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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /tools/perf/util/bpf_lock_contention.c
parentInitial commit. (diff)
downloadlinux-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_lock_contention.c')
-rw-r--r--tools/perf/util/bpf_lock_contention.c375
1 files changed, 375 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 000000000..e7dddf012
--- /dev/null
+++ b/tools/perf/util/bpf_lock_contention.c
@@ -0,0 +1,375 @@
+// 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.h"
+#include "util/thread_map.h"
+#include "util/lock-contention.h"
+#include <linux/zalloc.h>
+#include <linux/string.h>
+#include <bpf/bpf.h>
+
+#include "bpf_skel/lock_contention.skel.h"
+#include "bpf_skel/lock_data.h"
+
+static struct lock_contention_bpf *skel;
+
+int lock_contention_prepare(struct lock_contention *con)
+{
+ int i, fd;
+ int ncpus = 1, ntasks = 1, ntypes = 1, naddrs = 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_value_size(skel->maps.stacks, con->max_stack * sizeof(u64));
+ bpf_map__set_max_entries(skel->maps.lock_stat, con->map_nr_entries);
+ bpf_map__set_max_entries(skel->maps.tstamp, con->map_nr_entries);
+
+ if (con->aggr_mode == LOCK_AGGR_TASK)
+ bpf_map__set_max_entries(skel->maps.task_data, con->map_nr_entries);
+ else
+ bpf_map__set_max_entries(skel->maps.task_data, 1);
+
+ if (con->save_callstack)
+ bpf_map__set_max_entries(skel->maps.stacks, con->map_nr_entries);
+ else
+ bpf_map__set_max_entries(skel->maps.stacks, 1);
+
+ 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);
+ if (con->filters->nr_types)
+ ntypes = con->filters->nr_types;
+
+ /* resolve lock name filters to addr */
+ if (con->filters->nr_syms) {
+ struct symbol *sym;
+ struct map *kmap;
+ unsigned long *addrs;
+
+ for (i = 0; i < con->filters->nr_syms; i++) {
+ sym = machine__find_kernel_symbol_by_name(con->machine,
+ con->filters->syms[i],
+ &kmap);
+ if (sym == NULL) {
+ pr_warning("ignore unknown symbol: %s\n",
+ con->filters->syms[i]);
+ continue;
+ }
+
+ addrs = realloc(con->filters->addrs,
+ (con->filters->nr_addrs + 1) * sizeof(*addrs));
+ if (addrs == NULL) {
+ pr_warning("memory allocation failure\n");
+ continue;
+ }
+
+ addrs[con->filters->nr_addrs++] = map__unmap_ip(kmap, sym->start);
+ con->filters->addrs = addrs;
+ }
+ naddrs = con->filters->nr_addrs;
+ }
+
+ bpf_map__set_max_entries(skel->maps.cpu_filter, ncpus);
+ bpf_map__set_max_entries(skel->maps.task_filter, ntasks);
+ bpf_map__set_max_entries(skel->maps.type_filter, ntypes);
+ bpf_map__set_max_entries(skel->maps.addr_filter, naddrs);
+
+ 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);
+ }
+
+ if (con->filters->nr_types) {
+ u8 val = 1;
+
+ skel->bss->has_type = 1;
+ fd = bpf_map__fd(skel->maps.type_filter);
+
+ for (i = 0; i < con->filters->nr_types; i++)
+ bpf_map_update_elem(fd, &con->filters->types[i], &val, BPF_ANY);
+ }
+
+ if (con->filters->nr_addrs) {
+ u8 val = 1;
+
+ skel->bss->has_addr = 1;
+ fd = bpf_map__fd(skel->maps.addr_filter);
+
+ for (i = 0; i < con->filters->nr_addrs; i++)
+ bpf_map_update_elem(fd, &con->filters->addrs[i], &val, BPF_ANY);
+ }
+
+ /* these don't work well if in the rodata section */
+ skel->bss->stack_skip = con->stack_skip;
+ skel->bss->aggr_mode = con->aggr_mode;
+ skel->bss->needs_callstack = con->save_callstack;
+ skel->bss->lock_owner = con->owner;
+
+ bpf_program__set_autoload(skel->progs.collect_lock_syms, false);
+
+ 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;
+}
+
+static const char *lock_contention_get_name(struct lock_contention *con,
+ struct contention_key *key,
