344 lines
8.2 KiB
C
344 lines
8.2 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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#include "util/debug.h"
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#include "util/evlist.h"
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#include "util/machine.h"
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#include "util/map.h"
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#include "util/symbol.h"
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#include "util/target.h"
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#include "util/thread.h"
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#include "util/thread_map.h"
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#include "util/lock-contention.h"
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#include <linux/zalloc.h>
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#include <linux/string.h>
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#include <bpf/bpf.h>
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#include "bpf_skel/lock_contention.skel.h"
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#include "bpf_skel/lock_data.h"
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static struct lock_contention_bpf *skel;
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int lock_contention_prepare(struct lock_contention *con)
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{
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int i, fd;
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int ncpus = 1, ntasks = 1, ntypes = 1, naddrs = 1;
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struct evlist *evlist = con->evlist;
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struct target *target = con->target;
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skel = lock_contention_bpf__open();
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if (!skel) {
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pr_err("Failed to open lock-contention BPF skeleton\n");
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return -1;
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}
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bpf_map__set_value_size(skel->maps.stacks, con->max_stack * sizeof(u64));
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bpf_map__set_max_entries(skel->maps.lock_stat, con->map_nr_entries);
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bpf_map__set_max_entries(skel->maps.tstamp, con->map_nr_entries);
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if (con->aggr_mode == LOCK_AGGR_TASK)
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bpf_map__set_max_entries(skel->maps.task_data, con->map_nr_entries);
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else
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bpf_map__set_max_entries(skel->maps.task_data, 1);
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if (con->save_callstack)
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bpf_map__set_max_entries(skel->maps.stacks, con->map_nr_entries);
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else
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bpf_map__set_max_entries(skel->maps.stacks, 1);
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if (target__has_cpu(target))
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ncpus = perf_cpu_map__nr(evlist->core.user_requested_cpus);
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if (target__has_task(target))
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ntasks = perf_thread_map__nr(evlist->core.threads);
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if (con->filters->nr_types)
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ntypes = con->filters->nr_types;
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/* resolve lock name filters to addr */
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if (con->filters->nr_syms) {
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struct symbol *sym;
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struct map *kmap;
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unsigned long *addrs;
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for (i = 0; i < con->filters->nr_syms; i++) {
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sym = machine__find_kernel_symbol_by_name(con->machine,
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con->filters->syms[i],
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&kmap);
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if (sym == NULL) {
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pr_warning("ignore unknown symbol: %s\n",
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con->filters->syms[i]);
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continue;
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}
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addrs = realloc(con->filters->addrs,
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(con->filters->nr_addrs + 1) * sizeof(*addrs));
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if (addrs == NULL) {
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pr_warning("memory allocation failure\n");
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continue;
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}
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addrs[con->filters->nr_addrs++] = kmap->unmap_ip(kmap, sym->start);
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con->filters->addrs = addrs;
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}
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naddrs = con->filters->nr_addrs;
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}
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bpf_map__set_max_entries(skel->maps.cpu_filter, ncpus);
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bpf_map__set_max_entries(skel->maps.task_filter, ntasks);
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bpf_map__set_max_entries(skel->maps.type_filter, ntypes);
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bpf_map__set_max_entries(skel->maps.addr_filter, naddrs);
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if (lock_contention_bpf__load(skel) < 0) {
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pr_err("Failed to load lock-contention BPF skeleton\n");
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return -1;
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}
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if (target__has_cpu(target)) {
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u32 cpu;
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u8 val = 1;
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skel->bss->has_cpu = 1;
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fd = bpf_map__fd(skel->maps.cpu_filter);
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for (i = 0; i < ncpus; i++) {
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cpu = perf_cpu_map__cpu(evlist->core.user_requested_cpus, i).cpu;
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bpf_map_update_elem(fd, &cpu, &val, BPF_ANY);
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}
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}
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if (target__has_task(target)) {
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u32 pid;
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u8 val = 1;
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skel->bss->has_task = 1;
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fd = bpf_map__fd(skel->maps.task_filter);
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for (i = 0; i < ntasks; i++) {
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pid = perf_thread_map__pid(evlist->core.threads, i);
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bpf_map_update_elem(fd, &pid, &val, BPF_ANY);
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}
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}
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if (target__none(target) && evlist->workload.pid > 0) {
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u32 pid = evlist->workload.pid;
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u8 val = 1;
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skel->bss->has_task = 1;
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fd = bpf_map__fd(skel->maps.task_filter);
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bpf_map_update_elem(fd, &pid, &val, BPF_ANY);
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}
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if (con->filters->nr_types) {
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u8 val = 1;
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skel->bss->has_type = 1;
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fd = bpf_map__fd(skel->maps.type_filter);
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for (i = 0; i < con->filters->nr_types; i++)
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bpf_map_update_elem(fd, &con->filters->types[i], &val, BPF_ANY);
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}
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if (con->filters->nr_addrs) {
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u8 val = 1;
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skel->bss->has_addr = 1;
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fd = bpf_map__fd(skel->maps.addr_filter);
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for (i = 0; i < con->filters->nr_addrs; i++)
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bpf_map_update_elem(fd, &con->filters->addrs[i], &val, BPF_ANY);
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}
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/* these don't work well if in the rodata section */
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skel->bss->stack_skip = con->stack_skip;
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skel->bss->aggr_mode = con->aggr_mode;
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skel->bss->needs_callstack = con->save_callstack;
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skel->bss->lock_owner = con->owner;
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lock_contention_bpf__attach(skel);
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return 0;
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}
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int lock_contention_start(void)
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{
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skel->bss->enabled = 1;
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return 0;
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}
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int lock_contention_stop(void)
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{
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skel->bss->enabled = 0;
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return 0;
