Lua ports of biosnoop and stacksnoop
diff --git a/tools/biosnoop.lua b/tools/biosnoop.lua
new file mode 100644
index 0000000..ac08897
--- /dev/null
+++ b/tools/biosnoop.lua
@@ -0,0 +1,183 @@
+#!/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 <uapi/linux/ptrace.h>
+#include <linux/blkdev.h>
+
+struct val_t {
+ u32 pid;
+ char name[TASK_COMM_LEN];
+};
+
+struct data_t {
+ u32 pid;
+ u64 rwflag;
+ u64 delta;
+ u64 sector;
+ u64 len;
+ u64 ts;
+ char disk_name[DISK_NAME_LEN];
+ char name[TASK_COMM_LEN];
+};
+
+BPF_HASH(start, struct request *);
+BPF_HASH(infobyreq, struct request *, struct val_t);
+BPF_PERF_OUTPUT(events);
+
+// cache PID and comm by-req
+int trace_pid_start(struct pt_regs *ctx, struct request *req)
+{
+ struct val_t val = {};
+
+ if (bpf_get_current_comm(&val.name, sizeof(val.name)) == 0) {
+ val.pid = bpf_get_current_pid_tgid();
+ infobyreq.update(&req, &val);
+ }
+ return 0;
+}
+
+// time block I/O
+int trace_req_start(struct pt_regs *ctx, struct request *req)
+{
+ u64 ts;
+
+ ts = bpf_ktime_get_ns();
+ start.update(&req, &ts);
+
+ return 0;
+}
+
+// output
+int trace_req_completion(struct pt_regs *ctx, struct request *req)
+{
+ u64 *tsp, delta;
+ u32 *pidp = 0;
+ struct val_t *valp;
+ struct data_t data ={};
+ u64 ts;
+
+ // fetch timestamp and calculate delta
+ tsp = start.lookup(&req);
+ if (tsp == 0) {
+ // missed tracing issue
+ return 0;
+ }
+ ts = bpf_ktime_get_ns();
+ data.delta = ts - *tsp;
+ data.ts = ts / 1000;
+
+ valp = infobyreq.lookup(&req);
+ if (valp == 0) {
+ data.len = req->__data_len;
+ strcpy(data.name,"?");
+ } else {
+ data.pid = valp->pid;
+ data.len = req->__data_len;
+ data.sector = req->__sector;
+ bpf_probe_read(&data.name, sizeof(data.name), valp->name);
+ bpf_probe_read(&data.disk_name, sizeof(data.disk_name),
+ req->rq_disk->disk_name);
+ }
+
+ if (req->cmd_flags & REQ_WRITE) {
+ data.rwflag=1;
+ } else {
+ data.rwflag=0;
+ }
+ events.perf_submit(ctx,&data,sizeof(data));
+ start.delete(&req);
+ infobyreq.delete(&req);
+
+ return 0;
+}
+]]
+
+local ffi = require("ffi")
+
+return function(BPF, utils)
+ local bpf = BPF:new{text=program}
+
+ bpf:attach_kprobe{event="blk_account_io_start", fn_name="trace_pid_start"}
+ bpf:attach_kprobe{event="blk_start_request", fn_name="trace_req_start"}
+ bpf:attach_kprobe{event="blk_mq_start_request", fn_name="trace_req_start"}
+ bpf:attach_kprobe{event="blk_account_io_completion",
+ fn_name="trace_req_completion"}
+
+ print("%-14s %-14s %-6s %-7s %-2s %-9s %-7s %7s" % {"TIME(s)", "COMM", "PID",
+ "DISK", "T", "SECTOR", "BYTES", "LAT(ms)"})
+
+ local rwflg = ""
+ local start_ts = 0
+ local prev_ts = 0
+ local delta = 0
+
+ local function print_event(cpu, event)
+ local val = -1
+ local event_pid = event.pid
+ local event_delta = tonumber(event.delta)
+ local event_sector = tonumber(event.sector)
+ local event_len = tonumber(event.len)
+ local event_ts = tonumber(event.ts)
+ local event_disk_name = ffi.string(event.disk_name)
+ local event_name = ffi.string(event.name)
+
+ if event.rwflag == 1 then
+ rwflg = "W"
+ end
+
+ if event.rwflag == 0 then
+ rwflg = "R"
+ end
+
+ if not event_name:match("%?") then
+ val = event_sector
+ end
+
+ if start_ts == 0 then
+ prev_ts = start_ts
+ end
+
+ if start_ts == 1 then
+ delta = delta + (event_ts - prev_ts)
+ end
+
+ print("%-14.9f %-14.14s %-6s %-7s %-2s %-9s %-7s %7.2f" % {
+ delta / 1000000, event_name, event_pid, event_disk_name, rwflg, val,
+ event_len, event_delta / 1000000})
+
+ prev_ts = event_ts
+ start_ts = 1
+ end
+
+ local TASK_COMM_LEN = 16 -- linux/sched.h
+ local DISK_NAME_LEN = 32 -- linux/genhd.h
+
+ bpf:get_table("events"):open_perf_buffer(print_event, [[
+ struct {
+ uint32_t pid;
+ uint64_t rwflag;
+ uint64_t delta;
+ uint64_t sector;
+ uint64_t len;
+ uint64_t ts;
+ char disk_name[%d];
+ char name[%d];
+ }
+ ]] % {DISK_NAME_LEN, TASK_COMM_LEN})
+ bpf:kprobe_poll_loop()
+end