diff options
author | Ingo Molnar <mingo@kernel.org> | 2016-06-08 09:29:23 +0200 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2016-06-08 09:29:23 +0200 |
commit | aa3a655b159f11b1afe0dcdac5fb5b172f02b778 (patch) | |
tree | 577058fb95c7f2e2aacb3566874e75e17fcec9f8 /tools/perf | |
parent | 616d1c1b98ac79f30216a57a170dd7cea19b3df3 (diff) | |
parent | 7db91f251056f90fec4121f028680ab3153a0f3c (diff) | |
download | linux-stable-aa3a655b159f11b1afe0dcdac5fb5b172f02b778.tar.gz linux-stable-aa3a655b159f11b1afe0dcdac5fb5b172f02b778.tar.bz2 linux-stable-aa3a655b159f11b1afe0dcdac5fb5b172f02b778.zip |
Merge tag 'perf-core-for-mingo-20160606' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
User visible changes:
- Tooling support for TopDown counters, recently added to the kernel (Andi Kleen)
- Show call graphs in 'perf script' when 1st event doesn't have it but some other has (He Kuang)
- Fix terminal cleanup when handling invalid .perfconfig files in 'perf top' (Taeung Song)
Build fixes:
- Respect CROSS_COMPILE for the linker in libapi (Lucas Stach)
Infrastructure changes:
- Fix perf_evlist__alloc_mmap() failure path (Wang Nan)
- Provide way to extract integer value from format_field (Arnaldo Carvalho de Melo)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools/perf')
-rw-r--r-- | tools/perf/Documentation/perf-stat.txt | 32 | ||||
-rw-r--r-- | tools/perf/arch/x86/util/Build | 1 | ||||
-rw-r--r-- | tools/perf/arch/x86/util/group.c | 27 | ||||
-rw-r--r-- | tools/perf/builtin-script.c | 23 | ||||
-rw-r--r-- | tools/perf/builtin-stat.c | 165 | ||||
-rw-r--r-- | tools/perf/tests/parse-events.c | 4 | ||||
-rw-r--r-- | tools/perf/util/config.c | 22 | ||||
-rw-r--r-- | tools/perf/util/evlist.c | 5 | ||||
-rw-r--r-- | tools/perf/util/evsel.c | 25 | ||||
-rw-r--r-- | tools/perf/util/evsel.h | 2 | ||||
-rw-r--r-- | tools/perf/util/group.h | 7 | ||||
-rw-r--r-- | tools/perf/util/parse-events.l | 1 | ||||
-rw-r--r-- | tools/perf/util/stat-shadow.c | 162 | ||||
-rw-r--r-- | tools/perf/util/stat.c | 5 | ||||
-rw-r--r-- | tools/perf/util/stat.h | 5 |
15 files changed, 440 insertions, 46 deletions
diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt index 04f23b404bbc..d96ccd4844df 100644 --- a/tools/perf/Documentation/perf-stat.txt +++ b/tools/perf/Documentation/perf-stat.txt @@ -204,6 +204,38 @@ Aggregate counts per physical processor for system-wide mode measurements. --no-aggr:: Do not aggregate counts across all monitored CPUs. +--topdown:: +Print top down level 1 metrics if supported by the CPU. This allows to +determine bottle necks in the CPU pipeline for CPU bound workloads, +by breaking the cycles consumed down into frontend bound, backend bound, +bad speculation and retiring. + +Frontend bound means that the CPU cannot fetch and decode instructions fast +enough. Backend bound means that computation or memory access is the bottle +neck. Bad Speculation means that the CPU wasted cycles due to branch +mispredictions and similar issues. Retiring means that the CPU computed without +an apparently bottleneck. The bottleneck is only the real bottleneck +if the workload is actually bound by the CPU and not by something else. + +For best results it is usually a good idea to use it with interval +mode like -I 1000, as the bottleneck of workloads can change often. + +The top down metrics are collected per core instead of per +CPU thread. Per core mode is automatically enabled +and -a (global monitoring) is needed, requiring root rights or +perf.perf_event_paranoid=-1. + +Topdown uses the full Performance Monitoring Unit, and needs +disabling of the NMI watchdog (as root): +echo 0 > /proc/sys/kernel/nmi_watchdog +for best results. Otherwise the bottlenecks may be inconsistent +on workload with changing phases. + +This enables --metric-only, unless overriden with --no-metric-only. + +To interpret the results it is usually needed to know on which +CPUs the workload runs on. If needed the CPUs can be forced using +taskset. EXAMPLES -------- diff --git a/tools/perf/arch/x86/util/Build b/tools/perf/arch/x86/util/Build index 465970370f3e..4cd8a16b1b7b 100644 --- a/tools/perf/arch/x86/util/Build +++ b/tools/perf/arch/x86/util/Build @@ -3,6 +3,7 @@ libperf-y += tsc.o libperf-y += pmu.o libperf-y += kvm-stat.o libperf-y += perf_regs.o +libperf-y += group.o libperf-$(CONFIG_DWARF) += dwarf-regs.o libperf-$(CONFIG_BPF_PROLOGUE) += dwarf-regs.o diff --git a/tools/perf/arch/x86/util/group.c b/tools/perf/arch/x86/util/group.c new file mode 100644 index 000000000000..37f92aa39a5d --- /dev/null +++ b/tools/perf/arch/x86/util/group.c @@ -0,0 +1,27 @@ +#include <stdio.h> +#include "api/fs/fs.h" +#include "util/group.h" + +/* + * Check whether we can use a group for top down. + * Without a group may get bad results due to multiplexing. + */ +bool arch_topdown_check_group(bool *warn) +{ + int n; + + if (sysctl__read_int("kernel/nmi_watchdog", &n) < 0) + return false; + if (n > 0) { + *warn = true; + return false; + } + return true; +} + +void arch_topdown_group_warn(void) +{ + fprintf(stderr, + "nmi_watchdog enabled with topdown. May give wrong results.\n" + "Disable with echo 0 > /proc/sys/kernel/nmi_watchdog\n"); +} diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c index e3ce2f34d3ad..46011235af5d 100644 --- a/tools/perf/builtin-script.c +++ b/tools/perf/builtin-script.c @@ -339,7 +339,7 @@ static void set_print_ip_opts(struct perf_event_attr *attr) */ static int perf_session__check_output_opt(struct perf_session *session) { - int j; + unsigned int j; struct perf_evsel *evsel; for (j = 0; j < PERF_TYPE_MAX; ++j) { @@ -388,17 +388,20 @@ static int perf_session__check_output_opt(struct perf_session *session) struct perf_event_attr *attr; j = PERF_TYPE_TRACEPOINT; - evsel = perf_session__find_first_evtype(session, j); - if (evsel == NULL) - goto out; - attr = &evsel->attr; + evlist__for_each(session->evlist, evsel) { + if (evsel->attr.type != j) + continue; + + attr = &evsel->attr; - if (attr->sample_type & PERF_SAMPLE_CALLCHAIN) { - output[j].fields |= PERF_OUTPUT_IP; - output[j].fields |= PERF_OUTPUT_SYM; - output[j].fields |= PERF_OUTPUT_DSO; - set_print_ip_opts(attr); + if (attr->sample_type & PERF_SAMPLE_CALLCHAIN) { + output[j].fields |= PERF_OUTPUT_IP; + output[j].fields |= PERF_OUTPUT_SYM; + output[j].fields |= PERF_OUTPUT_DSO; + set_print_ip_opts(attr); + goto out; + } } } diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index ee7ada78d86f..dff63733dfb7 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -59,10 +59,13 @@ #include "util/thread.h" #include "util/thread_map.h" #include "util/counts.h" +#include "util/group.h" #include "util/session.h" #include "util/tool.h" +#include "util/group.h" #include "asm/bug.h" +#include <api/fs/fs.h> #include <stdlib.h> #include <sys/prctl.h> #include <locale.h> @@ -98,6 +101,15 @@ static const char * transaction_limited_attrs = { "}" }; +static const char * topdown_attrs[] = { + "topdown-total-slots", + "topdown-slots-retired", + "topdown-recovery-bubbles", + "topdown-fetch-bubbles", + "topdown-slots-issued", + NULL, +}; + static struct perf_evlist *evsel_list; static struct target target = { @@ -112,6 +124,7 @@ static volatile pid_t child_pid = -1; static bool null_run = false; static int detailed_run = 0; static bool transaction_run; +static bool topdown_run = false; static bool big_num = true; static int big_num_opt = -1; static const char *csv_sep = NULL; @@ -124,6 +137,7 @@ static unsigned int initial_delay = 0; static unsigned int unit_width = 4; /* strlen("unit") */ static bool forever = false; static bool metric_only = false; +static bool force_metric_only = false; static struct timespec ref_time; static struct cpu_map *aggr_map; static aggr_get_id_t aggr_get_id; @@ -1302,7 +1316,15 @@ static int aggr_header_lens[] = { [AGGR_GLOBAL] = 0, }; -static void print_metric_headers(char *prefix) +static const char *aggr_header_csv[] = { + [AGGR_CORE] = "core,cpus,", + [AGGR_SOCKET] = "socket,cpus", + [AGGR_NONE] = "cpu,", + [AGGR_THREAD] = "comm-pid,", + [AGGR_GLOBAL] = "" +}; + +static void print_metric_headers(const char *prefix, bool no_indent) { struct perf_stat_output_ctx out; struct perf_evsel *counter; @@ -1313,9 +1335,15 @@ static void print_metric_headers(char *prefix) if (prefix) fprintf(stat_config.output, "%s", prefix); - if (!csv_output) + if (!csv_output && !no_indent) fprintf(stat_config.output, "%*s", aggr_header_lens[stat_config.aggr_mode], ""); + if (csv_output) { + if (stat_config.interval) + fputs("time,", stat_config.output); + fputs(aggr_header_csv[stat_config.aggr_mode], + stat_config.output); + } /* Print metrics headers only */ evlist__for_each(evsel_list, counter) { @@ -1338,28 +1366,40 @@ static void print_interval(char *prefix, struct timespec *ts) sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, csv_sep); - if (num_print_interval == 0 && !csv_output && !metric_only) { + if (num_print_interval == 0 && !csv_output) { switch (stat_config.aggr_mode) { case AGGR_SOCKET: - fprintf(output, "# time socket cpus counts %*s events\n", unit_width, "unit"); + fprintf(output, "# time socket cpus"); + if (!metric_only) + fprintf(output, " counts %*s events\n", unit_width, "unit"); break; case AGGR_CORE: - fprintf(output, "# time core cpus counts %*s events\n", unit_width, "unit"); + fprintf(output, "# time core cpus"); + if (!metric_only) + fprintf(output, " counts %*s events\n", unit_width, "unit"); break; case AGGR_NONE: - fprintf(output, "# time CPU counts %*s events\n", unit_width, "unit"); + fprintf(output, "# time CPU"); + if (!metric_only) + fprintf(output, " counts %*s events\n", unit_width, "unit"); break; case AGGR_THREAD: - fprintf(output, "# time comm-pid counts %*s events\n", unit_width, "unit"); + fprintf(output, "# time comm-pid"); + if (!metric_only) + fprintf(output, " counts %*s events\n", unit_width, "unit"); break; case AGGR_GLOBAL: default: - fprintf(output, "# time counts %*s events\n", unit_width, "unit"); + fprintf(output, "# time"); + if (!metric_only) + fprintf(output, " counts %*s events\n", unit_width, "unit"); case AGGR_UNSET: break; } } + if (num_print_interval == 0 && metric_only) + print_metric_headers(" ", true); if (++num_print_interval == 25) num_print_interval = 0; } @@ -1428,8 +1468,8 @@ static void print_counters(struct timespec *ts, int argc, const char **argv) if (metric_only) { static int num_print_iv; - if (num_print_iv == 0) - print_metric_headers(prefix); + if (num_print_iv == 0 && !interval) + print_metric_headers(prefix, false); if (num_print_iv++ == 25) num_print_iv = 0; if (stat_config.aggr_mode == AGGR_GLOBAL && prefix) @@ -1520,6 +1560,14 @@ static int stat__set_big_num(const struct option *opt __maybe_unused, return 0; } +static int enable_metric_only(const struct