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Hi Alexander,<br>
<br>
5.0.0BETA2 will contain a modification inspired by your patch, which
should actually lower the time during which the lock is held even
further.<br>
<br>
There would be ways to optimize it much further (I left a todo
comment in the code hinting what needs doing and what the
difficulties are), but decided against doing it now.<br>
<br>
Klaus<br>
<br>
<div class="moz-cite-prefix">On 08.04.2015 14:32, <a class="moz-txt-link-abbreviated" href="mailto:a.urakov@drweb.com">a.urakov@drweb.com</a>
wrote:<br>
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<blockquote cite="mid:55251FE4.2020503@drweb.com" type="cite">
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Hello,<br>
<br>
I just want to remind about this patch...<br>
<br>
Regards,<br>
Alexander<br>
<br>
<div class="moz-cite-prefix">25.02.2015 16:16, <a
moz-do-not-send="true" class="moz-txt-link-abbreviated"
href="mailto:a.urakov@drweb.com">a.urakov@drweb.com</a> пишет:<br>
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<blockquote cite="mid:54EDCB27.9020306@drweb.com" type="cite">
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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
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