// SPDX-License-Identifier: GPL-2.0
/*
* bpf_kwork.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_trace.skel.h"
/*
* This should be in sync with "util/kwork_trace.bpf.c"
*/
#define MAX_KWORKNAME 128
struct work_key {
u32 type;
u32 cpu;
u64 id;
};
struct report_data {
u64 nr;
u64 total_time;
u64 max_time;
u64 max_time_start;
u64 max_time_end;
};
struct kwork_class_bpf {
struct kwork_class *class;
void (*load_prepare)(struct perf_kwork *kwork);
int (*get_work_name)(struct work_key *key, char **ret_name);
};
static struct kwork_trace_bpf *skel;
static struct timespec ts_start;
static struct timespec ts_end;
void perf_kwork__trace_start(void)
{
clock_gettime(CLOCK_MONOTONIC, &ts_start);
skel->bss->enabled = 1;
}
void perf_kwork__trace_finish(void)
{
clock_gettime(CLOCK_MONOTONIC, &ts_end);
skel->bss->enabled = 0;
}
static int get_work_name_from_map(struct work_key *key, char **ret_name)
{
char name[MAX_KWORKNAME] = { 0 };
int fd = bpf_map__fd(skel->maps.perf_kwork_names);
*ret_name = NULL;
if (fd < 0) {
pr_debug("Invalid names map fd\n");
return 0;
}
if ((bpf_map_lookup_elem(fd, key, name) == 0) && (strlen(name) != 0)) {
*ret_name = strdup(name);
if (*ret_name == NULL) {
pr_err("Failed to copy work name\n");
return -1;
}
}
return 0;
}
static void irq_load_prepare(struct perf_kwork *kwork)
{
if (kwork->report == KWORK_REPORT_RUNTIME) {
bpf_program__set_autoload(skel->progs.report_irq_handler_entry, true);
bpf_program__set_autoload(skel->progs.report_irq_handler_exit, true);
}
}
static struct kwork_class_bpf kwork_irq_bpf = {
.load_prepare = irq_load_prepare,
.get_work_name = get_work_name_from_map,
};
static void softirq_load_prepare(struct perf_kwork *kwork)
{
if (kwork->report == KWORK_REPORT_RUNTIME) {
bpf_program__set_autoload(skel->progs.report_softirq_entry, true);
bpf_program__set_autoload(skel->progs.report_softirq_exit, true);
} else if (kwork->report == KWORK_REPORT_LATENCY) {
bpf_program__set_autoload(skel->progs.latency_softirq_raise, true);
bpf_program__set_autoload(skel->progs.latency_softirq_entry, true);
}
}
static struct kwork_class_bpf kwork_softirq_bpf = {
.load_prepare = softirq_load_prepare,
.get_work_name = get_work_name_from_map,
};
static void workqueue_load_prepare(struct perf_kwork *kwork)
{
if (kwork->report == KWORK_REPORT_RUNTIME) {
bpf_program__set_autoload(skel->progs.report_workqueue_execute_start, true);
bpf_program__set_autoload(skel->progs.report_workqueue_execute_end, true);
} else if (kwork->report == KWORK_REPORT_LATENCY) {
bpf_program__set_autoload(skel->progs.latency_workqueue_activate_work, true);
bpf_program__set_autoload(skel->progs.latency_workqueue_execute_start, true);
}
}
static struct kwork_class_bpf kwork_workqueue_bpf = {
.load_prepare = workqueue_load_prepare,
.get_work_name = get_work_name_from_map,
};
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_WORKQUEUE] = &kwork_workqueue_bpf,
};
static bool valid_kwork_class_type(enum kwork_class_type type)
{
return type >= 0 && type < KWORK_CLASS_MAX ? true : false;
}
static int setup_filters(struct perf_kwork *kwork)
{
if (kwork->cpu_list != NULL) {
int idx, nr_cpus;
struct perf_cpu_map *map;
struct perf_cpu cpu;
int fd = bpf_map__fd(skel->maps.perf_kwork_cpu_filter);
