// SPDX-License-Identifier: GPL-2.0 // Copyright (c) 2020 Wenbo Zhang #include #include #include #include #include "cpudist.h" #include "bits.bpf.h" #include "core_fixes.bpf.h" #define TASK_RUNNING 0 const volatile bool targ_per_process = false; const volatile bool targ_per_thread = false; const volatile bool targ_offcpu = false; const volatile bool targ_ms = false; const volatile pid_t targ_tgid = -1; struct { __uint(type, BPF_MAP_TYPE_HASH); __type(key, u32); __type(value, u64); } start SEC(".maps"); static struct hist initial_hist; struct { __uint(type, BPF_MAP_TYPE_HASH); __type(key, u32); __type(value, struct hist); } hists SEC(".maps"); static __always_inline void store_start(u32 tgid, u32 pid, u64 ts) { if (targ_tgid != -1 && targ_tgid != tgid) return; bpf_map_update_elem(&start, &pid, &ts, 0); } static __always_inline void update_hist(struct task_struct *task, u32 tgid, u32 pid, u64 ts) { u64 delta, *tsp, slot; struct hist *histp; u32 id; if (targ_tgid != -1 && targ_tgid != tgid) return; tsp = bpf_map_lookup_elem(&start, &pid); if (!tsp || ts < *tsp) return; if (targ_per_process) id = tgid; else if (targ_per_thread) id = pid; else id = -1; histp = bpf_map_lookup_elem(&hists, &id); if (!histp) { bpf_map_update_elem(&hists, &id, &initial_hist, 0); histp = bpf_map_lookup_elem(&hists, &id); if (!histp) return; bpf_probe_read_kernel_str(&histp->comm, sizeof(task->comm), task->comm); } delta = ts - *tsp; if (targ_ms) delta /= 1000000; else delta /= 1000; slot = log2l(delta); if (slot >= MAX_SLOTS) slot = MAX_SLOTS - 1; __sync_fetch_and_add(&histp->slots[slot], 1); } SEC("tp_btf/sched_switch") int BPF_PROG(sched_switch, bool preempt, struct task_struct *prev, struct task_struct *next) { u32 prev_tgid = prev->tgid, prev_pid = prev->pid; u32 tgid = next->tgid, pid = next->pid; u64 ts = bpf_ktime_get_ns(); if (targ_offcpu) { store_start(prev_tgid, prev_pid, ts); update_hist(next, tgid, pid, ts); } else { if (get_task_state(prev) == TASK_RUNNING) update_hist(prev, prev_tgid, prev_pid, ts); store_start(tgid, pid, ts); } return 0; } char LICENSE[] SEC("license") = "GPL";