// SPDX-License-Identifier: GPL-2.0
/*
* bpf_kwork_top.c
*
* Copyright (c) 2022 Huawei Inc, Yang Jihong <[email protected]>
*/
#include <time.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <unistd.h>
#include <linux/time64.h>
#include "util/debug.h"
#include "util/evsel.h"
#include "util/kwork.h"
#include <bpf/bpf.h>
#include <perf/cpumap.h>
#include "util/bpf_skel/kwork_top.skel.h"
/*
* This should be in sync with "util/kwork_top.bpf.c"
*/
#define MAX_COMMAND_LEN 16
struct time_data {
__u64 timestamp;
};
struct work_data {
__u64 runtime;
};
struct task_data {
__u32 tgid;
__u32 is_kthread;
char comm[MAX_COMMAND_LEN];
};
struct work_key {
__u32 type;
__u32 pid;
__u64 task_p;
};
struct task_key {
__u32 pid;
__u32 cpu;
};
struct kwork_class_bpf {
struct kwork_class *class;
void (*load_prepare)(void);
};
static struct kwork_top_bpf *skel;
void perf_kwork__top_start(void)
{
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
skel->bss->from_timestamp = (u64)ts.tv_sec * NSEC_PER_SEC + ts.tv_nsec;
skel->bss->enabled = 1;
pr_debug("perf kwork top start at: %lld\n", skel->bss->from_timestamp);
}
void perf_kwork__top_finish(void)
{
struct timespec ts;
skel->bss->enabled = 0;
clock_gettime(CLOCK_MONOTONIC, &ts);
skel->bss->to_timestamp = (u64)ts.tv_sec * NSEC_PER_SEC + ts.tv_nsec;
pr_debug("perf kwork top finish at: %lld\n", skel->bss->to_timestamp);
}
static void irq_load_prepare(void)
{
bpf_program__set_autoload(skel->progs.on_irq_handler_entry, true);
bpf_program__set_autoload(skel->progs.on_irq_handler_exit, true);
}
static struct kwork_class_bpf kwork_irq_bpf = {
.load_prepare = irq_load_prepare,
};
static void softirq_load_prepare(void)
{
bpf_program__set_autoload(skel->progs.on_softirq_entry, true);
bpf_program__set_autoload(skel->progs.on_softirq_exit, true);
}
static struct kwork_class_bpf kwork_softirq_bpf = {
.load_prepare = softirq_load_prepare,
};
static void sched_load_prepare(void)
{
bpf_program__set_autoload(skel->progs.on_switch, true);
}
static struct kwork_class_bpf kwork_sched_bpf = {
.load_prepare = sched_load_prepare,
};
static struct kwork_class_bpf *
kwork_class_bpf_supported_list[KWORK_CLASS_MAX] = {
[KWORK_CLASS_IRQ] = &kwork_irq_bpf,
[KWORK_CLASS_SOFTIRQ] = &kwork_softirq_bpf,
[KWORK_CLASS_SCHED] = &kwork_sched_bpf,
};
static bool valid_kwork_class_type(enum kwork_class_type type)
{
return type >= 0 && type < KWORK_CLASS_MAX;
}
static int setup_filters(struct perf_kwork *kwork)
{
if (kwork->cpu_list) {
int idx, nr_cpus, fd;
struct perf_cpu_map *map;
struct perf_cpu cpu;
fd = bpf_map__fd(skel->maps.kwork_top_cpu_filter);
if (fd < 0) {
pr_debug("Invalid cpu filter fd\n");
return -1;
}
map = perf_cpu_map__new(kwork->cpu_list);
if (!map) {
pr_debug("Invalid cpu_list\n");
return -1;
}
nr_cpus = libbpf_num_possible_cpus();
perf_cpu_map__for_each_cpu(cpu, idx, map) {
u8 val = 1;
if (cpu.cpu >= nr_cpus) {
perf_cpu_map__put(map);
pr_err("Requested cpu %d too large\n", cpu.cpu);
return -1;
}
bpf_map_update_elem(fd, &cpu.cpu, &val, BPF_ANY);
}
