diff options
Diffstat (limited to 'tools/perf/util/bpf_lock_contention.c')
| -rw-r--r-- | tools/perf/util/bpf_lock_contention.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/tools/perf/util/bpf_lock_contention.c b/tools/perf/util/bpf_lock_contention.c new file mode 100644 index 000000000000..c591a66733ef --- /dev/null +++ b/tools/perf/util/bpf_lock_contention.c @@ -0,0 +1,189 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "util/debug.h" +#include "util/evlist.h" +#include "util/machine.h" +#include "util/map.h" +#include "util/symbol.h" +#include "util/target.h" +#include "util/thread_map.h" +#include "util/lock-contention.h" +#include <linux/zalloc.h> +#include <bpf/bpf.h> + +#include "bpf_skel/lock_contention.skel.h" + +static struct lock_contention_bpf *skel; + +/* should be same as bpf_skel/lock_contention.bpf.c */ +struct lock_contention_key { + s32 stack_id; +}; + +struct lock_contention_data { + u64 total_time; + u64 min_time; + u64 max_time; + u32 count; + u32 flags; +}; + +int lock_contention_prepare(struct lock_contention *con) +{ + int i, fd; + int ncpus = 1, ntasks = 1; + struct evlist *evlist = con->evlist; + struct target *target = con->target; + + skel = lock_contention_bpf__open(); + if (!skel) { + pr_err("Failed to open lock-contention BPF skeleton\n"); + return -1; + } + + bpf_map__set_max_entries(skel->maps.stacks, con->map_nr_entries); + bpf_map__set_max_entries(skel->maps.lock_stat, con->map_nr_entries); + + if (target__has_cpu(target)) + ncpus = perf_cpu_map__nr(evlist->core.user_requested_cpus); + if (target__has_task(target)) + ntasks = perf_thread_map__nr(evlist->core.threads); + + bpf_map__set_max_entries(skel->maps.cpu_filter, ncpus); + bpf_map__set_max_entries(skel->maps.task_filter, ntasks); + + if (lock_contention_bpf__load(skel) < 0) { + pr_err("Failed to load lock-contention BPF skeleton\n"); + return -1; + } + + if (target__has_cpu(target)) { + 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__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 (target__none(target) && evlist->workload.pid > 0) { + u32 pid = evlist->workload.pid; + u8 val = 1; + + skel->bss->has_task = 1; + fd = bpf_map__fd(skel->maps.task_filter); + bpf_map_update_elem(fd, &pid, &val, BPF_ANY); + } + + lock_contention_bpf__attach(skel); + return 0; +} + +int lock_contention_start(void) +{ + skel->bss->enabled = 1; + return 0; +} + +int lock_contention_stop(void) +{ + skel->bss->enabled = 0; + return 0; +} + +int lock_contention_read(struct lock_contention *con) +{ + int fd, stack; + s32 prev_key, key; + struct lock_contention_data data; + struct lock_stat *st; + struct machine *machine = con->machine; + u64 stack_trace[CONTENTION_STACK_DEPTH]; + + fd = bpf_map__fd(skel->maps.lock_stat); + stack = bpf_map__fd(skel->maps.stacks); + + con->lost = skel->bss->lost; + + prev_key = 0; + while (!bpf_map_get_next_key(fd, &prev_key, &key)) { + struct map *kmap; + struct symbol *sym; + int idx; + + bpf_map_lookup_elem(fd, &key, &data); + st = zalloc(sizeof(*st)); + if (st == NULL) + return -1; + + st->nr_contended = data.count; + st->wait_time_total = data.total_time; + st->wait_time_max = data.max_time; + st->wait_time_min = data.min_time; + + if (data.count) + st->avg_wait_time = data.total_time / data.count; + + st->flags = data.flags; + + bpf_map_lookup_elem(stack, &key, stack_trace); + + /* skip BPF + lock internal functions */ + idx = CONTENTION_STACK_SKIP; + while (is_lock_function(machine, stack_trace[idx]) && + idx < CONTENTION_STACK_DEPTH - 1) + idx++; + + st->addr = stack_trace[idx]; + sym = machine__find_kernel_symbol(machine, st->addr, &kmap); + + if (sym) { + unsigned long offset; + int ret = 0; + + offset = kmap->map_ip(kmap, st->addr) - sym->start; + + if (offset) + ret = asprintf(&st->name, "%s+%#lx", sym->name, offset); + else + st->name = strdup(sym->name); + + if (ret < 0 || st->name == NULL) + return -1; + } else if (asprintf(&st->name, "%#lx", (unsigned long)st->addr) < 0) { + free(st); + return -1; + } + + hlist_add_head(&st->hash_entry, con->result); + prev_key = key; + } + + return 0; +} + +int lock_contention_finish(void) +{ + if (skel) { + skel->bss->enabled = 0; + lock_contention_bpf__destroy(skel); + } + + return 0; +} |