Alexey Ivanov | cc01a9c | 2019-01-16 09:50:46 -0800 | [diff] [blame] | 1 | #!/usr/bin/python |
Brendan Gregg | bea3430 | 2016-02-13 21:07:23 -0800 | [diff] [blame] | 2 | # @lint-avoid-python-3-compatibility-imports |
| 3 | # |
| 4 | # mdflush Trace md flush events. |
| 5 | # For Linux, uses BCC, eBPF. |
| 6 | # |
| 7 | # Todo: add more details of the flush (latency, I/O count). |
| 8 | # |
| 9 | # Copyright 2016 Netflix, Inc. |
| 10 | # Licensed under the Apache License, Version 2.0 (the "License") |
| 11 | # |
| 12 | # 13-Feb-2015 Brendan Gregg Created this. |
| 13 | |
| 14 | from __future__ import print_function |
| 15 | from bcc import BPF |
| 16 | from time import strftime |
Brendan Gregg | bea3430 | 2016-02-13 21:07:23 -0800 | [diff] [blame] | 17 | |
| 18 | # load BPF program |
| 19 | b = BPF(text=""" |
| 20 | #include <uapi/linux/ptrace.h> |
| 21 | #include <linux/sched.h> |
| 22 | #include <linux/genhd.h> |
Sasha Goldshtein | d11179d | 2017-02-13 18:46:24 -0500 | [diff] [blame] | 23 | #include <linux/bio.h> |
Brendan Gregg | bea3430 | 2016-02-13 21:07:23 -0800 | [diff] [blame] | 24 | |
| 25 | struct data_t { |
| 26 | u64 pid; |
| 27 | char comm[TASK_COMM_LEN]; |
| 28 | char disk[DISK_NAME_LEN]; |
| 29 | }; |
| 30 | BPF_PERF_OUTPUT(events); |
| 31 | |
| 32 | int kprobe__md_flush_request(struct pt_regs *ctx, void *mddev, struct bio *bio) |
| 33 | { |
| 34 | struct data_t data = {}; |
Hengqi Chen | f0a0dc7 | 2021-05-20 22:49:25 +0800 | [diff] [blame] | 35 | u32 pid = bpf_get_current_pid_tgid() >> 32; |
Brendan Gregg | bea3430 | 2016-02-13 21:07:23 -0800 | [diff] [blame] | 36 | data.pid = pid; |
| 37 | bpf_get_current_comm(&data.comm, sizeof(data.comm)); |
Paul Chaignon | 3ffc80e | 2017-10-23 21:22:38 +0200 | [diff] [blame] | 38 | /* |
| 39 | * The following deals with a kernel version change (in mainline 4.14, although |
| 40 | * it may be backported to earlier kernels) with how the disk name is accessed. |
| 41 | * We handle both pre- and post-change versions here. Please avoid kernel |
| 42 | * version tests like this as much as possible: they inflate the code, test, |
| 43 | * and maintenance burden. |
| 44 | */ |
| 45 | #ifdef bio_dev |
Paul Chaignon | f86f7e8 | 2018-06-14 02:20:03 +0200 | [diff] [blame] | 46 | struct gendisk *bi_disk = bio->bi_disk; |
Paul Chaignon | 3ffc80e | 2017-10-23 21:22:38 +0200 | [diff] [blame] | 47 | #else |
Paul Chaignon | f86f7e8 | 2018-06-14 02:20:03 +0200 | [diff] [blame] | 48 | struct gendisk *bi_disk = bio->bi_bdev->bd_disk; |
Paul Chaignon | 3ffc80e | 2017-10-23 21:22:38 +0200 | [diff] [blame] | 49 | #endif |
Sumanth Korikkar | 7f6066d | 2020-05-20 10:49:56 -0500 | [diff] [blame] | 50 | bpf_probe_read_kernel(&data.disk, sizeof(data.disk), bi_disk->disk_name); |
Brendan Gregg | bea3430 | 2016-02-13 21:07:23 -0800 | [diff] [blame] | 51 | events.perf_submit(ctx, &data, sizeof(data)); |
| 52 | return 0; |
| 53 | } |
| 54 | """) |
| 55 | |
Brendan Gregg | bea3430 | 2016-02-13 21:07:23 -0800 | [diff] [blame] | 56 | # header |
| 57 | print("Tracing md flush requests... Hit Ctrl-C to end.") |
xingfeng2510 | 03e4948 | 2022-03-17 13:07:16 +0800 | [diff] [blame] | 58 | print("%-8s %-7s %-16s %s" % ("TIME", "PID", "COMM", "DEVICE")) |
Brendan Gregg | bea3430 | 2016-02-13 21:07:23 -0800 | [diff] [blame] | 59 | |
| 60 | # process event |
| 61 | def print_event(cpu, data, size): |
Xiaozhou Liu | 51d62d3 | 2019-02-15 13:03:05 +0800 | [diff] [blame] | 62 | event = b["events"].event(data) |
xingfeng2510 | 03e4948 | 2022-03-17 13:07:16 +0800 | [diff] [blame] | 63 | print("%-8s %-7d %-16s %s" % (strftime("%H:%M:%S"), event.pid, |
jeromemarchand | b96ebcd | 2018-10-10 01:58:15 +0200 | [diff] [blame] | 64 | event.comm.decode('utf-8', 'replace'), |
| 65 | event.disk.decode('utf-8', 'replace'))) |
Brendan Gregg | bea3430 | 2016-02-13 21:07:23 -0800 | [diff] [blame] | 66 | |
| 67 | # read events |
| 68 | b["events"].open_perf_buffer(print_event) |
| 69 | while 1: |
Jerome Marchand | 5167127 | 2018-12-19 01:57:24 +0100 | [diff] [blame] | 70 | try: |
| 71 | b.perf_buffer_poll() |
| 72 | except KeyboardInterrupt: |
| 73 | exit() |