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Date:      Tue, 3 Dec 2019 00:12:43 -0800 (PST)
From:      "Rodney W. Grimes" <freebsd-rwg@gndrsh.dnsmgr.net>
To:        Wojciech Puchar <wojtek@puchar.net>
Cc:        freebsd-hackers@freebsd.org
Subject:   Re: bhyve+windows 7 multicore performance
Message-ID:  <201912030812.xB38ChQ0033844@gndrsh.dnsmgr.net>
In-Reply-To: <alpine.BSF.2.20.1912021129580.20911@puchar.net>

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> i am already using bhyve to run windows 7 guests on one server, all are 
> small guests with 1 or 2 cores allocated. Works fine with good 
> performance.
> 
> Recently i changed computer configuration in one of my client's office.
> 
> Before:
> low end PC as unix server
> Dell T110-II with quad core Xeon E3 v1 running windows 7 natively
> 
> After:
> New server with CPU: Intel(R) Xeon(R) E-2136 CPU @ 3.30GHz
> (6 cores*2 threads)
> as unix server with windows 7 moved to bhyve.
> 
> 
> i run bhyve VM like this:
> nice -n -20 /usr/sbin/bhyve -s 0,hostbridge -m 22528M \
 ^^^^^^^^^^^^  why?

> -H -P -S -c cpus=11,sockets=1,cores=11,threads=1 \
> -s 7,fbuf,rfb=10.2.3.4:5900,password=secret \
> -s 3,ahci,hd:/dev/ada2p5.eli,hd:/dev/ada2p6.eli,hd:/dev/ada2p127.eli \
> -s 5,virtio-net,tap0,mac=08:00:27:b7:ca:16 \
> -s 30,virtio-rnd -s 31,lpc -U 0072c755-0e33-11ea-b92a-4c53821d28a6 \
> -l bootrom,/usr/local/share/uefi-firmware/BHYVE_UEFI.fd -w windows
> 
> And it runs properly with 11 threads available for windows.

I am not so sure about how well the SMP code in windows 7
deals with this odd core count, or for that matter more than 4
cores as at the time Windows 7 was released not many systems
existed above 4 cores.

> 
> But windows feels quite slower that it was before. There is for sure no 
> problem with I/O performance. It's about compute speed.

How did you measure this?  If it is just a "feel" then it could
be almost anything, if you have some solid numbers to look at
then perhaps some conclusions can be made.

> What i do wrong?

Try 4 cores, and drop the priority boost, you may be causeing
an unintended side effect.

Did you copy the windows 7 from the old server, or is this
a new install to the VM.  If you copied it there may be a
HAL issue/missmatch.

-- 
Rod Grimes                                                 rgrimes@freebsd.org



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