option *opt __maybe_unused, + const char *s __maybe_unused, int unset) +{ + force_metric_only = true; + metric_only = !unset; + return 0; +} + static const struct option stat_options[] = { OPT_BOOLEAN('T', "transaction", &transaction_run, "hardware transaction statistics"), @@ -1578,8 +1626,10 @@ static const struct option stat_options[] = { "aggregate counts per thread", AGGR_THREAD), OPT_UINTEGER('D', "delay", &initial_delay, "ms to wait before starting measurement after program start"), - OPT_BOOLEAN(0, "metric-only", &metric_only, - "Only print computed metrics. No raw values"), + OPT_CALLBACK_NOOPT(0, "metric-only", &metric_only, NULL, + "Only print computed metrics. No raw values", enable_metric_only), + OPT_BOOLEAN(0, "topdown", &topdown_run, + "measure topdown level 1 statistics"), OPT_END() }; @@ -1772,12 +1822,62 @@ static int perf_stat_init_aggr_mode_file(struct perf_stat *st) return 0; } +static int topdown_filter_events(const char **attr, char **str, bool use_group) +{ + int off = 0; + int i; + int len = 0; + char *s; + + for (i = 0; attr[i]; i++) { + if (pmu_have_event("cpu", attr[i])) { + len += strlen(attr[i]) + 1; + attr[i - off] = attr[i]; + } else + off++; + } + attr[i - off] = NULL; + + *str = malloc(len + 1 + 2); + if (!*str) + return -1; + s = *str; + if (i - off == 0) { + *s = 0; + return 0; + } + if (use_group) + *s++ = '{'; + for (i = 0; attr[i]; i++) { + strcpy(s, attr[i]); + s += strlen(s); + *s++ = ','; + } + if (use_group) { + s[-1] = '}'; + *s = 0; + } else + s[-1] = 0; + return 0; +} + +__weak bool arch_topdown_check_group(bool *warn) +{ + *warn = false; + return false; +} + +__weak void arch_topdown_group_warn(void) +{ +} + /* * Add default attributes, if there were no attributes specified or * if -d/--detailed, -d -d or -d -d -d is used: */ static int add_default_attributes(void) { + int err; struct perf_event_attr default_attrs0[] = { { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_TASK_CLOCK }, @@ -1896,7 +1996,6 @@ static int add_default_attributes(void) return 0; if (transaction_run) { - int err; if (pmu_have_event("cpu", "cycles-ct") && pmu_have_event("cpu", "el-start")) err = parse_events(evsel_list, transaction_attrs, NULL); @@ -1909,6 +2008,46 @@ static int add_default_attributes(void) return 0; } + if (topdown_run) { + char *str = NULL; + bool warn = false; + + if (stat_config.aggr_mode != AGGR_GLOBAL && + stat_config.aggr_mode != AGGR_CORE) { + pr_err("top down event configuration requires --per-core mode\n"); + return -1; + } + stat_config.aggr_mode = AGGR_CORE; + if (nr_cgroups || !target__has_cpu(&target)) { + pr_err("top down event configuration requires system-wide mode (-a)\n"); + return -1; + } + + if (!force_metric_only) + metric_only = true; + if (topdown_filter_events(topdown_attrs, &str, + arch_topdown_check_group(&warn)) < 0) { + pr_err("Out of memory\n"); + return -1; + } + if (topdown_attrs[0] && str) { + if (warn) + arch_topdown_group_warn(); + err = parse_events(evsel_list, str, NULL); + if (err) { + fprintf(stderr, + "Cannot set up top down events %s: %d\n", + str, err); + free(str); + return -1; + } + } else { + fprintf(stderr, "System does not support topdown\n"); + return -1; + } + free(str); + } + if (!evsel_list->nr_entries) { if (target__has_cpu(&target)) default_attrs0[0].config = PERF_COUNT_SW_CPU_CLOCK; diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c index 7865f68dc0d8..b2a2c74136a5 100644 --- a/tools/perf/tests/parse-events.c +++ b/tools/perf/tests/parse-events.c @@ -1783,8 +1783,8 @@ static int test_pmu_events(void) struct evlist_test e; char