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Hello!<br>
<br>
We would like to contribute to VirtualBox under MIT license. We want
to suggest our changes for multiple VMs starting speed-up.<br>
<br>
The basic idea is to take out getting of host interfaces from write
lock on host object. When many VMs are starting at the same time
then <i>FindHostNetworkInterfaceByName</i> is called for every
machine and it updates network interfaces. So if umount of VMs is
large enough then execution time of this function greatly increases
due to lock wait.<br>
<br>
There are two <i>VBoxSVC</i> logs in attach: before applying our
changes and after it. In every case we started 80 VMs at the same
time. Statistic of <i>FindHostNetworkInterfaceByName</i> execution
time before changes is:<br>
<br>
<font face="monospace">Min: 0.38 s (nspr-31)<br>
Med: 14.13 s (nspr-82)<br>
Max: 37.70 s (nspr-188)<br>
Avg: 15.07 s</font><br>
<br>
Statistic after changes is:<br>
<font face="monospace"><br>
Min: 1.12 s (nspr-85)<br>
Med: 6.56 s (nspr-228)<br>
Max: 17.27 s (nspr-7)<br>
Avg: 5.82 s</font><br>
<br>
Regards,<br>
Alexander<br>
<br>
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