diff options
| -rw-r--r-- | tools/tracing/rtla/.gitignore | 1 | ||||
| -rw-r--r-- | tools/tracing/rtla/Makefile | 14 | ||||
| -rw-r--r-- | tools/tracing/rtla/src/Build | 1 | ||||
| -rw-r--r-- | tools/tracing/rtla/src/timerlat.bpf.c | 149 | ||||
| -rw-r--r-- | tools/tracing/rtla/src/timerlat_bpf.c | 166 | ||||
| -rw-r--r-- | tools/tracing/rtla/src/timerlat_bpf.h | 59 |
6 files changed, 389 insertions, 1 deletions
diff --git a/tools/tracing/rtla/.gitignore b/tools/tracing/rtla/.gitignore index 293f0dbb0ca2..1a394ad26cc1 100644 --- a/tools/tracing/rtla/.gitignore +++ b/tools/tracing/rtla/.gitignore @@ -4,3 +4,4 @@ rtla-static fixdep feature FEATURE-DUMP +*.skel.h diff --git a/tools/tracing/rtla/Makefile b/tools/tracing/rtla/Makefile index 0aa116f7b355..557af322be61 100644 --- a/tools/tracing/rtla/Makefile +++ b/tools/tracing/rtla/Makefile @@ -73,6 +73,17 @@ CFLAGS += $(INCLUDES) $(LIB_INCLUDES) export CFLAGS OUTPUT srctree +ifeq ($(BUILD_BPF_SKEL),1) +src/timerlat.bpf.o: src/timerlat.bpf.c + $(QUIET_CLANG)$(CLANG) -g -O2 -target bpf -c $(filter %.c,$^) -o $@ + +src/timerlat.skel.h: src/timerlat.bpf.o + $(QUIET_GENSKEL)$(BPFTOOL) gen skeleton $< > $@ +else +src/timerlat.skel.h: + $(Q)echo '/* BPF skeleton is disabled */' > src/timerlat.skel.h +endif + $(RTLA): $(RTLA_IN) $(QUIET_LINK)$(CC) $(LDFLAGS) -o $(RTLA) $(RTLA_IN) $(EXTLIBS) @@ -83,7 +94,7 @@ static: $(RTLA_IN) rtla.%: fixdep FORCE make -f $(srctree)/tools/build/Makefile.build dir=. $@ -$(RTLA_IN): fixdep FORCE +$(RTLA_IN): fixdep FORCE src/timerlat.skel.h make $(build)=rtla clean: doc_clean fixdep-clean @@ -91,6 +102,7 @@ clean: doc_clean fixdep-clean $(Q)find . -name '*.o' -delete -o -name '\.*.cmd' -delete -o -name '\.*.d' -delete $(Q)rm -f rtla rtla-static fixdep FEATURE-DUMP rtla-* $(Q)rm -rf feature + $(Q)rm -f src/timerlat.bpf.o src/timerlat.skel.h check: $(RTLA) RTLA=$(RTLA) prove -o -f tests/ .PHONY: FORCE clean check diff --git a/tools/tracing/rtla/src/Build b/tools/tracing/rtla/src/Build index dbed9e31829b..7bb7e39e391a 100644 --- a/tools/tracing/rtla/src/Build +++ b/tools/tracing/rtla/src/Build @@ -8,4 +8,5 @@ rtla-y += timerlat_top.o rtla-y += timerlat_hist.o rtla-y += timerlat_u.o rtla-y += timerlat_aa.o +rtla-y += timerlat_bpf.o rtla-y += rtla.o diff --git a/tools/tracing/rtla/src/timerlat.bpf.c b/tools/tracing/rtla/src/timerlat.bpf.c new file mode 100644 index 000000000000..96196d46e170 --- /dev/null +++ b/tools/tracing/rtla/src/timerlat.bpf.c @@ -0,0 +1,149 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/bpf.h> +#include <bpf/bpf_tracing.h> +#include <stdbool.h> +#include "timerlat_bpf.h" + +#define nosubprog __always_inline +#define MAX_ENTRIES_DEFAULT 4096 + +char LICENSE[] SEC("license") = "GPL"; + +struct trace_event_raw_timerlat_sample { + unsigned long long timer_latency; + int context; +} __attribute__((preserve_access_index)); + +struct { + __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); + __uint(max_entries, MAX_ENTRIES_DEFAULT); + __type(key, unsigned int); + __type(value, unsigned long long); +} hist_irq SEC(".maps"), hist_thread SEC(".maps"), hist_user SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); + __uint(max_entries, SUMMARY_FIELD_N); + __type(key, unsigned int); + __type(value, unsigned long long); +} summary_irq SEC(".maps"), summary_thread SEC(".maps"), summary_user SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_RINGBUF); + __uint(max_entries, 1); +} signal_stop_tracing SEC(".maps"); + +/* Params to be set by rtla */ +const volatile int bucket_size = 1; +const volatile int output_divisor = 1000; +const volatile int entries = 256; +const volatile int irq_threshold; +const volatile int thread_threshold; +const volatile bool aa_only; + +int stop_tracing; + +nosubprog unsigned long long map_get(void *map, + unsigned int key) +{ + unsigned long long *value_ptr; + + value_ptr = bpf_map_lookup_elem(map, &key); + + return !value_ptr ? 