tuning hints for PAE

[Daniel Lang]

Hi,

Scott Long wrote on Thu, Jul 15, 2004 at 01:00:38PM -0600:
[..]
> bash$ sysctl -a |grep vnode
> 
> kern.maxvnodes: 17806
>        vnodes    21     5K      5K      145  16,32,64,128,256
> kern.minvnodes: 4451
> vm.stats.vm.v_vnodein: 3930
> vm.stats.vm.v_vnodeout: 0
> vm.stats.vm.v_vnodepgsin: 25583
> vm.stats.vm.v_vnodepgsout: 0
> vfs.numvnodes: 16133
> vfs.wantfreevnodes: 25
> vfs.freevnodes: 8096
> debug.sizeof.vnode: 260
> 
> The indented line is from kern.malloc and gives you an
> estimate of how much memory is being consumed by the
> vnode pool.

I see, ok, sysctl kern.malloc seems to be exactly the 
same as vmstat -m.

This does not appear to consume a lot of memory anyway, hmmm.
My values are the following (with adjusted maxvnodes):
[..]
kern.maxvnodes: 64000
       vnodes    35     7K      7K      166  16,32,64,128,256
kern.minvnodes: 52958
vm.stats.vm.v_vnodein: 568488
vm.stats.vm.v_vnodeout: 1
vm.stats.vm.v_vnodepgsin: 1384470
vm.stats.vm.v_vnodepgsout: 1
vfs.numvnodes: 190867
vfs.wantfreevnodes: 25
vfs.freevnodes: 135112
debug.sizeof.vnode: 264
[..]

So the actual consumed memory (7k ?) appears neglectible.
However, kern.minvnodes has nearly reached the now upper limit,
so maybe trimming maxvnodes to 64000 was maybe too small,
and the saved space appears not worth the effort?

I will bump it up a bit more...

What about the 35 vnodes "In Use" (reported by kern.malloc) but 
vfs.numvnodes: 190867, I am not sure how to interpret these
values....

As far as I understand it, a vnode is a kernel data-structure 
referring to a file-like entity (file, directory, socket, pipe, etc).
So there are obviously much more in use than 35. 190867 appears
too much, for ~ 400 active processes. Even if there are many 
filedescriptors open by each process, it is probably much less than 500
per process. But maybe if these include all cached vnodes, so
all vnodes which have been in use in the past, it could fit.

Sorry for being not too educated about this really basic
UNIX concept. :-}

Cheers,
 Daniel
-- 
IRCnet: Mr-Spock     - Agartim billiard bumba m'abdul in papejim twista 
-  rumba rock n rolla. Leik'ab mai. Spirzon Heroin se'osit gaula.     -
               - Marijuana esit gaula. Haschisch. Opis. - 
 Daniel Lang * dl at leo.org * +49 89 289 18532 * http://www.leo.org/~dl/