#!/usr/bin/env bpftrace
/*
 * xfsdist	Summarize XFS operation latency.
 *		For Linux, uses bpftrace and eBPF.
 *
 * This traces four common file system calls: read, write, open, and fsync.
 * It can be customized to trace more if desired.
 *
 * USAGE: xfsdist.bt
 *
 * This is a bpftrace version of the bcc tool of the same name.
 *
 * Copyright 2018 Netflix, Inc.
 * Licensed under the Apache License, Version 2.0 (the "License")
 *
 * 08-Sep-2018	Brendan Gregg	Created this.
 */

config = { missing_probes = "ignore" }

BEGIN
{
	printf("Tracing XFS operation latency... Hit Ctrl-C to end.\n");
}

kprobe:xfs_file_read_iter,
kprobe:xfs_file_write_iter,
kprobe:xfs_file_open,
kprobe:xfs_file_fsync
{
	@start[tid] = nsecs;
	@name[tid] = func;
}

kretprobe:xfs_file_read_iter,
kretprobe:xfs_file_write_iter,
kretprobe:xfs_file_open,
kretprobe:xfs_file_fsync
/@start[tid]/
{
	@us[@name[tid]] = hist((nsecs - @start[tid]) / 1000);
	delete(@start[tid]);
	delete(@name[tid]);
}

END
{
	clear(@start);
	clear(@name);
}