From 688d2e8de231c54e289b640547af246343732348 Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Fri, 9 Dec 2022 11:07:26 -0800 Subject: [PATCH] perf lock contention: Add -l/--lock-addr option The -l/--lock-addr option is to implement per-lock-instance contention stat using LOCK_AGGR_ADDR. It displays lock address and optionally symbol name if exists. $ sudo ./perf lock con -abl sleep 1 contended total wait max wait avg wait address symbol 1 36.28 us 36.28 us 36.28 us ffff92615d6448b8 9 10.91 us 1.84 us 1.21 us ffffffffbaed50c0 rcu_state 1 10.49 us 10.49 us 10.49 us ffff9262ac4f0c80 8 4.68 us 1.67 us 585 ns ffffffffbae07a40 jiffies_lock 3 3.03 us 1.45 us 1.01 us ffff9262277861e0 1 924 ns 924 ns 924 ns ffff926095ba9d20 1 436 ns 436 ns 436 ns ffff9260bfda4f60 Signed-off-by: Namhyung Kim Cc: Adrian Hunter Cc: Blake Jones Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Song Liu Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20221209190727.759804-4-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-lock.txt | 4 ++ tools/perf/builtin-lock.c | 84 ++++++++++++++++++++------ tools/perf/util/bpf_lock_contention.c | 23 +++++-- tools/perf/util/bpf_skel/lock_contention.bpf.c | 17 ++++-- tools/perf/util/bpf_skel/lock_data.h | 2 +- 5 files changed, 102 insertions(+), 28 deletions(-) diff --git a/tools/perf/Documentation/perf-lock.txt b/tools/perf/Documentation/perf-lock.txt index 4958a1f..38e79d45 100644 --- a/tools/perf/Documentation/perf-lock.txt +++ b/tools/perf/Documentation/perf-lock.txt @@ -168,6 +168,10 @@ CONTENTION OPTIONS --entries=:: Display this many entries. +-l:: +--lock-addr:: + Show lock contention stat by address + SEE ALSO -------- diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c index 6fa3cdf..25c0a5e 100644 --- a/tools/perf/builtin-lock.c +++ b/tools/perf/builtin-lock.c @@ -56,6 +56,7 @@ static struct rb_root thread_stats; static bool combine_locks; static bool show_thread_stats; +static bool show_lock_addrs; static bool use_bpf; static unsigned long bpf_map_entries = 10240; static int max_stack_depth = CONTENTION_STACK_DEPTH; @@ -999,13 +1000,32 @@ static int report_lock_contention_begin_event(struct evsel *evsel, ls = lock_stat_find(key); if (!ls) { char buf[128]; - const char *caller = buf; + const char *name = ""; unsigned int flags = evsel__intval(evsel, sample, "flags"); + struct machine *machine = &session->machines.host; + struct map *kmap; + struct symbol *sym; + + switch (aggr_mode) { + case LOCK_AGGR_ADDR: + /* make sure it loads the kernel map to find lock symbols */ + map__load(machine__kernel_map(machine)); + + sym = machine__find_kernel_symbol(machine, key, &kmap); + if (sym) + name = sym->name; + break; + case LOCK_AGGR_CALLER: + name = buf; + if (lock_contention_caller(evsel, sample, buf, sizeof(buf)) < 0) + name = "Unknown"; + break; + case LOCK_AGGR_TASK: + default: + break; + } - if (lock_contention_caller(evsel, sample, buf, sizeof(buf)) < 0) - caller = "Unknown"; - - ls = lock_stat_findnew(key, caller, flags); + ls = lock_stat_findnew(key, name, flags); if (!ls) return -ENOMEM; @@ -1460,10 +1480,19 @@ static void print_contention_result(struct lock_contention *con) list_for_each_entry(key, &lock_keys, list) pr_info("%*s ", key->len, key->header); - if (show_thread_stats) + switch (aggr_mode) { + case LOCK_AGGR_TASK: pr_info(" %10s %s\n\n", "pid", "comm"); - else + break; + case LOCK_AGGR_CALLER: pr_info(" %10s %s\n\n", "type", "caller"); + break; + case LOCK_AGGR_ADDR: + pr_info(" %16s %s\n\n", "address", "symbol"); + break; + default: + break; + } } bad = total = printed = 0; @@ -1471,6 +1500,9 @@ static void print_contention_result(struct lock_contention *con) bad = bad_hist[BROKEN_CONTENDED]; while ((st = pop_from_result())) { + struct thread *t; + int pid; + total += use_bpf ? st->nr_contended : 1; if (st->broken) bad++; @@ -1480,18 +1512,24 @@ static void print_contention_result(struct lock_contention *con) pr_info(" "); } - if (show_thread_stats) { - struct thread *t; - int pid = st->addr; - - /* st->addr contains tid of thread */ + switch (aggr_mode) { + case LOCK_AGGR_CALLER: + pr_info(" %10s %s\n", get_type_str(st), st->name); + break; + case LOCK_AGGR_TASK: + pid = st->addr; t = perf_session__findnew(session, pid); pr_info(" %10d %s\n", pid, thread__comm_str(t)); - goto next; + break; + case