[Development] Use static qt libraries

[peng-peter.lan at nokia.com]

I would like to explain the background of this approach.

We are now porting Qt5 (selected modules) on a low profile device (ARM11 at 300MHz). All shared objects can XIP - so there is no need to load libs from ROM to RAM. But a major problem is the loading time of an application (qtbase examples) - it cost ~10-20 seconds to resolve the dependencies among the qt libraries. We believe if we can make a merged shared object, the performance would be greatly improved. By the way, the OS is a proprietary one...

Thanks,
Lan Peng

-----Original Message-----
From: development-bounces+peng-peter.lan=nokia.com at qt-project.org [mailto:development-bounces+peng-peter.lan=nokia.com at qt-project.org] On Behalf Of Storm-Olsen Marius (Nokia-MP/Austin)
Sent: Tuesday, July 24, 2012 9:11 AM
To: Liu Song.7 (Nokia-MP/Beijing); development at qt-project.org; thiago.macieira at intel.com
Subject: Re: [Development] 回复： Re: Use static qt libraries

I have my doubts about how much you'll really gain from that.

This would only give you a large benefit if most applications requires all the libs you bundle together, and that you significantly reduce the total amount of symbols exported by the final shared library. I guess worth a quick try, but I wouldn't spend too much time on it. Most OSes will have pretty good caching of these libs anyways, and time is probably better spent optimizing the initialization of the applications rather than focusing on the time it takes to resolve library symbols.
 
M2c.

-- 
.marius


> -----Original Message-----
> From: development-bounces+marius.storm-olsen=nokia.com at qt-
> project.org [mailto:development-bounces+marius.storm-
> olsen=nokia.com at qt-project.org] On Behalf Of Liu Song.7 (Nokia-
> MP/Beijing)
> Sent: Monday, July 23, 2012 6:06 PM
> To: development at qt-project.org; thiago.macieira at intel.com
> Subject: [Development] 回复： Re: Use static qt libraries
> 
> To reduce the loading time.
> -----原信息-----
> 发件人: ext Thiago Macieira
> 发送：  2012/07/24, 02:09
> 收件人: development at qt-project.org
> 主题： Re: [Development] Use static qt libraries
> 
> 
> On segunda-feira, 23 de julho de 2012 14.39.16, song.7.liu at nokia.com wrote:
> > OK, based on my current understanding, do you mean that:
> > I still need to build all of the current qt modules as static objects, which
> > can be done by OPTS += -static or by other way ?
> 
> No.
> 
> What you need to do is figure out what you want to do in the first place.
> What
> is your objective? What are you trying to accomplish? And why is the current
> solution not enough?
> 
> Don't tell us how you planned on implementing it. Forget libqt5.so.
> --
> Thiago Macieira - thiago.macieira (AT) intel.com
>   Software Architect - Intel Open Source Technology Center
>      Intel Sweden AB - Registration Number: 556189-6027
>      Knarrarnäsgatan 15, 164 40 Kista, Stockholm, Sweden
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