Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 27 Jan 1998 02:03:21 -0500 (EST)
From:      "John S. Dyson" <dyson@FreeBSD.ORG>
To:        joelh@gnu.org
Cc:        mike@smith.net.au, dag-erli@ifi.uio.no, hackers@FreeBSD.ORG
Subject:   Re: File I/O in kernel land (was: Re: 2nd warning: 2.2.6 BETA begins in 10 days!)
Message-ID:  <199801270703.CAA27777@dyson.iquest.net>
In-Reply-To: <199801270637.AAA04478@detlev.UUCP> from Joel Ray Holveck at "Jan 27, 98 00:37:51 am"

next in thread | previous in thread | raw e-mail | index | archive | help
Joel Ray Holveck said:
> 
> My real concern is holding on to lots of dynamically allocated kernel
> memory, which is something I can't see getting around without the
> screen saver doing file I/O.  In Linux, dynamic kernel memory was a
> precious resource.  Is it not so in FreeBSD?
> 
In FreeBSD, the kernel address space should be carefully used, but
it is not any more precious than statically allocated kernel memory.
We are currently limited to a little less than 256MB kernel virtual
size.  Almost everything like buffer space, and temporary type mappings, etc.
are dynamically allocated, and most of the buffer space isn't normally
mapped anyway.  That KVA size is almost always adequate
for workstation applications, for almost any memory size.  However, for
server apps, you can rebuild the kernel with a few mods so that you
can run with KVA size of 512MB or 1GB (but isn't needed, except on machines
with lots and lots of TCP connections, etc.)

-- 
John                  | Never try to teach a pig to sing,
dyson@freebsd.org     | it just makes you look stupid,
jdyson@nc.com         | and it irritates the pig.



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199801270703.CAA27777>