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In the function lazily compute whether a symbol is an idle function taking into consideration the kernel version and architecture of the machine. As symbols__insert no longer needs to know if a symbol is for the kernel, remove the argument. This change is inspired by mailing list discussion, particularly from Thomas Richter and Heiko Carstens : https://lore.kernel.org/lkml/20260219113850.354271-1-tmricht@linux.ibm.com/ The change switches x86 matches to use strstarts which means intel_idle_irq is matched as part of strstarts(name, "intel_idle"), a change suggested by Honglei Wang in: https://lore.kernel.org/lkml/20260323085255.98173-1-jameshongleiwang@126.com/ Assisted-by: Gemini:gemini-3.1-pro-preview Signed-off-by: Ian Rogers --- tools/perf/builtin-top.c | 3 +- tools/perf/util/symbol-elf.c | 2 +- tools/perf/util/symbol.c | 114 +++++++++++++++++++++-------------- tools/perf/util/symbol.h | 8 +-- 4 files changed, 74 insertions(+), 53 deletions(-) diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index 9a0c388a7ec3..efb4b1172190 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -830,7 +830,8 @@ static void perf_event__process_sample(const struct perf_tool *tool, } } - if (al.sym == NULL || !symbol__is_idle(al.sym)) { + if (al.sym == NULL || + !symbol__is_idle(al.sym, al.map ? map__dso(al.map) : NULL, machine->env)) { struct hists *hists = evsel__hists(evsel); struct hist_entry_iter iter = { .evsel = evsel, diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index a9045d6fcb95..69484abc07b6 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -1728,7 +1728,7 @@ dso__load_sym_internal(struct dso *dso, struct map *map, struct symsrc *syms_ss, arch__sym_update(f, &sym); - __symbols__insert(dso__symbols(curr_dso), f, dso__kernel(dso)); + __symbols__insert(dso__symbols(curr_dso), f); nr++; } dso__put(curr_dso); diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 4702b8989354..2caa6b8b8609 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -50,7 +50,6 @@ static int dso__load_kernel_sym(struct dso *dso, struct map *map); static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map); -static bool symbol__compute_is_idle(const char *name); int vmlinux_path__nr_entries; char **vmlinux_path; @@ -401,8 +400,7 @@ void symbols__delete(struct rb_root_cached *symbols) } } -void __symbols__insert(struct rb_root_cached *symbols, - struct symbol *sym, bool kernel) +void __symbols__insert(struct rb_root_cached *symbols, struct symbol *sym) { struct rb_node **p = &symbols->rb_root.rb_node; struct rb_node *parent = NULL; @@ -410,17 +408,6 @@ void __symbols__insert(struct rb_root_cached *symbols, struct symbol *s; bool leftmost = true; - if (kernel) { - const char *name = sym->name; - /* - * ppc64 uses function descriptors and appends a '.' to the - * start of every instruction address. Remove it. - */ - if (name[0] == '.') - name++; - symbol__set_idle(sym, symbol__compute_is_idle(name)); - } - while (*p != NULL) { parent = *p; s = rb_entry(parent, struct symbol, rb_node); @@ -437,7 +424,7 @@ void __symbols__insert(struct rb_root_cached *symbols, void symbols__insert(struct rb_root_cached *symbols, struct symbol *sym) { - __symbols__insert(symbols, sym, false); + __symbols__insert(symbols, sym); } static struct symbol *symbols__find(struct rb_root_cached *symbols, u64 ip) @@ -598,7 +585,7 @@ void dso__reset_find_symbol_cache(struct dso *dso) void dso__insert_symbol(struct dso *dso, struct symbol *sym) { - __symbols__insert(dso__symbols(dso), sym, dso__kernel(dso)); + __symbols__insert(dso__symbols(dso), sym); /* update the symbol cache if necessary */ if (dso__last_find_result_addr(dso) >= sym->start && @@ -760,55 +747,90 @@ int modules__parse(const char *filename, void *arg, return err; } -bool symbol__is_idle(const struct symbol *sym) -{ - uint16_t flags = atomic_load(&sym->flags); - uint16_t idle_val = (flags & SYMBOL_FLAG_IDLE_MASK) >> SYMBOL_FLAG_IDLE_SHIFT; - - return idle_val == SYMBOL_IDLE__IDLE; -} - /* * These are symbols in the kernel image, so make sure that * sym is from a kernel DSO. */ -static bool symbol__compute_is_idle(const char *name) +static int sym_name_cmp(const void *a, const void *b) +{ + const char *name = a; + const char *const *sym = b; + + return strcmp(name, *sym); +} + +bool symbol__is_idle(struct symbol *sym, const struct dso *dso, struct perf_env *env) { - const char * const idle_symbols[] = { + static const char * const