Subject: default vnodes in the system
To: None <tech-kern@netbsd.org>
From: matthew green <mrg@eterna.com.au>
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[*]
.mrg.
[*] 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.