+ u64 *stack_trace, u32 flags)
+{
+ 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->pid;
+ 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) {
+ int lock_fd = bpf_map__fd(skel->maps.lock_syms);
+
+ /* per-process locks set upper bits of the flags */
+ if (flags & LCD_F_MMAP_LOCK)
+ return "mmap_lock";
+ if (flags & LCD_F_SIGHAND_LOCK)
+ return "siglock";
+
+ /* global locks with symbols */
+ sym = machine__find_kernel_symbol(machine, key->lock_addr, &kmap);
+ if (sym)
+ return sym->name;
+
+ /* try semi-global locks collected separately */
+ if (!bpf_map_lookup_elem(lock_fd, &key->lock_addr, &flags)) {
+ if (flags == LOCK_CLASS_RQLOCK)
+ return "rq_lock";
+ }
+
+ return "";
+ }
+
+ /* 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 = map__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, err = 0;
+ struct contention_key *prev_key, key = {};
+ struct contention_data data = {};
+ struct lock_stat *st = NULL;
+ struct machine *machine = con->machine;
+ u64 *stack_trace;
+ size_t stack_size = con->max_stack * sizeof(*stack_trace);
+
+ fd = bpf_map__fd(skel->maps.lock_stat);
+ stack = bpf_map__fd(skel->maps.stacks);
+
+ con->fails.task = skel->bss->task_fail;
+ con->fails.stack = skel->bss->stack_fail;
+ con->fails.time = skel->bss->time_fail;
+ con->fails.data = skel->bss->data_fail;
+
+ stack_trace = zalloc(stack_size);
+ if (stack_trace == NULL)
+ return -1;
+
+ if (con->aggr_mode == LOCK_AGGR_TASK) {
+ struct thread *idle = __machine__findnew_thread(machine,
+ /*pid=*/0,
+ /*tid=*/0);
+ thread__set_comm(idle, "swapper", /*timestamp=*/0);
+ }
+
+ if (con->aggr_mode == LOCK_AGGR_ADDR) {
+ DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts,
+ .flags = BPF_F_TEST_RUN_ON_CPU,
+ );
+ int prog_fd = bpf_program__fd(skel->progs.collect_lock_syms);
+
+ bpf_prog_test_run_opts(prog_fd, &opts);
+ }
+
+ /* make sure it loads the kernel map */
+ map__load(maps__first(machine->kmaps)->map);
+
+ prev_key = NULL;
+ while (!bpf_map_get_next_key(fd, prev_key, &key)) {
+ s64 ls_key;
+ const char *name;
+
+ /* to handle errors in the loop body */
+ err = -1;
+
+ bpf_map_lookup_elem(fd, &key, &data);
+ if (con->save_callstack) {
+ bpf_map_lookup_elem(stack, &key.stack_id, stack_trace);
+
+ if (!match_callstack_filter(machine, stack_trace)) {
+ con->nr_filtered += data.count;
+ goto next;
+ }
+ }
+
+ switch (con->aggr_mode) {
+ case LOCK_AGGR_CALLER:
+ ls_key = key.stack_id;
+ break;
+ case LOCK_AGGR_TASK:
+ ls_key = key.pid;
+ break;
+ case LOCK_AGGR_ADDR:
+ ls_key = key.lock_addr;
+ break;
+ default:
+ goto next;
+ }
+
+ st = lock_stat_find(ls_key);
+ if (st != NULL) {
+ st->wait_time_total += data.total_time;
+ if (st->wait_time_max < data.max_time)
+ st->wait_time_max = data.max_time;
+ if (st->wait_time_min > data.min_time)
+ st->wait_time_min = data.min_time;
+
+ st->nr_contended += data.count;
+ if (st->nr_contended)
+ st->avg_wait_time = st->wait_time_total / st->nr_contended;
+ goto next;
+ }
+
+ name = lock_contention_get_name(con, &key, stack_trace, data.flags);
+ st = lock_stat_findnew(ls_key, name, data.flags);
+ if (st == NULL)
+ break;
+
+ 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;
+
+ if (con->aggr_mode == LOCK_AGGR_CALLER && verbose > 0) {
+ st->callstack = memdup(stack_trace, stack_size);
+ if (st->callstack == NULL)
+ break;
+ }
+
+next:
+ prev_key = &key;
+
+ /* we're fine now, reset the error */
+ err = 0;
+ }
+
+ free(stack_trace);
+
+ return err;
+}
+
+int lock_contention_finish(void)
+{
+ if (skel) {
+ skel->bss->enabled = 0;
+ lock_contention_bpf__destroy(skel);
+ }
+
+ return 0;
+}