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add futex
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@albertxu216
albertxu216 committed Sep 14, 2024
1 parent 66b4b53 commit 4804e40
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Showing 2 changed files with 146 additions and 14 deletions.
149 changes: 135 additions & 14 deletions eBPF_Supermarket/CPU_Subsystem/eBPF_proc_image/bpf/mfutex.bpf.c
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Original file line number Diff line number Diff line change
Expand Up @@ -73,13 +73,18 @@ struct {
__uint(max_entries,528 * 10240);
} mfutex_rb SEC(".maps");

// struct {
// __uint(type, BPF_MAP_TYPE_HASH);
// __uint(max_entries, 10240);
// __type(key, struct record_lock_key);
// __type(value, struct per_request);
// } futex_wait_queue SEC(".maps");//记录futex陷入内核

struct {
__uint(type, BPF_MAP_TYPE_HASH);
__uint(max_entries, 10240);
__type(key, struct lock_record_key);
__type(value, struct per_request);
} futex_wait_queue SEC(".maps");//记录futex陷入内核
struct {
__uint(type, BPF_MAP_TYPE_HASH);
__uint(max_entries, 10240);
__type(key, struct lock_record_key);
__type(value, struct per_request);
} futex_wake_queue SEC(".maps");//记录futex陷入内核

#define MUTEX_FLAG 1
#define RWLOCK_FLAG 2
Expand Down Expand Up @@ -280,15 +285,131 @@ int BPF_KPROBE(pthread_mutex_unlock_enter, void *__mutex)
// return 0;
// }

// SEC("tracepoint/syscall/sys_enter_futex")
// int trace_sys_enter_futex(struct sys_futex_args ctx){

// /*获取到要加入等待队列的线程，拿到时间*/
// SEC("kprobe/futex_wait")
// int BPF_KPROBE(trace_futex_wait,
// u32 __user *uaddr, unsigned int flags,
// u32 val, ktime_t *abs_time, u32 bitset)
// {
// }

/*1.将线程加入等待队列，并记录*/
SEC("kprobe/futex_wait")
int BPF_KPROBE(trace_futex_wait,
u32 *uaddr, unsigned int flags,
u32 val, ktime_t *abs_time, u32 bitset)
{
struct mfutex_ctrl *mfutex_ctrl = get_mfutex_ctrl();
if(!mfutex_ctrl)
return 0;
pid_t pid = bpf_get_current_pid_tgid();
int tgid = bpf_get_current_pid_tgid() >> 32;

if(mfutex_ctrl->target_pid == -1 && mfutex_ctrl->target_tgid == -1)//未指定目标进程或线程
return 0;
if((mfutex_ctrl->target_pid != -1 && pid!=mfutex_ctrl->target_pid)||
(mfutex_ctrl->target_tgid != -1 && tgid != mfutex_ctrl->target_tgid))//当前进程或线程非目标进程或线程
return 0;

u64 lock_ptr = (u64)uaddr;
int cpu = bpf_get_smp_processor_id();//获取当前cpu

// }
/*1.将 单个线程请求信息块 放入 请求等待队列futex_wait_queue*/
struct per_request per_request = {};
per_request.pid = pid;
per_request.start_request_time = bpf_ktime_get_ns();
per_request.cpu_id = cpu;
struct lock_record_key key = {};
key.lock_ptr = lock_ptr;
key.pid = pid;
bpf_map_update_elem(&futex_wait_queue, &key, &per_request, BPF_ANY);
// bpf_printk("Push_info:pid:%d ,lock_ptr:%lu, cnt:%d\n",per_request.pid,key.lock_ptr,key.cnt);
return 0;
}

/*2.将线程加入唤醒队列，从等待队列中删除
*2.1 将执行futex_wake的线程pid与锁地址进行匹配，便于在后面futex_wake_mark找到锁地址
*/
SEC("kprobe/futex_wake")
int BPF_KPROBE(trace_futex_wake,
u32 *uaddr, unsigned int flags,
int nr_wake, u32 bitset)
{
struct mfutex_ctrl *mfutex_ctrl = get_mfutex_ctrl();
if(!mfutex_ctrl)
return 0;
pid_t pid = bpf_get_current_pid_tgid();
int tgid = bpf_get_current_pid_tgid() >> 32;

