[vdr] Thread priority of cutting thread in vdr

Darren Salt linux at youmustbejoking.demon.co.uk
Wed Oct 12 18:16:59 CEST 2005


I demand that jori.hamalainen at teliasonera.com may or may not have written...

[snip]
> Cutting also trashes caching, I didn't check how VDR does cutting, but
> earlier (1-2 years ago) I think there was a thread on this list of using
> special disk IO methods for reading disk without caching (data left
> behind). Read ahead caching is ok.

That'd probably be posix_fadvise() (<fcntl.h>; __USE_XOPEN2K must be
defined).

Usage is
  posix_fadvise (fd, offset, length, advise)
where advise is one of FADV_NORMAL, FADV_RANDOM, FADV_SEQUENTIAL,
FADV_WILLNEED, FADV_DONTNEED, FADV_NOREUSE.

> And finally I think the "cut in place" -patch would remove the need of
> cutting queues because cutting is more like file renaming than hard
> copying. [...]

Not renaming. Hard linking, at least where a file would be copied without
cuts and is stored on a filesystem which supports hard links. (Symlinks
aren't useful here.)

-- 
| Darren Salt | d youmustbejoking,demon,co,uk | nr. Ashington,
| Debian,     | s zap,tartarus,org            | Northumberland
| RISC OS     | @                             | Toon Army
|   <URL:http://www.youmustbejoking.demon.co.uk/progs.packages.html>

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