158550067SMark Murray.\" Copyright (c) 2000 Mark R V Murray 258550067SMark Murray.\" All rights reserved. 358550067SMark Murray.\" 458550067SMark Murray.\" Redistribution and use in source and binary forms, with or without 558550067SMark Murray.\" modification, are permitted provided that the following conditions 658550067SMark Murray.\" are met: 758550067SMark Murray.\" 1. Redistributions of source code must retain the above copyright 858550067SMark Murray.\" notice, this list of conditions and the following disclaimer. 958550067SMark Murray.\" 2. Redistributions in binary form must reproduce the above copyright 1058550067SMark Murray.\" notice, this list of conditions and the following disclaimer in the 1158550067SMark Murray.\" documentation and/or other materials provided with the distribution. 1258550067SMark Murray.\" 1358550067SMark Murray.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 1458550067SMark Murray.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1558550067SMark Murray.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1658550067SMark Murray.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 1758550067SMark Murray.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 1858550067SMark Murray.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 1958550067SMark Murray.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2058550067SMark Murray.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2158550067SMark Murray.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2258550067SMark Murray.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2358550067SMark Murray.\" SUCH DAMAGE. 2458550067SMark Murray.\" 25d8ea2a49SJung-uk Kim.Dd March 15, 2011 2652f1d68fSRuslan Ermilov.Dt GET_CYCLECOUNT 9 2758550067SMark Murray.Os 2858550067SMark Murray.Sh NAME 2923257a00SChad David.Nm get_cyclecount 3058550067SMark Murray.Nd get the CPU's fast counter register contents 3158550067SMark Murray.Sh SYNOPSIS 3232eef9aeSRuslan Ermilov.In sys/param.h 337d6ad52aSMark Murray.In sys/systm.h 3432eef9aeSRuslan Ermilov.In machine/cpu.h 356b99842aSEd Schouten.Ft uint64_t 3623257a00SChad David.Fn get_cyclecount "void" 3758550067SMark Murray.Sh DESCRIPTION 3858550067SMark MurrayThe 3923257a00SChad David.Fn get_cyclecount 4052f1d68fSRuslan Ermilovfunction uses a register 4158550067SMark Murrayavailable in most modern CPUs 4258550067SMark Murrayto return a value 4358550067SMark Murraythat is monotonically increasing 4458550067SMark Murrayinside each CPU. 4558550067SMark Murray.Pp 4652f1d68fSRuslan ErmilovOn SMP systems, 4758550067SMark Murraythere will be a number of 4858550067SMark Murrayseparate monotonic sequences, 4958550067SMark Murrayone for each CPU running. 5058550067SMark MurrayThe value in the SMP case is 5158550067SMark Murrayselected from one of these sequences, 5258550067SMark Murraydependent on which CPU 5358550067SMark Murraywas scheduled to service the request. 5458550067SMark Murray.Pp 5552f1d68fSRuslan ErmilovThe speed and the maximum value 5658550067SMark Murrayof each counter 57e986850fSJens Schweikhardtis CPU-dependent. 5858550067SMark MurraySome CPUs 5958550067SMark Murray(such as the 6058550067SMark Murray.Tn Intel 611f25113fSJohn Baldwin80486) 6258550067SMark Murraydo not have such a register, 6358550067SMark Murrayso 6423257a00SChad David.Fn get_cyclecount 6558550067SMark Murrayon these platforms 66d8ea2a49SJung-uk Kimreturns a (monotonic) combination of numbers 6758550067SMark Murrayrepresented by the 6858550067SMark Murraystructure returned by 6995894120SRuslan Ermilov.Xr binuptime 9 . 7058550067SMark Murray.Pp 7158550067SMark MurrayThe 72c26c3874SJung-uk Kim.Tn AMD64 73c26c3874SJung-uk Kimand 74c26c3874SJung-uk Kim.Tn Intel 64 75d8ea2a49SJung-uk Kimprocessors use the 7658550067SMark Murray.Li TSC 7758550067SMark Murrayregister. 7858550067SMark Murray.Sh SEE ALSO 7995894120SRuslan Ermilov.Xr binuptime 9 8058550067SMark Murray.Sh HISTORY 8158550067SMark MurrayThe 8223257a00SChad David.Fn get_cyclecount 8358550067SMark Murrayfunction first appeared in 84ae9fd628SRuslan Ermilov.Fx 5.0 . 8558550067SMark Murray.Sh AUTHORS 8658550067SMark MurrayThis manual page was written by 87*8a7314fcSBaptiste Daroussin.An Mark Murray Aq Mt markm@FreeBSD.org . 88