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KVM_SWAPINFO(3)       DragonFly Library Functions Manual       KVM_SWAPINFO(3)


NAME

     kvm_getswapinfo -- return swap summary statistics for the system


LIBRARY

     Kernel Data Access Library (libkvm, -lkvm)


SYNOPSIS

     #include <sys/types.h>
     #include <kvm.h>

     int
     kvm_getswapinfo(kvm_t *kd, struct kvm_swap *, int maxswap, int flags);


DESCRIPTION

     The kvm_getswapinfo() function fills an array of kvm_swap structures with
     swap summary information for each swap device, for up to maxswap - 1
     devices.  The number of devices, up to maxswap - 1, is returned.  A grand
     total of all swap devices (including any devices that go beyond maxswap -
     1) is returned in one additional array entry.  This entry is not counted
     in the return value.  Thus, if you specify a maxswap value of 1, the
     function will typically return the value 0 and the single kvm_swap
     structure will be filled with the grand total over all swap devices.  The
     grand total is calculated from all available swap devices whether or not
     you made room for them all in the array.  The grand total is returned.

     The flags argument is currently unused and must be passed as 0.

     If an error occurs, -1 is returned.

     Each swap partition and the grand total is summarized in the kvm_swap
     structure.  This structure contains the following fields:

           char ksw_devname[];
           u_int ksw_total;
           u_int ksw_used;
           int ksw_flags;

     Values are in PAGE_SIZE'd chunks (see getpagesize(3)).  ksw_flags
     contains a copy of the swap device flags.


WARNING

     At the current juncture this structure can only represent up to 16TB of
     swap per device, and the totalizer field will overflow at 16TB (4TB per
     device).  The fields need to be converted to long's.


CACHING

     This function caches the nlist values for various kernel variables which
     it reuses in successive calls.  You may call the function with kd == NULL
     to clear the cache.


DIAGNOSTICS

     If the load average was unobtainable, -1 is returned; otherwise, the
     number of swap devices actually retrieved is returned.

     If the name of the swap device does not fit in the static char buffer in
     the structure, it is truncated.  The buffer is always zero terminated.


SEE ALSO

     kvm(3)

DragonFly 4.7                  January 22, 1999                  DragonFly 4.7

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