[Pfspd-users@sf.net] CPFSPD performance bug solved

[Bram R. <bra...@nx...>]

Hi all,

Today, I solved a performance bug in the cpfspd file I/O (fio) module.
The fix is available in the source code repository, no release yet.

>From the readme file:
- Windows file I/O performance bug fixed. In some cases, reading a image
  near the end of the file was very time-consuming (though correct data
  was returned). Detailed explanation: jump to an image in the last buffer
  and start reading there. This caused a ReadFile of the next buffer, which
  happens to be located _after_ the end of the file. This "read ahead"
  operation returned an eof flag, which was (erroneously) ignored. Hence,
  every successive fread() operation caused this ReadFile attempt on the
  file system, resulting in a huge overhead. In cpfspd, every video line
  is read using a fread(). This is solved by taking the eof flag into
  account when starting the "read ahead" ReadFile operation.

Developers, please update. Further, a review of this fix is welcome...

Tot ziens / Kind regards, Bram
--
Bram Riemens
Senior Principal, Central R&D / Research
NXP Semiconductors

High Tech Campus 32 (floor 1, office 138), 5656 AE Eindhoven, The Netherlands
Tel: +31 40 27 25910; Fax: +31 40 27 29648
Email: bra...@nx...

The information contained in this message is confidential and may be legally privileged. The message is intended solely for the addressee(s). If you are not the intended recipient, you are hereby notified that any use, dissemination, or reproduction is strictly prohibited and may be unlawful. If you are not the intended recipient, please contact the sender by return e-mail and destroy all copies of the original message.

Unless otherwise recorded in a written agreement, all sales transactions by NXP Semiconductors are subject to our general terms and conditions of commercial sale. These are published at www.nxp.com/profile/terms/index.html<http://www.nxp.com/profile/terms/index.html>