Re: ufs multilabel performance (fwd)

Am 04/15/12 22:00, schrieb Garrett Cooper:
On Apr 15, 2012, at 12:30 PM, O. Hartmann wrote:

Am 04/15/12 15:59, schrieb Richard Kojedzinszky:
Thank you for the reply.

Unfortunately, dont know why, but on my xen virtualised environment,
fbsd amd64 domU performs much slower, not only 30 times. Without
multilabel, file creation speed is around 2500/s, but with multilabels
enabled, it is only 15/s (!). so it is more than 100 times slower.

And anyway freebsd is known to be fast as well, as functional. The power
to serve. :)

But in my environment, 15/s file creation is very-very slow. The
hardware is a q6700 cpu with 4G ram, 2x1T sata disks in raid1, the host
runs linux. I think with this hw the mentioned speed is really slow.


Kojedzinszky Richard
Euronet Magyarorszag Informatikai Zrt.

On Sun, 15 Apr 2012, O. Hartmann wrote:

Date: Sun, 15 Apr 2012 13:20:23 +0200
From: O. Hartmann <ohartman@xxxxxxxxxxxxxxxxxx>
To: Richard Kojedzinszky <krichy@xxxxxxxxxxxx>
Cc: freebsd-security@xxxxxxxxxxx
Subject: Re: ufs multilabel performance (fwd)

Am 04/14/12 21:37, schrieb Richard Kojedzinszky:
Dear list,

Although it is not only security-related question, I did not get any
answer from freebsd-performance. The original question is below.

Can someone give some advice?

Thanks in advance,

Kojedzinszky Richard
Euronet Magyarorszag Informatikai Zrt.

---------- Forwarded message ----------
Date: Thu, 10 Nov 2011 06:16:57 +0100 (CET)
From: Richard Kojedzinszky <krichy@xxxxxxxxxxxx>
To: freebsd-performance@xxxxxxxxxxx
Subject: ufs multilabel performance

Dear List,

I've noticed that when I enable multilabel on an fs, a file creation
gets around 20-30 times slower than without multilabel set.

This one-liner can be used to test the differences:
$ truss -D perl -e 'open(F, ">$_.file") for 1 .. 1000'

Same here, creating files seems to be 10 - 30 times slower with
multilabels as it is without.

But as several posts and discussions reflects, FreeBSD isn't supposed to
be fast although it is claimed that writing is the major than reading;
FBSD should serve functionality.

And one can see that the open call takes much more when multilabel is
set on an fs. It seems that only file creation needs that many time,
when a file exists it is opened much faster.

Could someone acknowledge this, and have some suggestions how to make it


Kojedzinszky Richard
TvNetWork Nyrt.
E-mail: krichy (at) tvnetwork [dot] hu
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At the moment, I'm troubled with a nasty kernel bug on all FreeBSD 10
boxes I have spare to test.

I just tried to reproduce your observation and as far as I can go with
my experience, I can confirm that by using your perl script.

I'd like to test this again with a small C program.

I can only test the issue (test is too far optimistic, it's simply a
reproduction of your observation) on FreeBSD 10, the only remaining
FreeBSD server at our department is running FBSD 9-STABLE/amd64 and "in
production", so changing multilabel support is a bit harsh at the moment.

Sorry about crossposting, but I think this belongs more to CURRENT and

My suggestion is completely take perl out of the equation because the way you're invoking it above uses stdio and a few other things that add unnecessary overhead.

Try the attached C program/bourne shell snippet instead.



set -e

tmp=$(mktemp -d tmp.XXXXXX)
trap "cd /; rm -Rf $tmp" EXIT
cd $tmp

cat > test_open.c <<EOF

#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>

char buf[20];
int i;

for (i = 0; i < 1000; i++) {
sprintf(buf, "%d", i);
close(open(buf, O_WRONLY|O_CREAT, 0600));
return (0);

gcc -o test_open test_open.c
time ./test_open_______________________________________________

This was pretty fast ;-)

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