#!/usr/sbin/dtrace -s /* * fsrw.d - file system read/write event tracing. * Written using DTrace (Solaris 10 3/05) * * This traces file related activity: system call reads and writes, * vnode logical read and writes (fop), and disk I/O. It can be used * to examine the behaviour of each I/O layer, from the syscall * interface to what the disk is doing. Behaviour such as read-ahead, and * max I/O size breakup can be observed. * * $Id: fsrw.d,v 1.1.1.1 2015/09/30 22:01:09 christos Exp $ * * USAGE: fsrw.d * * FIELDS: * Event Traced event (see EVENTS below) * Device Device, for disk I/O * RW Either Read or Write * Size Size of I/O in bytes * Offset Offset of I/O in kilobytes * Path Path to file on disk * * EVENTS: * sc-read System call read * sc-write System call write * fop_read Logical read * fop_write Logical write * disk_io Physical disk I/O * disk_ra Physical disk I/O, read ahead * * The events are drawn with a level of indentation, which can sometimes * help identify related events. * * SEE ALSO: fspaging.d * * IDEA: Richard McDougall, Solaris Internals 2nd Ed, FS Chapter. * * COPYRIGHT: Copyright (c) 2006 Brendan Gregg. * * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License, Version 1.0 only * (the "License"). You may not use this file except in compliance * with the License. * * You can obtain a copy of the license at Docs/cddl1.txt * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * CDDL HEADER END * * ToDo: readv() * * 20-Mar-2006 Brendan Gregg Created this. * 23-Apr-2006 " " Last update. */ #pragma D option quiet #pragma D option switchrate=10hz dtrace:::BEGIN { printf("%-12s %10s %2s %8s %6s %s\n", "Event", "Device", "RW", "Size", "Offset", "Path"); } syscall::*read:entry, syscall::*write*:entry { /* * starting with a file descriptior, dig out useful info * from the corresponding file_t and vnode_t. */ this->filistp = curthread->t_procp->p_user.u_finfo.fi_list; this->ufentryp = (uf_entry_t *)((uint64_t)this->filistp + (uint64_t)arg0 * (uint64_t)sizeof (uf_entry_t)); this->filep = this->ufentryp->uf_file; self->offset = this->filep->f_offset; this->vnodep = this->filep != 0 ? this->filep->f_vnode : 0; self->vpath = this->vnodep ? (this->vnodep->v_path != 0 ? cleanpath(this->vnodep->v_path) : "") : ""; /* only trace activity to regular files and directories, as */ self->sc_trace = this->vnodep ? this->vnodep->v_type == VREG || this->vnodep->v_type == VDIR ? 1 : 0 : 0; } syscall::*read:entry /self->sc_trace/ { printf("sc-%-9s %10s %2s %8d %6d %s\n", probefunc, ".", "R", (int)arg2, self->offset / 1024, self->vpath); } syscall::*write*:entry /self->sc_trace/ { printf("sc-%-9s %10s %2s %8d %6d %s\n", probefunc, ".", "W", (int)arg2, self->offset / 1024, self->vpath); } syscall::*read:return, syscall::*write*:return { self->vpath = 0; self->offset = 0; self->sc_trace = 0; } fbt::fop_read:entry, fbt::fop_write:entry /self->sc_trace && args[0]->v_path/ { printf(" %-10s %10s %2s %8d %6d %s\n", probefunc, ".", probefunc == "fop_read" ? "R" : "W", args[1]->uio_resid, args[1]->_uio_offset._f / 1024, cleanpath(args[0]->v_path)); } fbt:ufs:ufs_getpage_ra:entry { /* fetch the real offset (file_t is unaware of this) */ self->ra_offset = ((inode_t *)args[0]->v_data)->i_nextrio; self->read_ahead = 1; } fbt:ufs:ufs_getpage_ra:return { self->read_ahead = 0; self->ra_offset = 0; } io::bdev_strategy:start { this->offset = self->read_ahead ? self->ra_offset : args[2]->fi_offset; printf(" %-8s %10s %2s %8d %6d %s\n", self->read_ahead ? "disk_ra" : "disk_io", args[1]->dev_statname, args[0]->b_flags & B_READ ? "R" : "W", args[0]->b_bcount, this->offset / 1024, args[2]->fi_pathname); /* * it would seem to make sense to only trace disk events during * an fop event, easily coded with a self->fop_trace flag. However * writes are asynchronous to the fop_write calls (they are flushed * at some later time), and so this approach will miss tracing * most of the disk writes. */ }