if(mfutex_ctrl->target_pid == -1 && mfutex_ctrl->target_tgid == -1)//未指定目标进程或线程
return 0;
if((mfutex_ctrl->target_pid != -1 && pid!=mfutex_ctrl->target_pid)||
(mfutex_ctrl->target_tgid != -1 && tgid != mfutex_ctrl->target_tgid))//当前进程或线程非目标进程或线程
return 0;

u64 lock_ptr = (u64)uaddr;
struct proc_flag key={};
key.pid = pid;
key.flag = FUTEX_FLAG;
bpf_map_update_elem(&proc_unlock, &key, &lock_ptr, BPF_ANY);//将锁地址存在proc_unlock map中
return 0;
}
/*2.将线程加入唤醒队列，从等待队列中删除
*2.2 将要被唤醒的线程加入唤醒队列，并从等待队列中删除掉；
*/
SEC("kprobe/futex_wake_mark")
int BPF_KPROBE(trace_futex_wake_mark, struct wake_q_head *wake_q, struct futex_q *q)
{
struct mfutex_ctrl *mfutex_ctrl = get_mfutex_ctrl();
if(!mfutex_ctrl)
return 0;
pid_t pid = bpf_get_current_pid_tgid();
int tgid = bpf_get_current_pid_tgid() >> 32;

if(mfutex_ctrl->target_pid == -1 && mfutex_ctrl->target_tgid == -1)//未指定目标进程或线程
return 0;
if((mfutex_ctrl->target_pid != -1 && pid!=mfutex_ctrl->target_pid)||
(mfutex_ctrl->target_tgid != -1 && tgid != mfutex_ctrl->target_tgid))//当前进程或线程非目标进程或线程
return 0;

u64 *lock_ptr;
u64 temp_lock_ptr;
u64 ts = bpf_ktime_get_ns();

/*1.找到锁的地址*/
struct proc_flag proc_flag = {};
proc_flag.pid = pid;
proc_flag.flag = FUTEX_FLAG;
lock_ptr = bpf_map_lookup_elem(&proc_unlock, &proc_flag);
if(!lock_ptr) return 0;
temp_lock_ptr = *lock_ptr;

/*2.make key*/
struct lock_record_key key = {};
key.lock_ptr = temp_lock_ptr;
key.pid = BPF_CORE_READ(q,task,pid);

/*3.将线程从等待队列中删除*/
struct per_request *per_request;
per_request = bpf_map_lookup_elem(&futex_wait_queue, &key);
if(per_request) {//如果等待队列中找到该task 则尝试删除
bpf_map_delete_elem(&futex_wait_queue, &key);
per_request->start_hold_time = ts;
per_request->wait_delay = ts - per_request->start_hold_time;
}else{//如果没找到，说明该任务陷入阻塞时未记录，则创建per_request
struct per_request new_per_request = {};
new_per_request.pid = key.pid;
new_per_request.start_hold_time = ts;
per_request = &new_per_request;
}
/*4.将任务放到唤醒队列中*/
bpf_map_update_elem(&futex_wake_queue, &key, per_request, BPF_ANY);

/*5.传入rb*/
struct per_lock_event *e;
e = bpf_ringbuf_reserve(&mfutex_rb, sizeof(*e), 0);
if(!e)
return 0;
e->lock_ptr = temp_lock_ptr;
e->start_hold_time = ts;
e->type = FUTEX_FLAG;
bpf_ringbuf_submit(e, 0);
return 0;
}
11 changes: 11 additions & 0 deletions eBPF_Supermarket/CPU_Subsystem/eBPF_proc_image/include/proc_image.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -134,6 +134,7 @@ struct per_request{//每条锁请求信息
u64 start_request_time;
u64 start_hold_time;
u64 wait_delay;
int cpu_id;//在哪个cpu上阻塞了
};

struct lock_record_key{
Expand All @@ -152,6 +153,16 @@ struct per_lock_event{
u64 start_hold_time,last_hold_delay;//持有锁的时间；
int cnt;//等待锁+持有锁的数量；
};
struct sys_futex_args {
u64 pad;
int __syscall_nr;
u32 * uaddr;
int op;
u32 val;
const struct __kernel_timespec * utime;
u32 * uaddr2;
u32 val3;
};

// keytime_image
struct kt_ctrl{
Expand Down

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