taglinefilesource code
freeswap283fs/proc/array.ci.totalswap, i.totalswap-i.freeswap, i.freeswap);
freeswap302fs/proc/array.ci.freeswap >> 10);
freeswap77include/linux/kernel.hunsigned long freeswap;    /* swap space still available */
freeswap543mm/swapfile.cval->freeswap = val->totalswap = 0;
freeswap552mm/swapfile.c++val->freeswap;
freeswap557mm/swapfile.cval->freeswap <<= PAGE_SHIFT;