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In off_cpu_strip, we read events one by one, stripping actual samples from raw data. After stripping is done, a stripped buffer will be written to the perf.data(or compressed). The size is end - start without masking, because masking will be handled by perf_mmap__read_event(). Also, there's no need to call perf_mmap__consume() as it will be called in perf_mmap__push(). We read all the data at once, so start will be moved to end, when perf_mmap__push() is called in pushfn the second time, size will be zero, just returns directly. Hook record_done instead of record_end to off_cpu_finish. Although moving record_end hook is also fine because currently, only off-cpu is using these hooks, technically record doesn't end when we need to turn off BPF output, so it may confuse if moved. The reason why there's an additional off_cpu_change_type is that it cannot be put into off_cpu_finish because there are still samples to be read(which requires sample_type to stay PERF_SAMPLE_RAW), and it cannot be hooked to record_end because it has to be put before record__finish_output. Signed-off-by: Howard Chu --- tools/perf/util/bpf_off_cpu.c | 245 +++++++++++++----------------- tools/perf/util/off_cpu.h | 14 +- tools/perf/util/perf-hooks-list.h | 1 + 3 files changed, 121 insertions(+), 139 deletions(-) diff --git a/tools/perf/util/bpf_off_cpu.c b/tools/perf/util/bpf_off_cpu.c index 6af36142dc5a..df1f02938099 100644 --- a/tools/perf/util/bpf_off_cpu.c +++ b/tools/perf/util/bpf_off_cpu.c @@ -12,6 +12,9 @@ #include "util/thread_map.h" #include "util/cgroup.h" #include "util/strlist.h" +#include "util/mmap.h" +#include "util/sample.h" +#include #include #include "bpf_skel/off_cpu.skel.h" @@ -23,51 +26,6 @@ static struct off_cpu_bpf *skel; -struct off_cpu_key { - u32 pid; - u32 tgid; - u32 stack_id; - u32 state; - u64 cgroup_id; -}; - -union off_cpu_data { - struct perf_event_header hdr; - u64 array[1024 / sizeof(u64)]; -}; - -static int off_cpu_config(struct evlist *evlist) -{ - struct evsel *evsel; - struct perf_event_attr attr = { - .type = PERF_TYPE_SOFTWARE, - .config = PERF_COUNT_SW_BPF_OUTPUT, - .size = sizeof(attr), /* to capture ABI version */ - }; - char *evname = strdup(OFFCPU_EVENT); - - if (evname == NULL) - return -ENOMEM; - - evsel = evsel__new(&attr); - if (!evsel) { - free(evname); - return -ENOMEM; - } - - evsel->core.attr.freq = 1; - evsel->core.attr.sample_period = 1; - /* off-cpu analysis depends on stack trace */ - evsel->core.attr.sample_type = PERF_SAMPLE_CALLCHAIN; - - evlist__add(evlist, evsel); - - free(evsel->name); - evsel->name = evname; - - return 0; -} - static void off_cpu_start(void *arg) { struct evlist *evlist = arg; @@ -125,18 +83,29 @@ static void check_sched_switch_args(void) btf__free(btf); } +int off_cpu_change_type(struct evlist *evlist) +{ + struct evsel *evsel; + + evsel = evlist__find_evsel_by_str(evlist, OFFCPU_EVENT); + if (evsel == NULL) + return -1; + + evsel->core.attr.sample_type = OFFCPU_SAMPLE_TYPES; + + return 0; +} + int off_cpu_prepare(struct evlist *evlist, struct target *target, struct record_opts *opts) { int err, fd, i; int ncpus = 1, ntasks = 1, ncgrps = 1; + u64 sid = 0; struct strlist *pid_slist = NULL; struct str_node *pos; - - if (off_cpu_config(evlist) < 0) { - pr_err("Failed to config off-cpu BPF event\n"); - return -1; - } + struct evsel *evsel; + struct perf_cpu pcpu; skel = off_cpu_bpf__open(); if (!skel) { @@ -250,7 +219,6 @@ int off_cpu_prepare(struct evlist *evlist, struct target *target, } if (evlist__first(evlist)->cgrp) { - struct