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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /tools/perf/util/bpf_off_cpu.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/perf/util/bpf_off_cpu.c')
-rw-r--r-- | tools/perf/util/bpf_off_cpu.c | 393 |
1 files changed, 393 insertions, 0 deletions
diff --git a/tools/perf/util/bpf_off_cpu.c b/tools/perf/util/bpf_off_cpu.c new file mode 100644 index 0000000000..21f4d9ba02 --- /dev/null +++ b/tools/perf/util/bpf_off_cpu.c @@ -0,0 +1,393 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "util/bpf_counter.h" +#include "util/debug.h" +#include "util/evsel.h" +#include "util/evlist.h" +#include "util/off_cpu.h" +#include "util/perf-hooks.h" +#include "util/record.h" +#include "util/session.h" +#include "util/target.h" +#include "util/cpumap.h" +#include "util/thread_map.h" +#include "util/cgroup.h" +#include "util/strlist.h" +#include <bpf/bpf.h> + +#include "bpf_skel/off_cpu.skel.h" + +#define MAX_STACKS 32 +#define MAX_PROC 4096 +/* we don't need actual timestamp, just want to put the samples at last */ +#define OFF_CPU_TIMESTAMP (~0ull << 32) + +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; + + /* update task filter for the given workload */ + if (!skel->bss->has_cpu && !skel->bss->has_task && + perf_thread_map__pid(evlist->core.threads, 0) != -1) { + int fd; + u32 pid; + u8 val = 1; + + skel->bss->has_task = 1; + skel->bss->uses_tgid = 1; + fd = bpf_map__fd(skel->maps.task_filter); + pid = perf_thread_map__pid(evlist->core.threads, 0); + bpf_map_update_elem(fd, &pid, &val, BPF_ANY); + } + + skel->bss->enabled = 1; +} + +static void off_cpu_finish(void *arg __maybe_unused) +{ + skel->bss->enabled = 0; + off_cpu_bpf__destroy(skel); +} + +/* v5.18 kernel added prev_state arg, so it needs to check the signature */ +static void check_sched_switch_args(void) +{ + const struct btf *btf = btf__load_vmlinux_btf(); + const struct btf_type *t1, *t2, *t3; + u32 type_id; + + type_id = btf__find_by_name_kind(btf, "btf_trace_sched_switch", + BTF_KIND_TYPEDEF); + if ((s32)type_id < 0) + return; + + t1 = btf__type_by_id(btf, type_id); + if (t1 == NULL) + return; + + t2 = btf__type_by_id(btf, t1->type); + if (t2 == NULL || !btf_is_ptr(t2)) + return; + + t3 = btf__type_by_id(btf, t2->type); + /* btf_trace func proto has one more argument for the context */ + if (t3 && btf_is_func_proto(t3) && btf_vlen(t3) == 5) { + /* new format: pass prev_state as 4th arg */ + skel->rodata->has_prev_state = true; + } +} + +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; + 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; + } + + skel = off_cpu_bpf__open(); + if (!skel) { + pr_err("Failed to open off-cpu BPF skeleton\n"); + return -1; + } + + /* don't need to set cpu filter for system-wide mode */ + if (target->cpu_list) { + ncpus = perf_cpu_map__nr(evlist->core.user_requested_cpus); + bpf_map__set_max_entries(skel->maps.cpu_filter, ncpus); + } + + if (target->pid) { + pid_slist = strlist__new(target->pid, NULL); + if (!pid_slist) { + pr_err("Failed to create a strlist for pid\n"); + return -1; + } + + ntasks = 0; + strlist__for_each_entry(pos, pid_slist) { + char *end_ptr; + int pid = strtol(pos->s, &end_ptr, 10); + + if (pid == INT_MIN || pid == INT_MAX || + (*end_ptr != '\0' && *end_ptr != ',')) + continue; + + ntasks++; + } + + if (ntasks < MAX_PROC) + ntasks = MAX_PROC; + + bpf_map__set_max_entries(skel->maps.task_filter, ntasks); + } else if (target__has_task(target)) { + ntasks = perf_thread_map__nr(evlist->core.threads); + bpf_map__set_max_entries(skel->maps.task_filter, ntasks); + } else if (target__none(target)) { + bpf_map__set_max_entries(skel->maps.task_filter, MAX_PROC); + } + + if (evlist__first(evlist)->cgrp) { + ncgrps = evlist->core.nr_entries - 1; /* excluding a dummy */ + bpf_map__set_max_entries(skel->maps.cgroup_filter, ncgrps); + + if (!cgroup_is_v2("perf_event")) + skel->rodata->uses_cgroup_v1 = true; + } + + if (opts->record_cgroup) { + skel->rodata->needs_cgroup = true; + + if (!cgroup_is_v2("perf_event")) + skel->rodata->uses_cgroup_v1 = true; + } + + set_max_rlimit(); + check_sched_switch_args(); + + err = off_cpu_bpf__load(skel); + if (err) { + pr_err("Failed to load off-cpu skeleton\n"); + goto out; + } + + if (target->cpu_list) { + u32 cpu; + u8 val = 1; + + skel->bss->has_cpu = 1; + fd = bpf_map__fd(skel->maps.cpu_filter); + + for (i = 0; i < ncpus; i++) { + cpu = perf_cpu_map__cpu(evlist->core.user_requested_cpus, i).cpu; + bpf_map_update_elem(fd, &cpu, &val, BPF_ANY); + } + } + + if (target->pid) { + u8 val = 1; + + skel->bss->has_task = 1; + skel->bss->uses_tgid = 1; + fd = bpf_map__fd(skel->maps.task_filter); + + strlist__for_each_entry(pos, pid_slist) { + char *end_ptr; + u32 tgid; + int pid = strtol(pos->s, &end_ptr, 10); + + if (pid == INT_MIN || pid == INT_MAX || + (*end_ptr != '\0' && *end_ptr != ',')) + continue; + + tgid = pid; + bpf_map_update_elem(fd, &tgid, &val, BPF_ANY); + } + } else if (target__has_task(target)) { + u32 pid; + u8 val = 1; + + skel->bss->has_task = 1; + fd = bpf_map__fd(skel->maps.task_filter); + + for (i = 0; i < ntasks; i++) { + pid = perf_thread_map__pid(evlist->core.threads, i); + bpf_map_update_elem(fd, &pid, &val, BPF_ANY); + } + } + + if (evlist__first(evlist)->cgrp) { + struct evsel *evsel; + u8 val = 1; + + skel->bss->has_cgroup = 1; + fd = bpf_map__fd(skel->maps.cgroup_filter); + + evlist__for_each_entry(evlist, evsel) { + struct cgroup *cgrp = evsel->cgrp; + + if (cgrp == NULL) + continue; + + if (!cgrp->id && read_cgroup_id(cgrp) < 0) { + pr_err("Failed to read cgroup id of %s\n", + cgrp->name); + goto out; + } + + bpf_map_update_elem(fd, &cgrp->id, &val, BPF_ANY); + } + } + + err = off_cpu_bpf__attach(skel); + if (err) { + pr_err("Failed to attach off-cpu BPF skeleton\n"); + goto out; + } + + if (perf_hooks__set_hook("record_start", off_cpu_start, evlist) || + perf_hooks__set_hook("record_end", off_cpu_finish, evlist)) { + pr_err("Failed to attach off-cpu skeleton\n"); + goto out; + } + + return 0; + +out: + off_cpu_bpf__destroy(skel); + return -1; +} + +int off_cpu_write(struct perf_session *session) +{ + int bytes = 0, size; + int fd, stack; + u64 sample_type, val, sid = 0; + 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); + 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]; + } + + fd = bpf_map__fd(skel->maps.off_cpu); + stack = bpf_map__fd(skel->maps.stacks); + memset(&prev, 0, sizeof(prev)); + + while (!bpf_map_get_next_key(fd, &prev, &key)) { + int n = 1; /* start from perf_event_header */ + int ip_pos = -1; + + bpf_map_lookup_elem(fd, &key, &val); + + 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; + + size = n * sizeof(u64); + data.hdr.size = size; + bytes += size; + + if (perf_data_file__write(file, &data, size) < 0) { + pr_err("failed to write perf data, error: %m\n"); + return bytes; + } + + prev = key; + /* increase dummy timestamp to sort later samples */ + tstamp++; + } + return bytes; +} |