[vbox-dev] very slow installing windows 7 sp1 beta refresh

[walt]

On 09/13/2010 05:49 AM, Frank Mehnert wrote:
> On Sunday 12 September 2010, walt wrote:

>> I'm using the latest OSE.svn, and I'm seeing Windows 7 guests running at
>> one-third the usual speed (linux host).

> We also had a check of the time which is used for a Windows 7 installation
> and were not able to observe any differences between 3.2.8 and current trunk.
> We tested this on an Intel Xeon E5345 (2 x 4 cores) on Windows Server 2008.

I found the guilty commit:

------------------------------------------------------------------------
r32410 | vboxsync | 2010-09-10 07:19:33 -0700 (Fri, 10 Sep 2010) | 2 lines

Got rid of unnecessary dirty page flush in InvalidatePage. (NOTE: high risk change)
------------------------------------------------------------------------

I guess this must be a different problem than the one Huihong Luo reported
because this is a very recent commit.

The difference is actually more like four times slower: 64-bit Windows7 on
64-bit linux host normally takes 27 seconds from power-on to login prompt,
but after this commit it takes 74 seconds.  Not negligible.

I don't have any Windows hosts I can test -- I don't need a Windows machine
any longer thanks to you guys :)