idle_symbols[] = { "acpi_idle_do_entry", "acpi_processor_ffh_cstate_enter", "arch_cpu_idle", "cpu_idle", "cpu_startup_entry", - "idle_cpu", - "intel_idle", - "intel_idle_ibrs", "default_idle", - "native_safe_halt", "enter_idle", "exit_idle", - "mwait_idle", - "mwait_idle_with_hints", - "mwait_idle_with_hints.constprop.0", + "idle_cpu", + "native_safe_halt", "poll_idle", - "ppc64_runlatch_off", "pseries_dedicated_idle_sleep", - "psw_idle", - "psw_idle_exit", - NULL }; - int i; - static struct strlist *idle_symbols_list; + const char *name = sym->name; + uint16_t e_machine = perf_env__e_machine(env, /*e_flags=*/NULL); + + { + uint16_t flags = atomic_load(&sym->flags); + uint16_t idle_val = (flags & SYMBOL_FLAG_IDLE_MASK) >> SYMBOL_FLAG_IDLE_SHIFT; + + if (idle_val != SYMBOL_IDLE__UNKNOWN) + return idle_val == SYMBOL_IDLE__IDLE; + } + + if (!dso || dso__kernel(dso) == DSO_SPACE__USER) { + symbol__set_idle(sym, /*idle=*/false); + return false; + } + + /* + * ppc64 uses function descriptors and appends a '.' to the + * start of every instruction address. Remove it. + */ + if (name[0] == '.') + name++; + + if (bsearch(name, idle_symbols, ARRAY_SIZE(idle_symbols), + sizeof(idle_symbols[0]), sym_name_cmp)) { + symbol__set_idle(sym, /*idle=*/true); + return true; + } - if (idle_symbols_list) - return strlist__has_entry(idle_symbols_list, name); + if (e_machine == EM_386 || e_machine == EM_X86_64) { + if (strstarts(name, "mwait_idle") || + strstarts(name, "intel_idle")) { + symbol__set_idle(sym, /*idle=*/true); + return true; + } + } - idle_symbols_list = strlist__new(NULL, NULL); + if (e_machine == EM_PPC64 && !strcmp(name, "ppc64_runlatch_off")) { + symbol__set_idle(sym, /*idle=*/true); + return true; + } - for (i = 0; idle_symbols[i]; i++) - strlist__add(idle_symbols_list, idle_symbols[i]); + if (e_machine == EM_S390 && strstarts(name, "psw_idle")) { + int major = 0, minor = 0; + const char *release = perf_env__os_release(env); - return strlist__has_entry(idle_symbols_list, name); + /* Before v6.10, s390 used psw_idle. */ + if (release && sscanf(release, "%d.%d", &major, &minor) == 2 && + (major < 6 || (major == 6 && minor < 10))) { + symbol__set_idle(sym, /*idle=*/true); + return true; + } + } + + symbol__set_idle(sym, /*idle=*/false); + return false; } static int map__process_kallsym_symbol(void *arg, const char *name, @@ -837,7 +859,7 @@ static int map__process_kallsym_symbol(void *arg, const char *name, * We will pass the symbols to the filter later, in * map__split_kallsyms, when we have split the maps per module */ - __symbols__insert(root, sym, !strchr(name, '[')); + __symbols__insert(root, sym); return 0; } diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h index a199646f21f7..422e98a4ea2f 100644 --- a/tools/perf/util/symbol.h +++ b/tools/perf/util/symbol.h @@ -28,6 +28,7 @@ struct map; struct maps; struct option; struct build_id; +struct perf_env; /* * libelf 0.8.x and earlier do not support ELF_C_READ_MMAP; @@ -60,7 +61,6 @@ enum symbol_idle_kind { #define SYMBOL_FLAG_INLINED (1 << 11) #define SYMBOL_FLAG_ANNOTATE2 (1 << 12) #define SYMBOL_FLAG_IFUNC_ALIAS (1 << 13) - /** * A symtab entry. When allocated this may be preceded by an annotation (see * symbol__annotation) and/or a browser_index (see symbol__browser_index). @@ -112,7 +112,7 @@ static inline bool symbol__ifunc_alias(const struct symbol *sym) return (atomic_load(&sym->flags) & SYMBOL_FLAG_IFUNC_ALIAS) != 0; } -bool symbol__is_idle(const struct symbol *sym); +bool symbol__is_idle(struct symbol *sym, const struct dso *dso, struct perf_env *env); void symbol__set_ignore(struct symbol *sym, bool ignore); void symbol__set_annotate2(struct symbol *sym, bool annotate2); @@ -196,7 +196,6 @@ int filename__read_debuglink(const char *filename, char *debuglink, size_t size); bool filename__has_section(const char *filename, const char *sec); -struct perf_env; int symbol__init(struct perf_env *env); void symbol__exit(void); void symbol__elf_init(void); @@ -236,8 +235,7 @@ int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss); char *dso__demangle_sym(struct dso *dso, int kmodule, const char *elf_name); -void __symbols__insert(struct rb_root_cached *symbols, struct symbol *sym, - bool kernel); +void __symbols__insert(struct rb_root_cached *symbols, struct symbol *sym); void symbols__insert(struct rb_root_cached *symbols, struct symbol *sym); void symbols__fixup_duplicate(struct rb_root_cached *symbols); void symbols__fixup_end(struct rb_root_cached *symbols, bool is_kallsyms); -- 2.54.0.545.g6539524ca2-goog