Date: Thu, 19 Apr 2001 05:55:23 -0700 From: Alfred Perlstein <bright@wintelcom.net> To: Maxim Sobolev <sobomax@FreeBSD.org> Cc: Doug Barton <DougB@DougBarton.net>, Matt Dillon <dillon@earth.backplane.com>, "'current@freebsd.org'" <current@FreeBSD.org> Subject: Re: FW: Filesystem gets a huge performance boost Message-ID: <20010419055523.G976@fw.wintelcom.net> In-Reply-To: <3ADEDE2F.573C20A1@FreeBSD.org>; from sobomax@FreeBSD.org on Thu, Apr 19, 2001 at 03:46:39PM %2B0300 References: <200104161634.f3GGYZs11356@aslan.scsiguy.com> <200104162146.f3GLkGT82369@earth.backplane.com> <3ADBF9FA.9D1C4DB4@DougBarton.net> <20010417011335.V976@fw.wintelcom.net> <3ADC0221.32127C39@DougBarton.net> <3ADEDE2F.573C20A1@FreeBSD.org>
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* Maxim Sobolev <sobomax@FreeBSD.org> [010419 05:48] wrote:
> Doug Barton wrote:
>
> > Alfred Perlstein wrote:
> >
> > > I'm figuring the only time when it may be a problem is on machines
> > > with a small amount of memory. Since memory is cheap, I plan on
> > > turning it on within the next couple of days unless a stability
> > > issue comes up.
> > >
> > > I'll leave it to those people with low memory to remember to turn
> > > it off.
> >
> > OK... this brings up the question of what other cool optimizations are
> > there that may have been disabled in the past for reasons that are no
> > longer pertinent? It might be worthwhile to create an /etc/sysctl.conf file
> > with commented out examples of configurations for various systems. For
> > example,
> >
> > # For more modern systems that have a reasonable amount of RAM
> > #vfs.vmiodirenable=1
> >
> > # Low memory systems
> >
> > # Systems that need lots of randomness
> >
> > # Low resource systems that need less randomness
> >
> > # Super high performance TCP options for various situations
> >
> > .... etc. I'm sure y'all can come up with more.
> >
> > It might also be desirable to put these in etc/defautls/rc.conf, but I
> > think something of this nature might be better suited in a freer format.
>
> What do you think about attached patch?
I think it's a step in the right direction, however
vmiodirenable != dirpref
vmiodirenable =
Enable the use of the vm subsystem to back UFS directory memory
requirements, because of the amount of wasted memory this causes
it's not advised for machines with less than 64MB of ram, but on
machines with more than 64MB it can provide a substantial benifit
related to directory caching.
dirpref =
A new allocation policy that can substantially speed up metadata
operations, it's enabled by default once the modifications are
put into -stable, so there probably won't be a sysctl for it. :)
The real fix would be to automagically enable it on machines with
> 64megs of ram.
>
> -Maxim
>
> Index: Makefile
> ===================================================================
> RCS file: /home/ncvs/src/etc/Makefile,v
> retrieving revision 1.248
> diff -d -u -r1.248 Makefile
> --- Makefile 2001/03/29 14:02:59 1.248
> +++ Makefile 2001/04/19 12:44:09
> @@ -15,8 +15,8 @@
> printcap profile protocols \
> rc rc.atm rc.devfs rc.diskless1 rc.diskless2 rc.firewall rc.firewall6 \
> rc.isdn rc.network rc.network6 rc.pccard rc.serial rc.shutdown \
> - rc.syscons rc.sysctl remote rpc security services shells syslog.conf \
> - usbd.conf \
> + rc.syscons rc.sysctl remote rpc security services shells sysctl.conf \
> + syslog.conf usbd.conf \
> etc.${MACHINE_ARCH}/disktab \
> etc.${MACHINE_ARCH}/rc.${MACHINE_ARCH} \
> etc.${MACHINE_ARCH}/ttys \
> Index: sysctl.conf
> ===================================================================
> RCS file: /home/ncvs/src/etc/sysctl.conf,v
> retrieving revision 1.1
> diff -d -u -r1.1 sysctl.conf
> --- sysctl.conf 2000/07/27 22:53:42 1.1
> +++ sysctl.conf 2001/04/19 12:44:09
> @@ -3,3 +3,6 @@
> # This file is read when going to multi-user and its contents piped thru
> # ``sysctl -w'' to adjust kernel values. ``man 5 sysctl.conf'' for details.
> #
> +
> +vfs.vmiodirenable=0 # Set to 1 to enable a new directory allocation policy
> + # (codenamed "dirpref")
--
-Alfred Perlstein - [alfred@freebsd.org]
http://www.egr.unlv.edu/~slumos/on-netbsd.html
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