evsel *evsel; u8 val = 1; skel->bss->has_cgroup = 1; @@ -272,6 +240,25 @@ int off_cpu_prepare(struct evlist *evlist, struct target *target, } } + evsel = evlist__find_evsel_by_str(evlist, OFFCPU_EVENT); + if (evsel == NULL) { + pr_err("%s evsel not found\n", OFFCPU_EVENT); + goto out; + } + + if (evsel->core.id) + sid = evsel->core.id[0]; + + skel->bss->sample_id = sid; + skel->bss->sample_type = OFFCPU_SAMPLE_TYPES; + + perf_cpu_map__for_each_cpu(pcpu, i, evsel->core.cpus) { + bpf_map__update_elem(skel->maps.offcpu_output, + &pcpu.cpu, sizeof(int), + xyarray__entry(evsel->core.fd, pcpu.cpu, 0), + sizeof(__u32), BPF_ANY); + } + err = off_cpu_bpf__attach(skel); if (err) { pr_err("Failed to attach off-cpu BPF skeleton\n"); @@ -279,7 +266,7 @@ int off_cpu_prepare(struct evlist *evlist, struct target *target, } if (perf_hooks__set_hook("record_start", off_cpu_start, evlist) || - perf_hooks__set_hook("record_end", off_cpu_finish, evlist)) { + perf_hooks__set_hook("record_done", off_cpu_finish, evlist)) { pr_err("Failed to attach off-cpu skeleton\n"); goto out; } @@ -291,105 +278,91 @@ int off_cpu_prepare(struct evlist *evlist, struct target *target, return -1; } -int off_cpu_write(struct perf_session *session) +ssize_t off_cpu_strip(struct evlist *evlist, struct mmap *mp, char *dst, size_t size) { - int bytes = 0, size; - int fd, stack; - u64 sample_type, val, sid = 0; + /* + * In this function, we read events one by one, + * stripping actual samples from raw data. + * The size is end - start without masking, + * because masking will be handled by + * perf_mmap__read_event() + */ + + union perf_event *event, tmp; + u64 sample_type = OFFCPU_SAMPLE_TYPES; + size_t written = 0, event_sz, write_sz, raw_sz_aligned, offset = 0; + void *src; + int err = 0, n = 0; + struct perf_sample sample; struct evsel *evsel; - struct perf_data_file *file = &session->data->file; - struct off_cpu_key prev, key; - union off_cpu_data data = { - .hdr = { - .type = PERF_RECORD_SAMPLE, - .misc = PERF_RECORD_MISC_USER, - }, - }; - u64 tstamp = OFF_CPU_TIMESTAMP; - - skel->bss->enabled = 0; - evsel = evlist__find_evsel_by_str(session->evlist, OFFCPU_EVENT); + evsel = evlist__find_evsel_by_str(evlist, OFFCPU_EVENT); if (evsel == NULL) { pr_err("%s evsel not found\n", OFFCPU_EVENT); - return 0; - } - - sample_type = evsel->core.attr.sample_type; - - if (sample_type & ~OFFCPU_SAMPLE_TYPES) { - pr_err("not supported sample type: %llx\n", - (unsigned long long)sample_type); return -1; } - if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER)) { - if (evsel->core.id) - sid = evsel->core.id[0]; - } + /* for writing sample time*/ + if (sample_type & PERF_SAMPLE_IDENTIFIER) + ++n; + if (sample_type & PERF_SAMPLE_IP) + ++n; + if (sample_type & PERF_SAMPLE_TID) + ++n; + + /* no need for perf_mmap__consume(), it will be handled by perf_mmap__push() */ + while ((event = perf_mmap__read_event(&mp->core)) != NULL) { + event_sz = event->header.size; + write_sz = event_sz; + src = event; + + if (event->header.type == PERF_RECORD_SAMPLE) { + err = evlist__parse_sample(evlist, event, &sample); + if (err) { + pr_err("Failed to parse off-cpu sample\n"); + return -1; + } - fd = bpf_map__fd(skel->maps.off_cpu); - stack = bpf_map__fd(skel->maps.stacks); - memset(&prev, 0, sizeof(prev)); + if (sample.raw_data && evsel->core.id) { + bool flag = false; - while (!bpf_map_get_next_key(fd, &prev, &key)) { - int n = 1; /* start from perf_event_header */ - int ip_pos = -1; + for (u32 i = 0; i < evsel->core.ids; i++) { + if (sample.id == evsel->core.id[i]) { + flag = true; + break; + } + } + if (flag) { + memcpy(&tmp, event, event_sz); - bpf_map_lookup_elem(fd, &key, &val); + /* raw data has extra bits for alignment, discard them */ + raw_sz_aligned = sample.raw_size - sizeof(u32); + memcpy(tmp.sample.array, sample.raw_data, raw_sz_aligned); - if (sample_type & PERF_SAMPLE_IDENTIFIER) - data.array[n++] = sid; - if (sample_type & PERF_SAMPLE_IP) { - ip_pos = n; - data.array[n++] = 0; /* will be updated */ - } - if (sample_type & PERF_SAMPLE_TID) - data.array[n++] = (u64)key.pid << 32 | key.tgid; - if (sample_type & PERF_SAMPLE_TIME) - data.array[n++] = tstamp; - if (sample_type & PERF_SAMPLE_ID) - data.array[n++] = sid; - if (sample_type & PERF_SAMPLE_CPU) - data.array[n++] = 0; - if (sample_type & PERF_SAMPLE_PERIOD) - data.array[n++] = val; - if (sample_type & PERF_SAMPLE_CALLCHAIN) { - int len = 0; - - /* data.array[n] is callchain->nr (updated later) */ - data.array[n + 1] = PERF_CONTEXT_USER; - data.array[n + 2] = 0; - - bpf_map_lookup_elem(stack, &key.stack_id, &data.array[n + 2]); - while (data.array[n + 2 + len]) - len++; - - /* update length of callchain */ - data.array[n] = len + 1; - - /* update sample ip with the first callchain entry */ - if (ip_pos >= 0) - data.array[ip_pos] = data.array[n + 2]; - - /* calculate sample callchain data array length */ - n += len + 2; - } - if (sample_type & PERF_SAMPLE_CGROUP) - data.array[n++] = key.cgroup_id; + write_sz = sizeof(struct perf_event_header) + + raw_sz_aligned; + + /* without this we'll have out of order events */ + if (sample_type & PERF_SAMPLE_TIME) + tmp.sample.array[n] = sample.time; - size = n * sizeof(u64); - data.hdr.size = size; - bytes += size; + tmp.header.size = write_sz; + tmp.header.type = PERF_RECORD_SAMPLE; + tmp.header.misc = PERF_RECORD_MISC_USER; - if (perf_data_file__write(file, &data, size) < 0) { - pr_err("failed to write perf data, error: %m\n"); - return bytes; + src = &tmp; + } + } } + if (offset + event_sz > size || written + write_sz > size) + break; - prev = key; - /* increase dummy timestamp to sort later samples */ - tstamp++; + memcpy(dst, src, write_sz); + + dst += write_sz; + written += write_sz; + offset += event_sz; } - return bytes; + + return written; } diff --git a/tools/perf/util/off_cpu.h b/tools/perf/util/off_cpu.h index 2dd67c60f211..03d2f29cbb47 100644 --- a/tools/perf/util/off_cpu.h +++ b/tools/perf/util/off_cpu.h @@ -20,7 +20,9 @@ struct record_opts; #ifdef HAVE_BPF_SKEL int off_cpu_prepare(struct evlist *evlist, struct target *target, struct record_opts *opts); -int off_cpu_write(struct perf_session *session); +ssize_t off_cpu_strip(struct evlist *evlist, struct mmap *mp, + char *dst, size_t size); +int off_cpu_change_type(struct evlist *evlist); #else static inline int off_cpu_prepare(struct evlist *evlist __maybe_unused, struct target *target __maybe_unused, @@ -28,8 +30,14 @@ static inline int off_cpu_prepare(struct evlist *evlist __maybe_unused, { return -1; } - -static inline int off_cpu_write(struct perf_session *session __maybe_unused) +static inline ssize_t off_cpu_strip(struct evlist *evlist __maybe_unused, + struct mmap *mp __maybe_unused, + char *dst __maybe_unused, + size_t size __maybe_unused) +{ + return -1; +} +static inline int off_cpu_change_type(struct evlist *evlist __maybe_unused) { return -1; } diff --git a/tools/perf/util/perf-hooks-list.h b/tools/perf/util/perf-hooks-list.h index 2867c07ee84e..1ce4d44ace35 100644 --- a/tools/perf/util/perf-hooks-list.h +++ b/tools/perf/util/perf-hooks-list.h @@ -1,3 +1,4 @@ PERF_HOOK(record_start) PERF_HOOK(record_end) +PERF_HOOK(record_done) PERF_HOOK(test)