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157 lines
3.8 KiB
157 lines
3.8 KiB
/* Copyright (c) 2016 Facebook |
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* |
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* This program is free software; you can redistribute it and/or |
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* modify it under the terms of version 2 of the GNU General Public |
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* License as published by the Free Software Foundation. |
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*/ |
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#include <uapi/linux/bpf.h> |
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#include <uapi/linux/ptrace.h> |
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#include <uapi/linux/perf_event.h> |
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#include <linux/version.h> |
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#include <linux/sched.h> |
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#include <bpf/bpf_helpers.h> |
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#include <bpf/bpf_tracing.h> |
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#define _(P) \ |
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({ \ |
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typeof(P) val; \ |
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bpf_probe_read_kernel(&val, sizeof(val), &(P)); \ |
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val; \ |
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}) |
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#define MINBLOCK_US 1 |
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struct key_t { |
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char waker[TASK_COMM_LEN]; |
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char target[TASK_COMM_LEN]; |
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u32 wret; |
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u32 tret; |
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}; |
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struct { |
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__uint(type, BPF_MAP_TYPE_HASH); |
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__type(key, struct key_t); |
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__type(value, u64); |
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__uint(max_entries, 10000); |
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} counts SEC(".maps"); |
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struct { |
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__uint(type, BPF_MAP_TYPE_HASH); |
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__type(key, u32); |
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__type(value, u64); |
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__uint(max_entries, 10000); |
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} start SEC(".maps"); |
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struct wokeby_t { |
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char name[TASK_COMM_LEN]; |
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u32 ret; |
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}; |
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struct { |
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__uint(type, BPF_MAP_TYPE_HASH); |
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__type(key, u32); |
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__type(value, struct wokeby_t); |
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__uint(max_entries, 10000); |
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} wokeby SEC(".maps"); |
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struct { |
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__uint(type, BPF_MAP_TYPE_STACK_TRACE); |
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__uint(key_size, sizeof(u32)); |
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__uint(value_size, PERF_MAX_STACK_DEPTH * sizeof(u64)); |
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__uint(max_entries, 10000); |
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} stackmap SEC(".maps"); |
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#define STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP) |
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SEC("kprobe/try_to_wake_up") |
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int waker(struct pt_regs *ctx) |
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{ |
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struct task_struct *p = (void *) PT_REGS_PARM1(ctx); |
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struct wokeby_t woke; |
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u32 pid; |
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pid = _(p->pid); |
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bpf_get_current_comm(&woke.name, sizeof(woke.name)); |
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woke.ret = bpf_get_stackid(ctx, &stackmap, STACKID_FLAGS); |
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bpf_map_update_elem(&wokeby, &pid, &woke, BPF_ANY); |
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return 0; |
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} |
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static inline int update_counts(void *ctx, u32 pid, u64 delta) |
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{ |
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struct wokeby_t *woke; |
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u64 zero = 0, *val; |
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struct key_t key; |
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__builtin_memset(&key.waker, 0, sizeof(key.waker)); |
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bpf_get_current_comm(&key.target, sizeof(key.target)); |
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key.tret = bpf_get_stackid(ctx, &stackmap, STACKID_FLAGS); |
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key.wret = 0; |
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woke = bpf_map_lookup_elem(&wokeby, &pid); |
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if (woke) { |
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key.wret = woke->ret; |
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__builtin_memcpy(&key.waker, woke->name, sizeof(key.waker)); |
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bpf_map_delete_elem(&wokeby, &pid); |
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} |
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val = bpf_map_lookup_elem(&counts, &key); |
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if (!val) { |
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bpf_map_update_elem(&counts, &key, &zero, BPF_NOEXIST); |
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val = bpf_map_lookup_elem(&counts, &key); |
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if (!val) |
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return 0; |
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} |
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(*val) += delta; |
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return 0; |
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} |
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#if 1 |
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/* taken from /sys/kernel/debug/tracing/events/sched/sched_switch/format */ |
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struct sched_switch_args { |
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unsigned long long pad; |
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char prev_comm[16]; |
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int prev_pid; |
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int prev_prio; |
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long long prev_state; |
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char next_comm[16]; |
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int next_pid; |
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int next_prio; |
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}; |
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SEC("tracepoint/sched/sched_switch") |
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int oncpu(struct sched_switch_args *ctx) |
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{ |
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/* record previous thread sleep time */ |
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u32 pid = ctx->prev_pid; |
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#else |
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SEC("kprobe/finish_task_switch") |
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int oncpu(struct pt_regs *ctx) |
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{ |
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struct task_struct *p = (void *) PT_REGS_PARM1(ctx); |
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/* record previous thread sleep time */ |
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u32 pid = _(p->pid); |
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#endif |
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u64 delta, ts, *tsp; |
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ts = bpf_ktime_get_ns(); |
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bpf_map_update_elem(&start, &pid, &ts, BPF_ANY); |
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/* calculate current thread's delta time */ |
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pid = bpf_get_current_pid_tgid(); |
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tsp = bpf_map_lookup_elem(&start, &pid); |
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if (!tsp) |
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/* missed start or filtered */ |
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return 0; |
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delta = bpf_ktime_get_ns() - *tsp; |
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bpf_map_delete_elem(&start, &pid); |
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delta = delta / 1000; |
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if (delta < MINBLOCK_US) |
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return 0; |
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return update_counts(ctx, pid, delta); |
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} |
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char _license[] SEC("license") = "GPL"; |
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u32 _version SEC("version") = LINUX_VERSION_CODE;
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