#!/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);
}
Mini Shell