if (fd < 0) {
pr_debug("Invalid cpu filter fd\n");
return -1;
}
map = perf_cpu_map__new(kwork->cpu_list);
if (map == NULL) {
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);
}
if (kwork->profile_name != NULL) {
int key, fd;
if (strlen(kwork->profile_name) >= MAX_KWORKNAME) {
pr_err("Requested name filter %s too large, limit to %d\n",
kwork->profile_name, MAX_KWORKNAME - 1);
return -1;
}
fd = bpf_map__fd(skel->maps.perf_kwork_name_filter);
if (fd < 0) {
pr_debug("Invalid name filter fd\n");
return -1;
}
key = 0;
bpf_map_update_elem(fd, &key, kwork->profile_name, BPF_ANY);
}
return 0;
}
int perf_kwork__trace_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_trace_bpf__open();
if (!skel) {
pr_debug("Failed to open kwork trace 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] == NULL)) {
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 != NULL)
class_bpf->load_prepare(kwork);
}
if (kwork->cpu_list != NULL)
skel->rodata->has_cpu_filter = 1;
if (kwork->profile_name != NULL)
skel->rodata->has_name_filter = 1;
if (kwork_trace_bpf__load(skel)) {
pr_debug("Failed to load kwork trace skeleton\n");
goto out;
}
if (setup_filters(kwork))
goto out;
if (kwork_trace_bpf__attach(skel)) {
pr_debug("Failed to attach kwork trace skeleton\n");
goto out;
}
return 0;
out:
kwork_trace_bpf__destroy(skel);
return -1;
}
static int add_work(struct perf_kwork *kwork,
struct work_key *key,
struct report_data *data)
{
struct kwork_work *work;
struct kwork_class_bpf *bpf_trace;
struct kwork_work tmp = {
.id = key->id,
.name = NULL,
.cpu = key->cpu,
};
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;
if ((bpf_trace->get_work_name != NULL) &&
(bpf_trace->get_work_name(key, &tmp.name)))
return -1;
work = perf_kwork_add_work(kwork, tmp.class, &tmp);
if (work == NULL)
return -1;
if (kwork->report == KWORK_REPORT_RUNTIME) {
work->nr_atoms = data->nr;
work->total_runtime = data->total_time;
work->max_runtime = data->max_time;
work->max_runtime_start = data->max_time_start;
work->max_runtime_end = data->max_time_end;
} else if (kwork->report == KWORK_REPORT_LATENCY) {
work->nr_atoms = data->nr;
work->total_latency = data->total_time;
work->max_latency = data->max_time;
work->max_latency_start = data->max_time_start;
work->max_latency_end = data->max_time_end;
} else {
pr_debug("Invalid bpf report type %d\n", kwork->report);
return -1;
}
kwork->timestart = (u64)ts_start.tv_sec * NSEC_PER_SEC + ts_start.tv_nsec;
kwork->timeend = (u64)ts_end.tv_sec * NSEC_PER_SEC + ts_end.tv_nsec;
return 0;
}
int perf_kwork__report_read_bpf(struct perf_kwork *kwork)
{
struct report_data data;
struct work_key key = {
.type = 0,
.cpu = 0,
.id = 0,
};
struct work_key prev = {
.type = 0,
.cpu = 0,
.id = 0,
};
int fd = bpf_map__fd(skel->maps.perf_kwork_report);
if (fd < 0) {
pr_debug("Invalid report fd\n");
return -1;
}
while (!bpf_map_get_next_key(fd, &prev, &key)) {
if ((bpf_map_lookup_elem(fd, &key, &data)) != 0) {
pr_debug("Failed to lookup report elem\n");
return -1;
}
if ((data.nr != 0) && (add_work(kwork, &key, &data) != 0))
return -1;
prev = key;
}
return 0;
}
void perf_kwork__report_cleanup_bpf(void)
{
kwork_trace_bpf__destroy(skel);
}
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