#!/usr/bin/env bpftrace /* * biostacks - Show disk I/O latency with initialization stacks. * * See BPF Performance Tools, Chapter 9, for an explanation of this tool. * * Copyright (c) 2019 Brendan Gregg. * Licensed under the Apache License, Version 2.0 (the "License"). * This was originally created for the BPF Performance Tools book * published by Addison Wesley. ISBN-13: 9780136554820 * When copying or porting, include this comment. * * 19-Mar-2019 Brendan Gregg Created this. */ BEGIN { printf("Tracing block I/O with init stacks. Hit Ctrl-C to end.\n"); } kprobe:blk_account_io_start, kprobe:__blk_account_io_start { @reqstack[arg0] = kstack; @reqts[arg0] = nsecs; } kprobe:blk_start_request, kprobe:blk_mq_start_request /@reqts[arg0]/ { @usecs[@reqstack[arg0]] = hist(nsecs - @reqts[arg0]); delete(@reqstack[arg0]); delete(@reqts[arg0]); } END { clear(@reqstack); clear(@reqts); }