On Tue, Sep 21, 2010 at 9:56 PM, Steven Bellovin <[email protected]> wrote: > > On Sep 21, 2010, at 5:51 34PM, matthew sporleder wrote: > >> On Tue, Sep 21, 2010 at 5:38 PM, Matthew Mondor >> <[email protected]> wrote: >>> On Sun, 19 Sep 2010 15:13:59 -0400 >>> matthew sporleder <[email protected]> wrote: >>> >>>> So I've recently been exploring a pretty common mystery on netbsd >>>> machines- where is my memory? >>> >>> I'm not sure this answers your questions, but the dmesg of a system >>> here (also with 2GB RAM) has: >>> >>> total memory = 2047 MB >>> avail memory = 1999 MB >>> >>> I assume some pages are reserved and/or used for PMMU tables, etc... >>> -- >>> Matt >>> >> >> total memory = 256 MB >> avail memory = 239 MB >> >> So that works well with the vmstat -s numbers. However, that still >> doesn't really explain where that memory is. >> >> I guess top should be patched or something to reflect the vmstat -s >> numbers instead of whatever it's currently using. >> >> Would you mind looking at vmstat -s and see if you're missing 48MB? > > Some graphics chips, especially on lower-end machines, use main memory, thus > making it unavailable to the CPU. >
On my soekris with no video card: total memory = 127 MB avail memory = 113 MB Oddly on this box physmem and usermem are the same: hw.physmem64 = 133820416 hw.usermem64 = 133820416 vmstat -s shows: 119787520 bytes managed == avail memory from dmesg. So can I get a hint on where dmesg is calculating these two numbers and where that allocation goes?
