diff options
author | Namhyung Kim <namhyung@kernel.org> | 2023-02-02 18:13:22 -0800 |
---|---|---|
committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2023-02-03 17:12:26 -0300 |
commit | 492fef218a6606c53bbb979a65b8f827c5ea02ce (patch) | |
tree | 59a84f8ba0a133eb153a812ecd95d9c19a83fc96 /tools/perf | |
parent | 7105311c2d3bce8f52653dbfe87de475a251892b (diff) | |
download | lwn-492fef218a6606c53bbb979a65b8f827c5ea02ce.tar.gz lwn-492fef218a6606c53bbb979a65b8f827c5ea02ce.zip |
perf lock contention: Factor out lock_contention_get_name()
The lock_contention_get_name() returns a name for the lock stat entry
based on the current aggregation mode. As it's called sequentially in a
single thread, it can return the address of a static buffer for symbol
and offset of the caller.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230203021324.143540-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf')
-rw-r--r-- | tools/perf/util/bpf_lock_contention.c | 115 |
1 files changed, 65 insertions, 50 deletions
diff --git a/tools/perf/util/bpf_lock_contention.c b/tools/perf/util/bpf_lock_contention.c index 4902ac331f41..286e52ba9f91 100644 --- a/tools/perf/util/bpf_lock_contention.c +++ b/tools/perf/util/bpf_lock_contention.c @@ -163,9 +163,70 @@ int lock_contention_stop(void) return 0; } +static const char *lock_contention_get_name(struct lock_contention *con, + struct contention_key *key, + u64 *stack_trace) +{ + int idx = 0; + u64 addr; + const char *name = ""; + static char name_buf[KSYM_NAME_LEN]; + struct symbol *sym; + struct map *kmap; + struct machine *machine = con->machine; + + if (con->aggr_mode == LOCK_AGGR_TASK) { + struct contention_task_data task; + int pid = key->aggr_key; + int task_fd = bpf_map__fd(skel->maps.task_data); + + /* do not update idle comm which contains CPU number */ + if (pid) { + struct thread *t = __machine__findnew_thread(machine, /*pid=*/-1, pid); + + if (t == NULL) + return name; + if (!bpf_map_lookup_elem(task_fd, &pid, &task) && + thread__set_comm(t, task.comm, /*timestamp=*/0)) + name = task.comm; + } + return name; + } + + if (con->aggr_mode == LOCK_AGGR_ADDR) { + sym = machine__find_kernel_symbol(machine, key->aggr_key, &kmap); + if (sym) + name = sym->name; + return name; + } + + /* LOCK_AGGR_CALLER: skip lock internal functions */ + while (machine__is_lock_function(machine, stack_trace[idx]) && + idx < con->max_stack - 1) + idx++; + + addr = stack_trace[idx]; + sym = machine__find_kernel_symbol(machine, addr, &kmap); + + if (sym) { + unsigned long offset; + + offset = kmap->map_ip(kmap, addr) - sym->start; + + if (offset == 0) + return sym->name; + + snprintf(name_buf, sizeof(name_buf), "%s+%#lx", sym->name, offset); + } else { + snprintf(name_buf, sizeof(name_buf), "%#lx", (unsigned long)addr); + } + + return name_buf; +} + int lock_contention_read(struct lock_contention *con) { - int fd, stack, task_fd, err = 0; + int fd, stack, err = 0; struct contention_key *prev_key, key; struct contention_data data = {}; struct lock_stat *st = NULL; @@ -175,7 +236,6 @@ int lock_contention_read(struct lock_contention *con) fd = bpf_map__fd(skel->maps.lock_stat); stack = bpf_map__fd(skel->maps.stacks); - task_fd = bpf_map__fd(skel->maps.task_data); con->lost = skel->bss->lost; @@ -195,9 +255,6 @@ int lock_contention_read(struct lock_contention *con) prev_key = NULL; while (!bpf_map_get_next_key(fd, prev_key, &key)) { - struct map *kmap; - struct symbol *sym; - int idx = 0; s32 stack_id; /* to handle errors in the loop body */ @@ -219,61 +276,19 @@ int lock_contention_read(struct lock_contention *con) st->flags = data.flags; st->addr = key.aggr_key; - if (con->aggr_mode == LOCK_AGGR_TASK) { - struct contention_task_data task; - struct thread *t; - int pid = key.aggr_key; - - /* do not update idle comm which contains CPU number */ - if (st->addr) { - bpf_map_lookup_elem(task_fd, &pid, &task); - t = __machine__findnew_thread(machine, /*pid=*/-1, pid); - thread__set_comm(t, task.comm, /*timestamp=*/0); - } - goto next; - } - - if (con->aggr_mode == LOCK_AGGR_ADDR) { - sym = machine__find_kernel_symbol(machine, st->addr, &kmap); - if (sym) - st->name = strdup(sym->name); - goto next; - } - stack_id = key.aggr_key; bpf_map_lookup_elem(stack, &stack_id, stack_trace); - /* skip lock internal functions */ - while (machine__is_lock_function(machine, stack_trace[idx]) && - idx < con->max_stack - 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) - break; - } else if (asprintf(&st->name, "%#lx", (unsigned long)st->addr) < 0) { + st->name = strdup(lock_contention_get_name(con, &key, stack_trace)); + if (st->name == NULL) break; - } if (con->save_callstack) { st->callstack = memdup(stack_trace, stack_size); if (st->callstack == NULL) break; } -next: + hlist_add_head(&st->hash_entry, con->result); prev_key = &key; |