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}
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static const char *lock_contention_get_name(struct lock_contention *con,
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struct contention_key *key,
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u64 *stack_trace)
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{
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int idx = 0;
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u64 addr;
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const char *name = "";
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static char name_buf[KSYM_NAME_LEN];
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struct symbol *sym;
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struct map *kmap;
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struct machine *machine = con->machine;
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if (con->aggr_mode == LOCK_AGGR_TASK) {
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struct contention_task_data task;
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int pid = key->pid;
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int task_fd = bpf_map__fd(skel->maps.task_data);
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/* do not update idle comm which contains CPU number */
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if (pid) {
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struct thread *t = __machine__findnew_thread(machine, /*pid=*/-1, pid);
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if (t == NULL)
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return name;
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if (!bpf_map_lookup_elem(task_fd, &pid, &task) &&
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thread__set_comm(t, task.comm, /*timestamp=*/0))
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name = task.comm;
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}
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return name;
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}
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if (con->aggr_mode == LOCK_AGGR_ADDR) {
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sym = machine__find_kernel_symbol(machine, key->lock_addr, &kmap);
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if (sym)
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name = sym->name;
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return name;
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}
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/* LOCK_AGGR_CALLER: skip lock internal functions */
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while (machine__is_lock_function(machine, stack_trace[idx]) &&
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idx < con->max_stack - 1)
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idx++;
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addr = stack_trace[idx];
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sym = machine__find_kernel_symbol(machine, addr, &kmap);
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if (sym) {
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unsigned long offset;
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offset = kmap->map_ip(kmap, addr) - sym->start;
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if (offset == 0)
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return sym->name;
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snprintf(name_buf, sizeof(name_buf), "%s+%#lx", sym->name, offset);
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} else {
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snprintf(name_buf, sizeof(name_buf), "%#lx", (unsigned long)addr);
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}
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return name_buf;
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}
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int lock_contention_read(struct lock_contention *con)
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{
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int fd, stack, err = 0;
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struct contention_key *prev_key, key;
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struct contention_data data = {};
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struct lock_stat *st = NULL;
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struct machine *machine = con->machine;
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u64 *stack_trace;
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size_t stack_size = con->max_stack * sizeof(*stack_trace);
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fd = bpf_map__fd(skel->maps.lock_stat);
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stack = bpf_map__fd(skel->maps.stacks);
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con->lost = skel->bss->lost;
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stack_trace = zalloc(stack_size);
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if (stack_trace == NULL)
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return -1;
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if (con->aggr_mode == LOCK_AGGR_TASK) {
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struct thread *idle = __machine__findnew_thread(machine,
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/*pid=*/0,
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/*tid=*/0);
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thread__set_comm(idle, "swapper", /*timestamp=*/0);
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}
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/* make sure it loads the kernel map */
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map__load(maps__first(machine->kmaps));
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prev_key = NULL;
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while (!bpf_map_get_next_key(fd, prev_key, &key)) {
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s64 ls_key;
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const char *name;
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/* to handle errors in the loop body */
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err = -1;
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bpf_map_lookup_elem(fd, &key, &data);
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if (con->save_callstack) {
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bpf_map_lookup_elem(stack, &key.stack_id, stack_trace);
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if (!match_callstack_filter(machine, stack_trace))
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goto next;
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}
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switch (con->aggr_mode) {
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case LOCK_AGGR_CALLER:
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ls_key = key.stack_id;
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break;
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case LOCK_AGGR_TASK:
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ls_key = key.pid;
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break;
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case LOCK_AGGR_ADDR:
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ls_key = key.lock_addr;
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break;
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default:
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goto next;
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}
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st = lock_stat_find(ls_key);
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if (st != NULL) {
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st->wait_time_total += data.total_time;
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if (st->wait_time_max < data.max_time)
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st->wait_time_max = data.max_time;
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if (st->wait_time_min > data.min_time)
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st->wait_time_min = data.min_time;
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st->nr_contended += data.count;
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if (st->nr_contended)
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st->avg_wait_time = st->wait_time_total / st->nr_contended;
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goto next;
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}
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name = lock_contention_get_name(con, &key, stack_trace);
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st = lock_stat_findnew(ls_key, name, data.flags);
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if (st == NULL)
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break;
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st->nr_contended = data.count;
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st->wait_time_total = data.total_time;
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st->wait_time_max = data.max_time;
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st->wait_time_min = data.min_time;
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if (data.count)
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st->avg_wait_time = data.total_time / data.count;
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if (con->save_callstack) {
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st->callstack = memdup(stack_trace, stack_size);
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if (st->callstack == NULL)
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break;
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}
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next:
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prev_key = &key;
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/* we're fine now, reset the error */
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err = 0;
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}
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free(stack_trace);
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return err;
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}
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int lock_contention_finish(void)
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{
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if (skel) {
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skel->bss->enabled = 0;
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lock_contention_bpf__destroy(skel);
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}
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return 0;
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}
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