[Qt-interest] Antwort: Re: Antwort: Re: [Qt-embedded-interest] long-term delay for QDir::entryList (), QDir::count() for directory located on USB stick

[Markus Franke]

qt-interest-bounces at trolltech.com schrieb am 01.07.2009 16:05:05:

> (i) Use a usb 2.0 device, bus and driver if you have them available.

The device is USB 2.0 compatible. However, so far we're using an USB 1.1 
OHCI driver.

> (ii) Use a larger block size with VFAT. Is there any reason you really 
must 
> use a 4k block size?

The USB sticks which we purchase are preformatted with 4 KByte cluster 
size. Maybe we should switch over to a different vendor.

> (iii) Use a different file system. There are many alternatives to choose 
from 
> but it depends upon your project requirements.

The USB stick's should be readable within a windows environment. VFAT is 
the most suitable filesystem for this, isn't it?

> (iv) Patch QDir::entryList() and QDir::count() so that they work as fast 
as ls 

Hmmm....sounds not so easy. ;-)

> (if you are sure that ls is nto using cached results).

I am sure.

> (v) Improve the kernel's VFAT driver to work better with small block 
sizes 
> over usb 1.1.

Isn't better than the last option. ;-)

Anyway. Thanks for your help and patience.

Mit freundlichen Grüßen / Best regards

Markus Franke
Entwicklung/ Development

SebaKMT
Hagenuk KMT Kabelmesstechnik GmbH
Röderaue 41
01471 Radeburg / Germany
Reg.Gericht (01067 Dresden) HRB 12567
Geschäftsf.: Dr. Max Iann

Phone +49 (0)35208 84 29142
Fax      +49 (0)35208 84 29249

e-mail: franke.m at sebaKMT.com
web: http//www.sebaKMT.com
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