0 : *value_ptr; +} + +nosubprog void map_set(void *map, + unsigned int key, + unsigned long long value) +{ + bpf_map_update_elem(map, &key, &value, BPF_ANY); +} + +nosubprog void map_increment(void *map, + unsigned int key) +{ + map_set(map, key, map_get(map, key) + 1); +} + +nosubprog void update_main_hist(void *map, + int bucket) +{ + if (entries == 0) + /* No histogram */ + return; + + if (bucket >= entries) + /* Overflow */ + return; + + map_increment(map, bucket); +} + +nosubprog void update_summary(void *map, + unsigned long long latency, + int bucket) +{ + if (aa_only) + /* Auto-analysis only, nothing to be done here */ + return; + + map_set(map, SUMMARY_CURRENT, latency); + + if (bucket >= entries) + /* Overflow */ + map_increment(map, SUMMARY_OVERFLOW); + + if (latency > map_get(map, SUMMARY_MAX)) + map_set(map, SUMMARY_MAX, latency); + + if (latency < map_get(map, SUMMARY_MIN) || map_get(map, SUMMARY_COUNT) == 0) + map_set(map, SUMMARY_MIN, latency); + + map_increment(map, SUMMARY_COUNT); + map_set(map, SUMMARY_SUM, map_get(map, SUMMARY_SUM) + latency); +} + +nosubprog void set_stop_tracing(void) +{ + int value = 0; + + /* Suppress further sample processing */ + stop_tracing = 1; + + /* Signal to userspace */ + bpf_ringbuf_output(&signal_stop_tracing, &value, sizeof(value), 0); +} + +SEC("tp/osnoise/timerlat_sample") +int handle_timerlat_sample(struct trace_event_raw_timerlat_sample *tp_args) +{ + unsigned long long latency, latency_us; + int bucket; + + if (stop_tracing) + return 0; + + latency = tp_args->timer_latency / output_divisor; + latency_us = tp_args->timer_latency / 1000; + bucket = latency / bucket_size; + + if (tp_args->context == 0) { + update_main_hist(&hist_irq, bucket); + update_summary(&summary_irq, latency, bucket); + + if (irq_threshold != 0 && latency_us >= irq_threshold) + set_stop_tracing(); + } else if (tp_args->context == 1) { + update_main_hist(&hist_thread, bucket); + update_summary(&summary_thread, latency, bucket); + + if (thread_threshold != 0 && latency_us >= thread_threshold) + set_stop_tracing(); + } else { + update_main_hist(&hist_user, bucket); + update_summary(&summary_user, latency, bucket); + } + + return 0; +} diff --git a/tools/tracing/rtla/src/timerlat_bpf.c b/tools/tracing/rtla/src/timerlat_bpf.c new file mode 100644 index 000000000000..5abee884037a --- /dev/null +++ b/tools/tracing/rtla/src/timerlat_bpf.c @@ -0,0 +1,166 @@ +// SPDX-License-Identifier: GPL-2.0 +#ifdef HAVE_BPF_SKEL +#include "timerlat.h" +#include "timerlat_bpf.h" +#include "timerlat.skel.h" + +static struct timerlat_bpf *bpf; + +/* + * timerlat_bpf_init - load and initialize BPF program to collect timerlat data + */ +int timerlat_bpf_init(struct timerlat_params *params) +{ + int err; + + debug_msg("Loading BPF program\n"); + + bpf = timerlat_bpf__open(); + if (!bpf) + return 1; + + /* Pass common options */ + bpf->rodata->output_divisor = params->output_divisor; + bpf->rodata->entries = params->entries; + bpf->rodata->irq_threshold = params->stop_us; + bpf->rodata->thread_threshold = params->stop_total_us; + bpf->rodata->aa_only = params->aa_only; + + if (params->entries != 0) { + /* Pass histogram options */ + bpf->rodata->bucket_size = params->bucket_size; + + /* Set histogram array sizes */ + bpf_map__set_max_entries(bpf->maps.hist_irq, params->entries); + bpf_map__set_max_entries(bpf->maps.hist_thread, params->entries); + bpf_map__set_max_entries(bpf->maps.hist_user, params->entries); + } else { + /* No entries, disable histogram */ + bpf_map__set_autocreate(bpf->maps.hist_irq, false); + bpf_map__set_autocreate(bpf->maps.hist_thread, false); + bpf_map__set_autocreate(bpf->maps.hist_user, false); + } + + if (params->aa_only) { + /* Auto-analysis only, disable summary */ + bpf_map__set_autocreate(bpf->maps.summary_irq, false); + bpf_map__set_autocreate(bpf->maps.summary_thread, false); + bpf_map__set_autocreate(bpf->maps.summary_user, false); + } + + /* Load and verify BPF program */ + err = timerlat_bpf__load(bpf); + if (err) { + timerlat_bpf__destroy(bpf); + return err; + } + + return 0; +} + +/* + * timerlat_bpf_attach - attach BPF program to collect timerlat data + */ +int timerlat_bpf_attach(void) +{ + debug_msg("Attaching BPF program\n"); + + return timerlat_bpf__attach(bpf); +} + +/* + * timerlat_bpf_detach - detach BPF program to collect timerlat data + */ +void timerlat_bpf_detach(void) +{ + timerlat_bpf__detach(bpf); +} + +/* + * timerlat_bpf_detach - destroy BPF program to collect timerlat data + */ +void timerlat_bpf_destroy(void) +{ + timerlat_bpf__destroy(bpf); +} + +static int handle_rb_event(void *ctx, void *data, size_t data_sz) +{ + return 0; +} + +/* + * timerlat_bpf_wait - wait until tracing is stopped or signal + */ +int timerlat_bpf_wait(int timeout) +{ + struct ring_buffer *rb; + int retval; + + rb = ring_buffer__new(bpf_map__fd(bpf->maps.signal_stop_tracing), + handle_rb_event, NULL, NULL); + retval = ring_buffer__poll(rb, timeout * 1000); + ring_buffer__free(rb); + + return retval; +} + +static int get_value(struct bpf_map *map_irq, + struct bpf_map *map_thread, + struct bpf_map *map_user, + int key, + long long *value_irq, + long long *value_thread, + long long *value_user, + int cpus) +{ + int err; + + err = bpf_map__lookup_elem(map_irq, &key, + sizeof(unsigned int), value_irq, + sizeof(long long) * cpus, 0); + if (err) + return err; + err = bpf_map__lookup_elem(map_thread, &key, + sizeof(unsigned int), value_thread, + sizeof(long long) * cpus, 0); + if (err) + return err; + err = bpf_map__lookup_elem(map_user, &key, + sizeof(unsigned int), value_user, + sizeof(long long) * cpus, 0); + if (err) + return err; + return 0; +} + +/* + * timerlat_bpf_get_hist_value - get value from BPF hist map + */ +int timerlat_bpf_get_hist_value(int key, + long long *value_irq, + long long *value_thread, + long long *value_user, + int cpus) +{ + return get_value(bpf->maps.hist_irq, + bpf->maps.hist_thread, + bpf->maps.hist_user, + key, value_irq, value_thread, value_user, cpus); +} + +/* + * timerlat_bpf_get_summary_value - get value from BPF summary map + */ +int timerlat_bpf_get_summary_value(enum summary_field key, + long long *value_irq, + long long *value_thread, + long long *value_user, + int cpus) +{ + return get_value(bpf->maps.summary_irq, + bpf->maps.summary_thread, + bpf->maps.summary_user, + key, value_irq, value_thread, value_user, cpus); +} +#endif /* HAVE_BPF_SKEL */ diff --git a/tools/tracing/rtla/src/timerlat_bpf.h b/tools/tracing/rtla/src/timerlat_bpf.h new file mode 100644 index 000000000000..f1b54dbddb0e --- /dev/null +++ b/tools/tracing/rtla/src/timerlat_bpf.h @@ -0,0 +1,59 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#pragma once + +enum summary_field { + SUMMARY_CURRENT, + SUMMARY_MIN, + SUMMARY_MAX, + SUMMARY_COUNT, + SUMMARY_SUM, + SUMMARY_OVERFLOW, + SUMMARY_FIELD_N +}; + +#ifndef __bpf__ +#ifdef HAVE_BPF_SKEL +int timerlat_bpf_init(struct timerlat_params *params); +int timerlat_bpf_attach(void); +void timerlat_bpf_detach(void); +void timerlat_bpf_destroy(void); +int timerlat_bpf_wait(int timeout); +int timerlat_bpf_get_hist_value(int key, + long long *value_irq, + long long *value_thread, + long long *value_user, + int cpus); +int timerlat_bpf_get_summary_value(enum summary_field key, + long long *value_irq, + long long *value_thread, + long long *value_user, + int cpus); +static inline int have_libbpf_support(void) { return 1; } +#else +static inline int timerlat_bpf_init(struct timerlat_params *params) +{ + return -1; +} +static inline int timerlat_bpf_attach(void) { return -1; } +static inline void timerlat_bpf_detach(void) { }; +static inline void timerlat_bpf_destroy(void) { }; +static inline int timerlat_bpf_wait(int timeout) { return -1; } +static inline int timerlat_bpf_get_hist_value(int key, + long long *value_irq, + long long *value_thread, + long long *value_user, + int cpus) +{ + return -1; +} +static inline int timerlat_bpf_get_summary_value(enum summary_field key, + long long *value_irq, + long long *value_thread, + long long *value_user, + int cpus) +{ + return -1; +} +static inline int have_libbpf_support(void) { return 0; } +#endif /* HAVE_BPF_SKEL */ +#endif /* __bpf__ */ |