From: Ian Rogers Date: Mon, 25 Aug 2025 21:12:04 +0000 (-0700) Subject: perf parse-events: Add 'X' modifier to exclude an event from being regrouped X-Git-Tag: v6.18-rc1~35^2~126 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=035c17893082b403c98330f1fdb58fd925951038;p=thirdparty%2Flinux.git perf parse-events: Add 'X' modifier to exclude an event from being regrouped 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 --- diff --git a/tools/perf/Documentation/perf-list.txt b/tools/perf/Documentation/perf-list.txt index 28215306a78a..a5039d1614f9 100644 --- a/tools/perf/Documentation/perf-list.txt +++ b/tools/perf/Documentation/perf-list.txt @@ -73,6 +73,7 @@ counted. The following modifiers exist: e - group or event are exclusive and do not share the PMU b - use BPF aggregration (see perf stat --bpf-counters) R - retire latency value of the event + X - don't regroup the event to match PMUs The 'p' modifier can be used for specifying how precise the instruction address should be. The 'p' modifier can be specified multiple times: diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h index e927a3a4fe0e..03f9f22e3a0c 100644 --- a/tools/perf/util/evsel.h +++ b/tools/perf/util/evsel.h @@ -89,6 +89,7 @@ struct evsel { bool use_config_name; bool skippable; bool retire_lat; + bool dont_regroup; int bpf_fd; struct bpf_object *bpf_obj; struct list_head config_terms; diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c index 0026cff4d69e..452f12191f6e 100644 --- a/tools/perf/util/parse-events.c +++ b/tools/perf/util/parse-events.c @@ -1896,6 +1896,8 @@ static int parse_events__modifier_list(struct parse_events_state *parse_state, evsel->bpf_counter = true; if (mod.retire_lat) evsel->retire_lat = true; + if (mod.dont_regroup) + evsel->dont_regroup = true; } return 0; } @@ -2192,13 +2194,12 @@ static int parse_events__sort_events_and_fix_groups(struct list_head *list) * Set the group leader respecting the given groupings and that * groups can't span PMUs. */ - if (!cur_leader) { + if (!cur_leader || pos->dont_regroup) { cur_leader = pos; cur_leaders_grp = &pos->core; if (pos_force_grouped) force_grouped_leader = pos; } - cur_leader_pmu_name = cur_leader->group_pmu_name; if (strcmp(cur_leader_pmu_name, pos_pmu_name)) { /* PMU changed so the group/leader must change. */ diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h index 62dc7202e3ba..a5c5fc39fd6f 100644 --- a/tools/perf/util/parse-events.h +++ b/tools/perf/util/parse-events.h @@ -216,6 +216,7 @@ struct parse_events_modifier { bool guest : 1; /* 'G' */ bool host : 1; /* 'H' */ bool retire_lat : 1; /* 'R' */ + bool dont_regroup : 1; /* 'X' */ }; int parse_events__modifier_event(struct parse_events_state *parse_state, void *loc, diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l index 2034590eb789..294e943bcdb4 100644 --- a/tools/perf/util/parse-events.l +++ b/tools/perf/util/parse-events.l @@ -206,6 +206,7 @@ static int modifiers(struct parse_events_state *parse_state, yyscan_t scanner) CASE('e', exclusive); CASE('b', bpf); CASE('R', retire_lat); + CASE('X', dont_regroup); default: return PE_ERROR; } @@ -251,10 +252,10 @@ term_name {name_start}[a-zA-Z0-9_*?.\[\]!\-:]* quoted_name [\']{name_start}[a-zA-Z0-9_*?.\[\]!\-:,\.=]*[\'] drv_cfg_term [a-zA-Z0-9_\.]+(=[a-zA-Z0-9_*?\.:]+)? /* - * If you add a modifier you need to update check_modifier(). + * If you add a modifier you need to update modifiers(). * Also, the letters in modifier_event must not be in modifier_bp. */ -modifier_event [ukhpPGHSDIWebR]{1,16} +modifier_event [ukhpPGHSDIWebRX]{1,17} modifier_bp [rwx]{1,3} lc_type (L1-dcache|l1-d|l1d|L1-data|L1-icache|l1-i|l1i|L1-instruction|LLC|L2|dTLB|d-tlb|Data-TLB|iTLB|i-tlb|Instruction-TLB|branch|branches|bpu|btb|bpc|node) lc_op_result (load|loads|read|store|stores|write|prefetch|prefetches|speculative-read|speculative-load|refs|Reference|ops|access|misses|miss)