Subject: default vnodes in the system
To: None <>
From: matthew green <>
List: tech-kern
Date: 06/02/2003 18:34:18
hi folks.

clearly, netbsd allocates far too few vnodes by default in nearly
all cases.  this is the current base definition:

	#define       NVNODE  (NPROC + NTEXT + 100)

adjusted to about 0.5% of ram (but not less) if NVNODE isn't set
in the kernel config file.  this 0.5% of ram value was chosen(?)
by jarmoir (i guess) from this (kern/init_main.c):

	revision 1.175
	date: 2000/07/06 09:51:55;  author: jdolecek;  state: Exp;  lines: +15 -1
	adjust maximum number of vnodes in vnode cache according
	to machine memory size upon boot if the number has not been specified
	explicitly in kernel config - at this moment, 0.5% of system
	memory is used for vnodes (but minimum NVNODE vnodes)

i think 0.5% is too few.  (was this before UBC?  0.5% probably
made more sense back then...)  i'd pick something between 1% and
2% probably...

what do people think?  perhaps as a first step raising it to 1%
would alleviate most of the problem[*]


[*] the problem being that for larger-RAM systems there are hundreds
of MB's of free ram but vnodes being constantly recycled and page
cache never being able to "fill" ram.