name[MAX_NAME]; - if (!strcmp(ent->d_name, ".") || - !strcmp(ent->d_name, "..")) + /* Names containing . are special and cannot be used directly */ + if (strchr(ent->d_name, '.')) continue; snprintf(name, MAX_NAME, "cpu/event=%s/u", ent->d_name); diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c index dad7d8272168..c73f1c4d1ca9 100644 --- a/tools/perf/util/config.c +++ b/tools/perf/util/config.c @@ -275,7 +275,8 @@ static int perf_parse_file(config_fn_t fn, void *data) break; } } - die("bad config file line %d in %s", config_linenr, config_file_name); + pr_err("bad config file line %d in %s\n", config_linenr, config_file_name); + return -1; } static int parse_unit_factor(const char *end, unsigned long *val) @@ -479,16 +480,15 @@ static int perf_config_global(void) int perf_config(config_fn_t fn, void *data) { - int ret = 0, found = 0; + int ret = -1; const char *home = NULL; /* Setting $PERF_CONFIG makes perf read _only_ the given config file. */ if (config_exclusive_filename) return perf_config_from_file(fn, config_exclusive_filename, data); if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) { - ret += perf_config_from_file(fn, perf_etc_perfconfig(), - data); - found += 1; + if (perf_config_from_file(fn, perf_etc_perfconfig(), data) < 0) + goto out; } home = getenv("HOME"); @@ -514,14 +514,12 @@ int perf_config(config_fn_t fn, void *data) if (!st.st_size) goto out_free; - ret += perf_config_from_file(fn, user_config, data); - found += 1; + ret = perf_config_from_file(fn, user_config, data); + out_free: free(user_config); } out: - if (found == 0) - return -1; return ret; } @@ -609,8 +607,12 @@ static int collect_config(const char *var, const char *value, struct perf_config_section *section = NULL; struct perf_config_item *item = NULL; struct perf_config_set *set = perf_config_set; - struct list_head *sections = &set->sections; + struct list_head *sections; + + if (set == NULL) + return -1; + sections = &set->sections; key = ptr = strdup(var); if (!key) { pr_debug("%s: strdup failed\n", __func__); diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index e0f30946ed1a..1b918aa075d6 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -946,9 +946,12 @@ static int perf_evlist__alloc_mmap(struct perf_evlist *evlist) if (cpu_map__empty(evlist->cpus)) evlist->nr_mmaps = thread_map__nr(evlist->threads); evlist->mmap = zalloc(evlist->nr_mmaps * sizeof(struct perf_mmap)); + if (!evlist->mmap) + return -ENOMEM; + for (i = 0; i < evlist->nr_mmaps; i++) evlist->mmap[i].fd = -1; - return evlist->mmap != NULL ? 0 : -ENOMEM; + return 0; } struct mmap_params { diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 18e18f1d435e..9b2e3e624efe 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -2251,17 +2251,11 @@ void *perf_evsel__rawptr(struct perf_evsel *evsel, struct perf_sample *sample, return sample->raw_data + offset; } -u64 perf_evsel__intval(struct perf_evsel *evsel, struct perf_sample *sample, - const char *name) +u64 format_field__intval(struct format_field *field, struct perf_sample *sample, + bool needs_swap) { - struct format_field *field = perf_evsel__field(evsel, name); - void *ptr; u64 value; - - if (!field) - return 0; - - ptr = sample->raw_data + field->offset; + void *ptr = sample->raw_data + field->offset; switch (field->size) { case 1: @@ -2279,7 +2273,7 @@ u64 perf_evsel__intval(struct perf_evsel *evsel, struct perf_sample *sample, return 0; } - if (!evsel->needs_swap) + if (!needs_swap) return value; switch (field->size) { @@ -2296,6 +2290,17 @@ u64 perf_evsel__intval(struct perf_evsel *evsel, struct