Hi Klaus,

thanks a lot!

Regards,
Alexander

14.04.2015 22:33, Klaus Espenlaub пишет:
Hi Alexander,

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.

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.

Klaus

On 08.04.2015 14:32, [email protected] wrote:
Hello,

I just want to remind about this patch...

Regards,
Alexander

25.02.2015 16:16, [email protected] пишет:
Hello!

We would like to contribute to VirtualBox under MIT license. We want to suggest our changes for multiple VMs starting speed-up.

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 /FindHostNetworkInterfaceByName/ 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.

There are two /VBoxSVC/ logs in attach: before applying our changes and after it. In every case we started 80 VMs at the same time. Statistic of /FindHostNetworkInterfaceByName/ execution time before changes is:

Min: 0.38 s (nspr-31)
Med: 14.13 s (nspr-82)
Max: 37.70 s (nspr-188)
Avg: 15.07 s

Statistic after changes is:

Min: 1.12 s (nspr-85)
Med: 6.56 s (nspr-228)
Max: 17.27 s (nspr-7)
Avg: 5.82 s

Regards,
Alexander


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