1.\" Copyright (C) 1999 Matthew Dillon. All rights reserved. 2.\" 3.\" Redistribution and use in source and binary forms, with or without 4.\" modification, are permitted provided that the following conditions 5.\" are met: 6.\" 1. Redistributions of source code must retain the above copyright 7.\" notice, this list of conditions and the following disclaimer. 8.\" 2. Redistributions in binary form must reproduce the above copyright 9.\" notice, this list of conditions and the following disclaimer in the 10.\" documentation and/or other materials provided with the distribution. 11.\" 12.\" THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND 13.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 14.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 15.\" ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE 16.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 17.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 18.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 19.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 20.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 21.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 22.\" SUCH DAMAGE. 23.\" 24.\" $FreeBSD$ 25.\" 26.Dd January 2, 2017 27.Dt KVM_SWAPINFO 3 28.Os 29.Sh NAME 30.Nm kvm_getswapinfo 31.Nd return swap summary statistics for the system 32.Sh LIBRARY 33.Lb libkvm 34.Sh SYNOPSIS 35.In kvm.h 36.Ft int 37.Fn kvm_getswapinfo "kvm_t *kd" "struct kvm_swap *" "int maxswap" "int flags" 38.Sh DESCRIPTION 39The 40.Fn kvm_getswapinfo 41function fills an array of 42.Vt kvm_swap 43structures with swap summary 44information for each swap device, for up to 45.Fa maxswap 46\- 1 devices. 47The number of devices, up to 48.Fa maxswap 49\- 1, is returned. 50A grand 51total of all swap devices (including any devices that go beyond 52.Fa maxswap 53\- 1) is returned in one additional array entry. 54This 55entry is not counted in the return value. 56Thus, if you specify a 57.Fa maxswap 58value of 1, the function will typically return the 59value 0 and the single 60.Vt kvm_swap 61structure will be filled with 62the grand total over all swap devices. 63The grand total is calculated 64from all available swap devices whether or not you made room 65for them all in the array. 66The grand total is returned. 67.Pp 68The flags argument is currently unused and must be passed as 0. 69.Pp 70If an error occurs, -1 is returned. 71.Pp 72Each swap partition and the grand total is summarized in the 73.Vt kvm_swap 74structure. 75This structure contains the following fields: 76.Pp 77.Bl -item -offset indent -compact 78.It 79.Va char ksw_devname[] ; 80.It 81.Va u_int ksw_total ; 82.It 83.Va u_int ksw_used ; 84.It 85.Va int ksw_flags ; 86.El 87.Pp 88Values are in 89.Dv PAGE_SIZE Ns 'd 90chunks (see 91.Xr getpagesize 3 ) . 92.Va ksw_flags 93contains 94a copy of the swap device flags. 95.Sh CACHING 96This function caches the nlist values for various kernel variables which 97it reuses in successive calls. 98You may call the function with 99.Fa kd 100== 101.Dv NULL 102to clear the cache. 103.Sh DIAGNOSTICS 104If the load average was unobtainable, \-1 is returned; otherwise, 105the number of swap devices actually retrieved is returned. 106.Pp 107If the name of the swap device does not fit in the static char buffer 108in the structure, it is truncated. 109The buffer is always zero terminated. 110.Sh SEE ALSO 111.Xr kvm 3 112