perf_sample *sample, return 0; } +u64 perf_evsel__intval(struct perf_evsel *evsel, struct perf_sample *sample, + const char *name) +{ + struct format_field *field = perf_evsel__field(evsel, name); + + if (!field) + return 0; + + return field ? format_field__intval(field, sample, evsel->needs_swap) : 0; +} + bool perf_evsel__fallback(struct perf_evsel *evsel, int err, char *msg, size_t msgsize) { diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h index 028412b32d5a..828ddd1c8947 100644 --- a/tools/perf/util/evsel.h +++ b/tools/perf/util/evsel.h @@ -261,6 +261,8 @@ static inline char *perf_evsel__strval(struct perf_evsel *evsel, struct format_field; +u64 format_field__intval(struct format_field *field, struct perf_sample *sample, bool needs_swap); + struct format_field *perf_evsel__field(struct perf_evsel *evsel, const char *name); #define perf_evsel__match(evsel, t, c) \ diff --git a/tools/perf/util/group.h b/tools/perf/util/group.h new file mode 100644 index 000000000000..116debe7a995 --- /dev/null +++ b/tools/perf/util/group.h @@ -0,0 +1,7 @@ +#ifndef GROUP_H +#define GROUP_H 1 + +bool arch_topdown_check_group(bool *warn); +void arch_topdown_group_warn(void); + +#endif diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l index 01af1ee90a27..3c15b33b2e84 100644 --- a/tools/perf/util/parse-events.l +++ b/tools/perf/util/parse-events.l @@ -260,6 +260,7 @@ cycles-ct { return str(yyscanner, PE_KERNEL_PMU_EVENT); } cycles-t { return str(yyscanner, PE_KERNEL_PMU_EVENT); } mem-loads { return str(yyscanner, PE_KERNEL_PMU_EVENT); } mem-stores { return str(yyscanner, PE_KERNEL_PMU_EVENT); } +topdown-[a-z-]+ { return str(yyscanner, PE_KERNEL_PMU_EVENT); } L1-dcache|l1-d|l1d|L1-data | L1-icache|l1-i|l1i|L1-instruction | diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c index aa9efe08762b..8a2bbd2a4d82 100644 --- a/tools/perf/util/stat-shadow.c +++ b/tools/perf/util/stat-shadow.c @@ -36,6 +36,11 @@ static struct stats runtime_dtlb_cache_stats[NUM_CTX][MAX_NR_CPUS]; static struct stats runtime_cycles_in_tx_stats[NUM_CTX][MAX_NR_CPUS]; static struct stats runtime_transaction_stats[NUM_CTX][MAX_NR_CPUS]; static struct stats runtime_elision_stats[NUM_CTX][MAX_NR_CPUS]; +static struct stats runtime_topdown_total_slots[NUM_CTX][MAX_NR_CPUS]; +static struct stats runtime_topdown_slots_issued[NUM_CTX][MAX_NR_CPUS]; +static struct stats runtime_topdown_slots_retired[NUM_CTX][MAX_NR_CPUS]; +static struct stats runtime_topdown_fetch_bubbles[NUM_CTX][MAX_NR_CPUS]; +static struct stats runtime_topdown_recovery_bubbles[NUM_CTX][MAX_NR_CPUS]; static bool have_frontend_stalled; struct stats walltime_nsecs_stats; @@ -82,6 +87,11 @@ void perf_stat__reset_shadow_stats(void) sizeof(runtime_transaction_stats)); memset(runtime_elision_stats, 0, sizeof(runtime_elision_stats)); memset(&walltime_nsecs_stats, 0, sizeof(walltime_nsecs_stats)); + memset(runtime_topdown_total_slots, 0, sizeof(runtime_topdown_total_slots)); + memset(runtime_topdown_slots_retired, 0, sizeof(runtime_topdown_slots_retired)); + memset(runtime_topdown_slots_issued, 0, sizeof(runtime_topdown_slots_issued)); + memset(runtime_topdown_fetch_bubbles, 0, sizeof(runtime_topdown_fetch_bubbles)); + memset(runtime_topdown_recovery_bubbles, 0, sizeof(runtime_topdown_recovery_bubbles)); } /* @@ -105,6 +115,16 @@ void perf_stat__update_shadow_stats(struct perf_evsel *counter, u64 *count, update_stats(&runtime_transaction_stats[ctx][cpu], count[0]); else if (perf_stat_evsel__is(counter, ELISION_START)) update_stats(&runtime_elision_stats[ctx][cpu], count[0]); + else if (perf_stat_evsel__is(counter, TOPDOWN_TOTAL_SLOTS)) + update_stats(&runtime_topdown_total_slots[ctx][cpu], count[0]); + else if (perf_stat_evsel__is(counter, TOPDOWN_SLOTS_ISSUED)) + update_stats(&runtime_topdown_slots_issued[ctx][cpu], count[0]); + else if (perf_stat_evsel__is(counter, TOPDOWN_SLOTS_RETIRED)) + update_stats(&runtime_topdown_slots_retired[ctx][cpu], count[0]); + else if (perf_stat_evsel__is(counter, TOPDOWN_FETCH_BUBBLES)) + update_stats(&runtime_topdown_fetch_bubbles[ctx][cpu],count[0]); + else if (perf_stat_evsel__is(counter, TOPDOWN_RECOVERY_BUBBLES)) + update_stats(&runtime_topdown_recovery_bubbles[ctx][cpu], count[0]); else if (perf_evsel__match(counter, HARDWARE, HW_STALLED_CYCLES_FRONTEND)) update_stats(&runtime_stalled_cycles_front_stats[ctx][cpu], count[0]); else if (perf_evsel__match(counter, HARDWARE, HW_STALLED_CYCLES_BACKEND)) @@ -302,6 +322,107 @@ static void print_ll_cache_misses(int cpu, out->print_metric(out->ctx, color, "%7.2f%%", "of all LL-cache hits", ratio); } +/* + * High level "TopDown" CPU core pipe line bottleneck break down. + * + * Basic concept following + * Yasin, A Top Down Method for Performance analysis and Counter architecture + * ISPASS14 + * + * The CPU pipeline is divided into 4 areas that can be bottlenecks: + * + * Frontend -> Backend -> Retiring + * BadSpeculation in addition means out of order execution that is thrown away + * (for example branch mispredictions) + * Frontend is instruction decoding. + * Backend is execution, like computation and accessing data in memory + * Retiring is good execution that is not directly bottlenecked + * + * The formulas are computed in slots. + * A slot is an entry in the pipeline each for the pipeline width + * (for example a 4-wide pipeline has 4 slots for each cycle) + * + * Formulas: + * BadSpeculation = ((SlotsIssued - SlotsRetired) + RecoveryBubbles) / + * TotalSlots + * Retiring = SlotsRetired / TotalSlots + * FrontendBound = FetchBubbles / TotalSlots + * BackendBound = 1.0 - BadSpeculation - Retiring - FrontendBound + * + * The kernel provides the mapping to the low level CPU events and any scaling + * needed for the CPU pipeline width, for example: + * + * TotalSlots = Cycles * 4 + * + * The scaling factor is communicated in the sysfs unit. + * + * In some cases the CPU may not be able to measure all the formulas due to + * missing events. In this case multiple formulas are combined, as possible. + * + * Full TopDown supports more levels to sub-divide each area: for example + * BackendBound into computing bound and memory bound. For now we only + * support Level 1 TopDown. + */ + +static double sanitize_val(double x) +{ + if (x < 0 && x >= -0.02) + return 0.0; + return x; +} + +static double td_total_slots(int ctx, int cpu) +{ + return avg_stats(&runtime_topdown_total_slots[ctx][cpu]); +} + +static double td_bad_spec(int ctx, int cpu) +{ + double bad_spec = 0; + double total_slots; + double total; + + total = avg_stats(&runtime_topdown_slots_issued[ctx][cpu]) - + avg_stats(&runtime_topdown_slots_retired[ctx][cpu]) + + avg_stats(&runtime_topdown_recovery_bubbles[ctx][cpu]); + total_slots = td_total_slots(ctx, cpu); + if (total_slots) + bad_spec = total / total_slots; + return sanitize_val(bad_spec); +} + +static double td_retiring(int ctx, int cpu) +{ + double retiring = 0; + double total_slots = td_total_slots(ctx, cpu); + double ret_slots = avg_stats(&runtime_topdown_slots_retired[ctx][cpu]); + + if (total_slots) + retiring = ret_slots / total_slots; + return retiring; +} + +static double td_fe_bound(int ctx, int cpu) +{ + double fe_bound = 