#!/usr/bin/env bcc-lua --[[ Copyright 2016 GitHub, Inc Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. ]] local program = [[ #include #include #define MINBLOCK_US 1 struct key_t { char name[TASK_COMM_LEN]; int stack_id; }; BPF_HASH(counts, struct key_t); BPF_HASH(start, u32); BPF_STACK_TRACE(stack_traces, 10240); int oncpu(struct pt_regs *ctx, struct task_struct *prev) { u32 pid; u64 ts, *tsp; // record previous thread sleep time if (FILTER) { pid = prev->pid; ts = bpf_ktime_get_ns(); start.update(&pid, &ts); } // calculate current thread's delta time pid = bpf_get_current_pid_tgid(); tsp = start.lookup(&pid); if (tsp == 0) return 0; // missed start or filtered u64 delta = bpf_ktime_get_ns() - *tsp; start.delete(&pid); delta = delta / 1000; if (delta < MINBLOCK_US) return 0; // create map key u64 zero = 0, *val; struct key_t key = {}; int stack_flags = 0; /* if (!(prev->flags & PF_KTHREAD)) stack_flags |= BPF_F_USER_STACK; */ bpf_get_current_comm(&key.name, sizeof(key.name)); key.stack_id = stack_traces.get_stackid(ctx, stack_flags); val = counts.lookup_or_try_init(&key, &zero); if (val) { (*val) += delta; } return 0; } ]] return function(BPF, utils) local ffi = require("ffi") local parser = utils.argparse("offcputime", "Summarize off-cpu time") parser:flag("-u --user-only") parser:option("-p --pid"):convert(tonumber) parser:flag("-f --folded") parser:option("-d --duration", "duration to trace for", 9999999):convert(tonumber) local args = parser:parse() local ksym = BPF.SymbolCache() local filter = "1" local MAXDEPTH = 20 if args.pid then filter = "pid == %d" % args.pid elseif args.user_only then filter = "!(prev->flags & PF_KTHREAD)" end local text = program:gsub("FILTER", filter) local b = BPF:new{text=text} b:attach_kprobe{event="finish_task_switch", fn_name="oncpu"} if BPF.num_open_kprobes() == 0 then print("no functions matched. quitting...") return end print("Sleeping for %d seconds..." % args.duration) pcall(utils.posix.sleep, args.duration) print("Tracing...") local counts = b:get_table("counts") local stack_traces = b:get_table("stack_traces") for k, v in counts:items() do for addr in stack_traces:walk(tonumber(k.stack_id)) do print(" %-16p %s" % {addr, ksym:resolve(addr)}) end print(" %-16s %s" % {"-", ffi.string(k.name)}) print(" %d\n" % tonumber(v)) end end