perf_cpu_map__put(map);
}
return 0;
}
int perf_kwork__top_prepare_bpf(struct perf_kwork *kwork)
{
struct bpf_program *prog;
struct kwork_class *class;
struct kwork_class_bpf *class_bpf;
enum kwork_class_type type;
skel = kwork_top_bpf__open();
if (!skel) {
pr_debug("Failed to open kwork top skeleton\n");
return -1;
}
/*
* set all progs to non-autoload,
* then set corresponding progs according to config
*/
bpf_object__for_each_program(prog, skel->obj)
bpf_program__set_autoload(prog, false);
list_for_each_entry(class, &kwork->class_list, list) {
type = class->type;
if (!valid_kwork_class_type(type) ||
!kwork_class_bpf_supported_list[type]) {
pr_err("Unsupported bpf trace class %s\n", class->name);
goto out;
}
class_bpf = kwork_class_bpf_supported_list[type];
class_bpf->class = class;
if (class_bpf->load_prepare)
class_bpf->load_prepare();
}
if (kwork->cpu_list)
skel->rodata->has_cpu_filter = 1;
if (kwork_top_bpf__load(skel)) {
pr_debug("Failed to load kwork top skeleton\n");
goto out;
}
if (setup_filters(kwork))
goto out;
if (kwork_top_bpf__attach(skel)) {
pr_debug("Failed to attach kwork top skeleton\n");
goto out;
}
return 0;
out:
kwork_top_bpf__destroy(skel);
return -1;
}
static void read_task_info(struct kwork_work *work)
{
int fd;
struct task_data data;
struct task_key key = {
.pid = work->id,
.cpu = work->cpu,
};
fd = bpf_map__fd(skel->maps.kwork_top_tasks);
if (fd < 0) {
pr_debug("Invalid top tasks map fd\n");
return;
}
if (!bpf_map_lookup_elem(fd, &key, &data)) {
work->tgid = data.tgid;
work->is_kthread = data.is_kthread;
work->name = strdup(data.comm);
}
}
static int add_work(struct perf_kwork *kwork, struct work_key *key,
struct work_data *data, int cpu)
{
struct kwork_class_bpf *bpf_trace;
struct kwork_work *work;
struct kwork_work tmp = {
.id = key->pid,
.cpu = cpu,
.name = NULL,
};
enum kwork_class_type type = key->type;
if (!valid_kwork_class_type(type)) {
pr_debug("Invalid class type %d to add work\n", type);
return -1;
}
bpf_trace = kwork_class_bpf_supported_list[type];
tmp.class = bpf_trace->class;
work = perf_kwork_add_work(kwork, tmp.class, &tmp);
if (!work)
return -1;
work->total_runtime = data->runtime;
read_task_info(work);
return 0;
}
int perf_kwork__top_read_bpf(struct perf_kwork *kwork)
{
int i, fd, nr_cpus;
struct work_data *data;
struct work_key key, prev;
fd = bpf_map__fd(skel->maps.kwork_top_works);
if (fd < 0) {
pr_debug("Invalid top runtime fd\n");
return -1;
}
nr_cpus = libbpf_num_possible_cpus();
data = calloc(nr_cpus, sizeof(struct work_data));
if (!data)
return -1;
memset(&prev, 0, sizeof(prev));
while (!bpf_map_get_next_key(fd, &prev, &key)) {
if ((bpf_map_lookup_elem(fd, &key, data)) != 0) {
pr_debug("Failed to lookup top elem\n");
return -1;
}
for (i = 0; i < nr_cpus; i++) {
if (data[i].runtime == 0)
continue;
if (add_work(kwork, &key, &data[i], i))
return -1;
}
prev = key;
}
free(data);
return 0;
}
void perf_kwork__top_cleanup_bpf(void)
{
kwork_top_bpf__destroy(skel);
}
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