LOCK_AGGR_ADDR: + pr_info(" %016llx %s\n", (unsigned long long)st->addr, + st->name ? : ""); + break; + default: + break; } - pr_info(" %10s %s\n", get_type_str(st), st->name); - if (verbose) { + if (aggr_mode == LOCK_AGGR_CALLER && verbose) { struct map *kmap; struct symbol *sym; char buf[128]; @@ -1508,7 +1546,6 @@ static void print_contention_result(struct lock_contention *con) } } -next: if (++printed >= print_nr_entries) break; } @@ -1616,7 +1653,6 @@ static int __cmd_contention(int argc, const char **argv) .map_nr_entries = bpf_map_entries, .max_stack = max_stack_depth, .stack_skip = stack_skip, - .aggr_mode = show_thread_stats ? LOCK_AGGR_TASK : LOCK_AGGR_CALLER, }; session = perf_session__new(use_bpf ? NULL : &data, &eops); @@ -1627,6 +1663,9 @@ static int __cmd_contention(int argc, const char **argv) con.machine = &session->machines.host; + con.aggr_mode = aggr_mode = show_thread_stats ? LOCK_AGGR_TASK : + show_lock_addrs ? LOCK_AGGR_ADDR : LOCK_AGGR_CALLER; + /* for lock function check */ symbol_conf.sort_by_name = true; symbol__init(&session->header.env); @@ -1907,6 +1946,7 @@ int cmd_lock(int argc, const char **argv) "Set the number of stack depth to skip when finding a lock caller, " "Default: " __stringify(CONTENTION_STACK_SKIP)), OPT_INTEGER('E', "entries", &print_nr_entries, "display this many functions"), + OPT_BOOLEAN('l', "lock-addr", &show_lock_addrs, "show lock stats by address"), OPT_PARENT(lock_options) }; @@ -1976,6 +2016,16 @@ int cmd_lock(int argc, const char **argv) argc = parse_options(argc, argv, contention_options, contention_usage, 0); } + + if (show_thread_stats && show_lock_addrs) { + pr_err("Cannot use thread and addr mode together\n"); + parse_options_usage(contention_usage, contention_options, + "threads", 0); + parse_options_usage(NULL, contention_options, + "lock-addr", 0); + return -1; + } + rc = __cmd_contention(argc, argv); } else { usage_with_options(lock_usage, lock_options); diff --git a/tools/perf/util/bpf_lock_contention.c b/tools/perf/util/bpf_lock_contention.c index 1590a9f..8e1b791 100644 --- a/tools/perf/util/bpf_lock_contention.c +++ b/tools/perf/util/bpf_lock_contention.c @@ -137,11 +137,15 @@ int lock_contention_read(struct lock_contention *con) thread__set_comm(idle, "swapper", /*timestamp=*/0); } + /* make sure it loads the kernel map */ + map__load(maps__first(machine->kmaps)); + 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 */ err = -1; @@ -160,24 +164,31 @@ int lock_contention_read(struct lock_contention *con) st->avg_wait_time = data.total_time / data.count; st->flags = data.flags; + st->addr = key.aggr_key; if (con->aggr_mode == LOCK_AGGR_TASK) { struct contention_task_data task; struct thread *t; - - st->addr = key.stack_or_task_id; + int pid = key.aggr_key; /* do not update idle comm which contains CPU number */ if (st->addr) { - bpf_map_lookup_elem(task_fd, &key, &task); - t = __machine__findnew_thread(machine, /*pid=*/-1, - key.stack_or_task_id); + 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; } - bpf_map_lookup_elem(stack, &key, stack_trace); + 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]) && diff --git a/tools/perf/util/bpf_skel/lock_contention.bpf.c b/tools/perf/util/bpf_skel/lock_contention.bpf.c index cd405ad..11b0fc7 100644 --- a/tools/perf/util/bpf_skel/lock_contention.bpf.c +++ b/tools/perf/util/bpf_skel/lock_contention.bpf.c @@ -168,11 +168,20 @@ int contention_end(u64 *ctx) duration = bpf_ktime_get_ns() - pelem->timestamp; - if (aggr_mode == LOCK_AGGR_CALLER) { - key.stack_or_task_id = pelem->stack_id; - } else { - key.stack_or_task_id = pid; + switch (aggr_mode) { + case LOCK_AGGR_CALLER: + key.aggr_key = pelem->stack_id; + break; + case LOCK_AGGR_TASK: + key.aggr_key = pid; update_task_data(pid); + break; + case LOCK_AGGR_ADDR: + key.aggr_key = pelem->lock; + break; + default: + /* should not happen */ + return 0; } data = bpf_map_lookup_elem(&lock_stat, &key); diff --git a/tools/perf/util/bpf_skel/lock_data.h b/tools/perf/util/bpf_skel/lock_data.h index dbdf4ca..ce71cf1 100644 --- a/tools/perf/util/bpf_skel/lock_data.h +++ b/tools/perf/util/bpf_skel/lock_data.h @@ -4,7 +4,7 @@ #define UTIL_BPF_SKEL_LOCK_DATA_H struct contention_key { - s32 stack_or_task_id; + u64 aggr_key; /* can be stack_id, pid or lock addr */ }; #define TASK_COMM_LEN 16 -- 2.7.4