0; + double total_slots = td_total_slots(ctx, cpu); + double fetch_bub = avg_stats(&runtime_topdown_fetch_bubbles[ctx][cpu]); + + if (total_slots) + fe_bound = fetch_bub / total_slots; + return fe_bound; +} + +static double td_be_bound(int ctx, int cpu) +{ + double sum = (td_fe_bound(ctx, cpu) + + td_bad_spec(ctx, cpu) + + td_retiring(ctx, cpu)); + if (sum == 0) + return 0; + return sanitize_val(1.0 - sum); +} + void perf_stat__print_shadow_stats(struct perf_evsel *evsel, double avg, int cpu, struct perf_stat_output_ctx *out) @@ -309,6 +430,7 @@ void perf_stat__print_shadow_stats(struct perf_evsel *evsel, void *ctxp = out->ctx; print_metric_t print_metric = out->print_metric; double total, ratio = 0.0, total2; + const char *color = NULL; int ctx = evsel_context(evsel); if (perf_evsel__match(evsel, HARDWARE, HW_INSTRUCTIONS)) { @@ -452,6 +574,46 @@ void perf_stat__print_shadow_stats(struct perf_evsel *evsel, avg / ratio); else print_metric(ctxp, NULL, NULL, "CPUs utilized", 0); + } else if (perf_stat_evsel__is(evsel, TOPDOWN_FETCH_BUBBLES)) { + double fe_bound = td_fe_bound(ctx, cpu); + + if (fe_bound > 0.2) + color = PERF_COLOR_RED; + print_metric(ctxp, color, "%8.1f%%", "frontend bound", + fe_bound * 100.); + } else if (perf_stat_evsel__is(evsel, TOPDOWN_SLOTS_RETIRED)) { + double retiring = td_retiring(ctx, cpu); + + if (retiring > 0.7) + color = PERF_COLOR_GREEN; + print_metric(ctxp, color, "%8.1f%%", "retiring", + retiring * 100.); + } else if (perf_stat_evsel__is(evsel, TOPDOWN_RECOVERY_BUBBLES)) { + double bad_spec = td_bad_spec(ctx, cpu); + + if (bad_spec > 0.1) + color = PERF_COLOR_RED; + print_metric(ctxp, color, "%8.1f%%", "bad speculation", + bad_spec * 100.); + } else if (perf_stat_evsel__is(evsel, TOPDOWN_SLOTS_ISSUED)) { + double be_bound = td_be_bound(ctx, cpu); + const char *name = "backend bound"; + static int have_recovery_bubbles = -1; + + /* In case the CPU does not support topdown-recovery-bubbles */ + if (have_recovery_bubbles < 0) + have_recovery_bubbles = pmu_have_event("cpu", + "topdown-recovery-bubbles"); + if (!have_recovery_bubbles) + name = "backend bound/bad spec"; + + if (be_bound > 0.2) + color = PERF_COLOR_RED; + if (td_total_slots(ctx, cpu) > 0) + print_metric(ctxp, color, "%8.1f%%", name, + be_bound * 100.); + else + print_metric(ctxp, NULL, NULL, name, 0); } else if (runtime_nsecs_stats[cpu].n != 0) { char unit = 'M'; char unit_buf[10]; diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c index ffa1d0653861..c1ba255f2abe 100644 --- a/tools/perf/util/stat.c +++ b/tools/perf/util/stat.c @@ -79,6 +79,11 @@ static const char *id_str[PERF_STAT_EVSEL_ID__MAX] = { ID(TRANSACTION_START, cpu/tx-start/), ID(ELISION_START, cpu/el-start/), ID(CYCLES_IN_TX_CP, cpu/cycles-ct/), + ID(TOPDOWN_TOTAL_SLOTS, topdown-total-slots), + ID(TOPDOWN_SLOTS_ISSUED, topdown-slots-issued), + ID(TOPDOWN_SLOTS_RETIRED, topdown-slots-retired), + ID(TOPDOWN_FETCH_BUBBLES, topdown-fetch-bubbles), + ID(TOPDOWN_RECOVERY_BUBBLES, topdown-recovery-bubbles), }; #undef ID diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h index 0150e786ccc7..c29bb94c48a4 100644 --- a/tools/perf/util/stat.h +++ b/tools/perf/util/stat.h @@ -17,6 +17,11 @@ enum perf_stat_evsel_id { PERF_STAT_EVSEL_ID__TRANSACTION_START, PERF_STAT_EVSEL_ID__ELISION_START, PERF_STAT_EVSEL_ID__CYCLES_IN_TX_CP, + PERF_STAT_EVSEL_ID__TOPDOWN_TOTAL_SLOTS, + PERF_STAT_EVSEL_ID__TOPDOWN_SLOTS_ISSUED, + PERF_STAT_EVSEL_ID__TOPDOWN_SLOTS_RETIRED, + PERF_STAT_EVSEL_ID__TOPDOWN_FETCH_BUBBLES, + PERF_STAT_EVSEL_ID__TOPDOWN_RECOVERY_BUBBLES, PERF_STAT_EVSEL_ID__MAX, }; |