Date: Wed, 23 Apr 1997 20:10:06 +0100 (BST) From: Stephen Roome <steve@visint.co.uk> To: Steve Passe <smp@csn.net> Cc: freebsd-smp@freebsd.org Subject: Re: hardware list Message-ID: <Pine.BSF.3.91.970423191200.12466D-100000@bagpuss.visint.co.uk> In-Reply-To: <199704231651.KAA22820@Ilsa.StevesCafe.com>
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On Wed, 23 Apr 1997, Steve Passe wrote:
> Hi,
> > What sort of kernel compile times should be expected, with my last compile
> >
> > make -j8 it took 3 minutes and 48 seconds for a Generic kernel with
> > the sysv stuff for X, and none of the drivers I'm not using.
> > (i.e. one net card a 2940 and 2 processors, nothing much else but 1 com
> > port for a mouse)
> >
> > and make -j16 took 3 minutes 19 seconds on the same
> > kernel.
> >
> > So, are these good times then ?
>
> they're better than I got from my dual P5-133 with slow SCSI disk:
> make -j8 4min 20sec
>
> for a fairly dramatic speedup add this line to your /etc/make.conf file:
>
> COPTFLAGS= -pipe
(Oh dear, you've got me going on the 'benchmark your computer' thing again)
I have this at the moment
CFLAGS=-O6 -pipe -m486
#COPTFLAGS=-O -pipe
notice this is commented out.
HAVE_FPU=yes
right now, and that's what the last two compiles ran under, I'd be surprised
though if your disk is slower than this Quantum Fireball here. with iozone 51
I get:
IOZONE performance measurements:
2894335 bytes/second for writing the file
4024164 bytes/second for reading the file
That's one Quantum Fireball 3.5 series disk, which isn't much good by my
standards. Besides, I haven't mounted it async,noatime yet, I'm just
testing these speed as a plain drive.. I'll try freaky mount options
later =!
(I'll be adding a 2gb seagate hawk as well soon.)
Anyway, I just chucked COMPAT_LINUX in as well and this is what I get
------
CFLAGS =-06 -pipe -m486
COPTFLAGS commented out of make.conf,
HAVE_FPU=yes
Wed Apr 23 19:12:59 BST 1997 start time
= 55 second make depend
Wed Apr 23 19:13:54 BST 1997 end of make depend
= 3 minutes 36 seconds for make -j8
Wed Apr 23 19:17:30 BST 1997 end of make -j8
-----
This was interesting so I put the COPTFLAGS back in the make.conf and
tried again. This time:
-----
CFLAGS =-O6 -pipe -m486
COPTFLAGS = -O -pipe
HAVE_FPU =yes
Wed Apr 23 19:24:50 BST 1997 start make
= 51 second make depend
Wed Apr 23 19:25:41 BST 1997 end of make depend
= 3 minutes 24 seconds for make -j8
Wed Apr 23 19:29:05 BST 1997 end of make -j8
Not a huge improvement, only -slightly- (worth it?) better.
-----
Now, this (a make -j16) is interesting though:
CFLAGS =-O6 -pipe -m486
COPTFLAGS=-O -pipe
HAVE_FPU=yes
Wed Apr 23 19:34:14 BST 1997 start make
= 1 minute 1 second for a make depend
Wed Apr 23 19:35:05 BST 1997 end of make depend
= 3 minutes 27 second for make -j16
Wed Apr 23 19:38:33 BST 1997
-j16 doesn't seem to make any difference ?
I can't find anything to say make doesn't accept more than 8 jobs max..
So I wondered what -j64 would do !? I assume that for a machine with
512MB of memory -jBIGNUMBER would be good.. Anyway, I'm trying these
things out, if you have some more interesting tests please let me know!
This is from a make -j64, obviously the -j64 happened, and was too much
for this machine on memory (can't easily check this while timing it.)
-----
Wed Apr 23 19:41:43 BST 1997 start make
= 52 seconds for the make depend
Wed Apr 23 19:42:35 BST 1997 end make depend
= 4 minutes 42 seconds for a make -j64
Wed Apr 23 19:47:17 BST 1997
-----
I'm gonna write a script that just does this with as many different
settings and see if I get the improvements I expect. (could do some nice
graphs perhaps.) Then it'll be obivous where too little memory becomes
the major factor and where disk access is slowing it down much.
(Although it won't be tonight as I'm going to leave my other 4 FreeBSD
machines running scripts to get random files (quickly!) through httpd from
this server to see if I can tweak the settings for and number of httpd's to
run!)
Just for fun make -j200 took 53 secs for make depend, 5 min 50 secs for
the make =) (mmm maybe it's not memeory slowing this down?)
Perhaps make should have a -J option saying start as many processes as
possible without getting the swap space usage to increase, and with some
limit on the amount of process swapping that ends up happening.
Steve Roome
(Anyone interested in a unix benchmark site or can point me at one?)
--
Steve Roome
Technical Systems Manager, Vision Interactive Ltd.
E: steve@visint.co.uk M: +44 (0) 976 241 342
T: +44 (0) 117 973 0597 F: +44 (0) 117 923 8522
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