W dniu 2011-01-26 14:06, John Baldwin pisze:
On Wednesday, January 26, 2011 7:20:34 am Bartosz Stec wrote:
Guys,
could someone explain me this?
# sysctl hw.realmem
hw.realmem: 2139029504
top line shows:
Mem: 32M Active, 35M Inact, 899M Wired, 8392K Cache, 199M Buf, 58M Free
32+35+899+8+199+58 = 1231MB
Shouldn't that sum to all available ram? Or maybe I'm reading it wrong?
This machine has indeed 2GB of ram on board and showed in BIOS.
i386 FreeBSD 8.2-PRERELEASE #16: Mon Jan 17 22:28:53 CET 2011
Cheers.
First, don't include 'buf' as isn't a separate set of RAM, it is only a range
of the virtual address space in the kernel. It used to be relevant when the
buffer cache was separate from the VM page cache, but now it is mostly
irrelevant (arguably it should just be dropped from top output).
Thanks for the explanation. So 1231MB - 199MB Buf and we got about 1GB
of memory instead of 2B.
However, look at what hw.physmem says (and the realmem and availmem lines in
dmesg). realmem is actually not that useful as it is not a count of the
amount of memory, but the address of the highest memory page available. There
can be less memory available than that due to "holes" in the address space for
PCI memory BARs, etc.
OK, here you go:
# sysctl hw | grep mem
hw.physmem: 2125893632
hw.usermem: 1212100608
hw.realmem: 2139029504
hw.pci.host_mem_start: 2147483648
And here's the part of /boot/loader.conf for ZFS tuning which may (or
probably may not) connected to this issue:
vm.kmem_size="1536M"
vm.kmem_size_max="1536M"
vfs.zfs.arc_max="1280M"
--
Bartosz Stec
_______________________________________________
freebsd-stable@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-stable
To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
