Date: Fri, 08 Oct 2004 03:09:35 +0200 From: Pawel Worach <pawel.worach@telia.com> To: Daniel Eischen <deischen@freebsd.org> Cc: freebsd-threads@freebsd.org Subject: Re: BIND9 and libpthread performance Message-ID: <4165E8CF.8090409@telia.com> In-Reply-To: <Pine.GSO.4.43.0410071946320.3130-100000@sea.ntplx.net> References: <Pine.GSO.4.43.0410071946320.3130-100000@sea.ntplx.net>
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Daniel Eischen wrote:
> So that's a true dual CPU system with HTT CPUs (the kernel sees
> 4 CPUs)? Turn HTT off, set kern.threads.virtual_cpu = 1, and try
> using process scope threads. Then set kern.threads.virtual_cpu = 2
> and try again using process scope threads. Then try the same 2
> tests with system scope threads.
Yes, system has two physical cpus with HTT enabled, FreeBSD sees four.
kern.smp.cpus: 4
hw.ncpu: 4
As I don't have access to the datacenter to turn off HTT in the BIOS now
I set machdep.hlt_logical_cpus in loader.conf which should theoretically
do the same thing right?
>
> You can set LIBPTHREAD_SYSTEM_SCOPE in your environment to force
> system scope threads, and set LIBPTHREAD_PROCESS_SCOPE to force
> process scope threads (you needn't rebuild libpthread or your
> application). If they are both set, system scope wins out.
>
The first tests I did where with LIBPTHREAD_SYSTEM_SCOPE set.
Here are new results for all the parameters above.
* kern.threads.virtual_cpu=1, named -n 1 (named still sees four cpus and fires
up four theads if I don't force it not to)
x process-scope-1-cpu
+ system-scope-1-cpu
+--------------------------------------------------------------------------+
|x xx x x + + + + +|
| |_______AM______| |_____M__A_________| |
+--------------------------------------------------------------------------+
N Min Max Median Avg Stddev
x 5 9531.2955 10089.776 9895.4739 9876.4389 211.59661
+ 5 10925.816 11449.187 11082.488 11168.616 244.15478
Difference at 95.0% confidence
1292.18 +/- 333.191
13.0834% +/- 3.37359%
(Student's t, pooled s = 228.456)
* kern.threads.virtual_cpu=2, named -n 2
x process-scope-2-cpu
+ system-scope-2-cpu
+--------------------------------------------------------------------------+
|x x x xx ++ +++|
| |__AM__| |_AM_||
+--------------------------------------------------------------------------+
N Min Max Median Avg Stddev
x 5 8319.6891 8558.6617 8476.9996 8463.3126 96.296725
+ 5 10159.815 10336.033 10284.944 10260.51 74.904761
Difference at 95.0% confidence
1797.2 +/- 125.815
21.2352% +/- 1.48659%
(Student's t, pooled s = 86.2664)
The two thread test results don't look quite right, I will turn off HTT in the
BIOS and redo this in about 12 hours. HTT seems to suck, not using the logical
cpus gives me about ~11k queries per second which is about 1k better than
libc_r, woho!
Thanks! Keep up the good threading work!
--
Pawel
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