add support for perf_event_attr::config4

2025-11-24T20:20:06Z

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

2025-10-15T14:59:11Z

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

2025-10-15T14:59:11Z

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

2025-10-15T14:59:10Z

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

2025-10-15T14:59:10Z

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

2025-10-15T14:59:10Z

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

perf parse-events: Fix legacy cache events if event is duplicated in a PMU

2025-10-15T14:59:10Z

The term list when adding an event to a PMU is expected to have the event name for the alias lookup. Also, set found_supported so that -EINVAL isn't returned. Fixes: 62593394f66a ("perf parse-events: Legacy cache names on all PMUs and lower priority") Tested-by: Thomas Richter Signed-off-by: Ian Rogers Tested-by: James Clark Signed-off-by: Namhyung Kim

perf record: Add ratio-to-prev term

2025-10-03T19:49:51Z

Provide ratio-to-prev term which allows the user to set the event sample period of two events corresponding to a desired ratio. If using on an Intel x86 platform with Auto Counter Reload support, also set corresponding event's config2 attribute with a bitmask which counters to reset and which counters to sample if the desired ratio is met or exceeded. On other platforms, only the sample period is affected by the ratio-to-prev term. Reviewed-by: Ian Rogers Signed-off-by: Thomas Falcon Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Dapeng Mi Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kan Liang Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Signed-off-by: Arnaldo Carvalho de Melo

perf parse-events: Add 'X' modifier to exclude an event from being regrouped

2025-09-12T18:53:32Z

The function parse_events__sort_events_and_fix_groups is needed to fix uncore events like: ``` $ perf stat -e '{data_read,data_write}' ... ``` so that the multiple uncore PMUs have a group each of data_read and data_write events. The same function will perform architecture sorting and group fixing, in particular for Intel topdown/perf-metric events. Grouping multiple perf metric events together causes perf_event_open to fail as the group can only support one. This means command lines like: ``` $ perf stat -e 'slots,slots' ... ``` fail as the slots events are forced into a group together to try to satisfy the perf-metric event constraints. As the user may know better than parse_events__sort_events_and_fix_groups add a 'X' modifier to skip its regrouping behavior. This allows the following to succeed rather than fail on the second slots event being opened: ``` $ perf stat -e 'slots,slots:X' -a sleep 1 Performance counter stats for 'system wide': 6,834,154,071 cpu_core/slots/ (50.13%) 5,548,629,453 cpu_core/slots/X (49.87%) 1.002634606 seconds time elapsed ``` Closes: https://lore.kernel.org/lkml/20250822082233.1850417-1-dapeng1.mi@linux.intel.com/ Reported-by: Dapeng Mi Reported-by: Xudong Hao Reviewed-by: Dapeng Mi Signed-off-by: Ian Rogers Tested-by: Dapeng Mi Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Greg Kroah-Hartman Cc: Howard Chu Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Kan Liang Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Thomas Falcon Cc: Yoshihiro Furudera Signed-off-by: Arnaldo Carvalho de Melo

perf parse-events: Remove non-json software events

2025-07-26T23:31:43Z

Remove the hard coded encodings from parse-events. This has the consequence that software events are matched using the sysfs/json priority, will be case insensitive and will be wildcarded across PMUs. As there were software and hardware types in the parsing code, the removal means software vs hardware logic can be removed and hardware assumed. Now the perf json provides detailed descriptions of software events, remove the previous listing support that didn't contain event descriptions. When globbing is required for the "sw" option in perf list, use string PMU globbing as was done previously for the tool PMU. The output of `perf list sw` command changed like this. Before: List of pre-defined events (to be used in -e or -M): alignment-faults [Software event] bpf-output [Software event] cgroup-switches [Software event] context-switches OR cs [Software event] cpu-clock [Software event] cpu-migrations OR migrations [Software event] dummy [Software event] emulation-faults [Software event] major-faults [Software event] minor-faults [Software event] page-faults OR faults [Software event] task-clock [Software event] After: List of pre-defined events (to be used in -e or -M): software: alignment-faults [Number of kernel handled memory alignment faults. Unit: software] bpf-output [An event used by BPF programs to write to the perf ring buffer. Unit: software] cgroup-switches [Number of context switches to a task in a different cgroup. Unit: software] context-switches [Number of context switches [This event is an alias of cs]. Unit: software] cpu-clock [Per-CPU high-resolution timer based event. Unit: software] cpu-migrations [Number of times a process has migrated to a new CPU [This event is an alias of migrations]. Unit: software] cs [Number of context switches [This event is an alias of context-switches]. Unit: software] dummy [A placeholder event that doesn't count anything. Unit: software] ... Signed-off-by: Ian Rogers Tested-by: Arnaldo Carvalho de Melo Link: https://lore.kernel.org/r/20250725185202.68671-4-irogers@google.com Signed-off-by: Namhyung Kim