// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
// Copyright (c) 2022, Huawei
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_core_read.h>
/*
* This should be in sync with "util/kwork.h"
*/
enum kwork_class_type {
KWORK_CLASS_IRQ,
KWORK_CLASS_SOFTIRQ,
KWORK_CLASS_WORKQUEUE,
KWORK_CLASS_SCHED,
KWORK_CLASS_MAX,
};
#define MAX_ENTRIES 102400
#define MAX_NR_CPUS 2048
#define PF_KTHREAD 0x00200000
#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 {
__uint(type, BPF_MAP_TYPE_TASK_STORAGE);
__uint(map_flags, BPF_F_NO_PREALLOC);
__type(key, int);
__type(value, struct time_data);
} kwork_top_task_time SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_PERCPU_HASH);
__uint(key_size, sizeof(struct work_key));
__uint(value_size, sizeof(struct time_data));
__uint(max_entries, MAX_ENTRIES);
} kwork_top_irq_time SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_HASH);
__uint(key_size, sizeof(struct task_key));
__uint(value_size, sizeof(struct task_data));
__uint(max_entries, MAX_ENTRIES);
} kwork_top_tasks SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_PERCPU_HASH);
__uint(key_size, sizeof(struct work_key));
__uint(value_size, sizeof(struct work_data));
__uint(max_entries, MAX_ENTRIES);
} kwork_top_works SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_HASH);
__uint(key_size, sizeof(u32));
__uint(value_size, sizeof(u8));
__uint(max_entries, MAX_NR_CPUS);
} kwork_top_cpu_filter SEC(".maps");
int enabled = 0;
int has_cpu_filter = 0;
__u64 from_timestamp = 0;
__u64 to_timestamp = 0;
static __always_inline int cpu_is_filtered(__u32 cpu)
{
__u8 *cpu_val;
if (has_cpu_filter) {
cpu_val = bpf_map_lookup_elem(&kwork_top_cpu_filter, &cpu);
if (!cpu_val)
return 1;
}
return 0;
}
static __always_inline void update_task_info(struct task_struct *task, __u32 cpu)
{
struct task_key key = {
.pid = task->pid,
.cpu = cpu,
};
if (!bpf_map_lookup_elem(&kwork_top_tasks, &key)) {
struct task_data data = {
.tgid = task->tgid,
.is_kthread = task->flags & PF_KTHREAD ? 1 : 0,
};
BPF_CORE_READ_STR_INTO(&data.comm, task, comm);
bpf_map_update_elem(&kwork_top_tasks, &key, &data, BPF_ANY);
}
}
static __always_inline void update_work(struct work_key *key, __u64 delta)
{
struct work_data *data;
data = bpf_map_lookup_elem(&kwork_top_works, key);
if (data) {
data->runtime += delta;
} else {
struct work_data new_data = {
.runtime = delta,
};
bpf_map_update_elem(&kwork_top_works, key, &new_data, BPF_ANY);
}
}
static void on_sched_out(struct task_struct *task, __u64 ts, __u32 cpu)
{
__u64 delta;
struct time_data *pelem;
pelem = bpf_task_storage_get(&kwork_top_task_time, task, NULL, 0);
if (pelem)
delta = ts - pelem->timestamp;
else
delta = ts - from_timestamp;
struct work_key key = {
.type = KWORK_CLASS_SCHED,
.pid = task->pid,
.task_p = (__u64)task,
};
update_work(&key, delta);
update_task_info(task, cpu);
}
static void on_sched_in(struct task_struct *task, __u64 ts)
{
struct time_data *pelem;
pelem = bpf_task_storage_get(&kwork_top_task_time, task, NULL,
BPF_LOCAL_STORAGE_GET_F_CREATE);
if (pelem)
pelem->timestamp = ts;
}
SEC("tp_btf/sched_switch")
int on_switch(u64 *ctx)
{
struct task_struct *prev, *next;
prev = (struct task_struct *)ctx[1];
next = (struct task_struct *)ctx[2];
if (!enabled)
return 0;
__u32 cpu = bpf_get_smp_processor_id();
if (cpu_is_filtered(cpu))
return 0;
__u64 ts = bpf_ktime_get_ns();
on_sched_out(prev, ts, cpu);
on_sched_in(next, ts);
return 0;
}
SEC("tp_btf/irq_handler_entry")
int on_irq_handler_entry(u64 *cxt)
{
struct task_struct *task;
if (!enabled)
return 0;
__u32 cpu = bpf_get_smp_processor_id();
if (cpu_is_filtered(cpu))
return 0;
__u64 ts = bpf_ktime_get_ns();
task = (struct task_struct *)bpf_get_current_task();
if (!task)
return 0;
struct work_key key = {
.type = KWORK_CLASS_IRQ,
.pid = BPF_CORE_READ(task, pid),
.task_p = (__u64)task,
};
struct time_data data = {
.timestamp = ts,
};
bpf_map_update_elem(&kwork_top_irq_time, &key, &data, BPF_ANY);
return 0;
}
SEC("tp_btf/irq_handler_exit")
int on_irq_handler_exit(u64 *cxt)
{
__u64 delta;
struct task_struct *task;
struct time_data *pelem;
if (!enabled)
return 0;
__u32 cpu = bpf_get_smp_processor_id();
if (cpu_is_filtered(cpu))
return 0;
__u64 ts = bpf_ktime_get_ns();
task = (struct task_struct *)bpf_get_current_task();
if (!task)
return 0;
struct work_key key = {
.type = KWORK_CLASS_IRQ,
.pid = BPF_CORE_READ(task, pid),
.task_p = (__u64)task,
};
pelem = bpf_map_lookup_elem(&kwork_top_irq_time, &key);
if (pelem && pelem->timestamp != 0)
delta = ts - pelem->timestamp;
else
delta = ts - from_timestamp;
update_work(&key, delta);
return 0;
}
SEC("tp_btf/softirq_entry")
int on_softirq_entry(u64 *cxt)
{
struct task_struct *task;
if (!enabled)
return 0;
__u32 cpu = bpf_get_smp_processor_id();
if (cpu_is_filtered(cpu))
return 0;
__u64 ts = bpf_ktime_get_ns();
task = (struct task_struct *)bpf_get_current_task();
if (!task)
return 0;
struct work_key key = {
.type = KWORK_CLASS_SOFTIRQ,
.pid = BPF_CORE_READ(task, pid),
.task_p = (__u64)task,
};
struct time_data data = {
.timestamp = ts,
};
bpf_map_update_elem(&kwork_top_irq_time, &key, &data, BPF_ANY);
return 0;
}
SEC("tp_btf/softirq_exit")
int on_softirq_exit(u64 *cxt)
{
__u64 delta;
struct task_struct *task;
struct time_data *pelem;
if (!enabled)
return 0;
__u32 cpu = bpf_get_smp_processor_id();
if (cpu_is_filtered(cpu))
return 0;
__u64 ts = bpf_ktime_get_ns();
task = (struct task_struct *)bpf_get_current_task();
if (!task)
return 0;
struct work_key key = {
.type = KWORK_CLASS_SOFTIRQ,
.pid = BPF_CORE_READ(task, pid),
.task_p = (__u64)task,
};
pelem = bpf_map_lookup_elem(&kwork_top_irq_time, &key);
if (pelem)
delta = ts - pelem->timestamp;
else
delta = ts - from_timestamp;
update_work(&key, delta);
return 0;
}
char LICENSE[] SEC("license") = "Dual BSD/GPL";
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