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Date: Thu, 3 Aug 2006 19:08:05 +0200
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
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Subject: Re: cygwin copy problems usb 2.0
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On Aug  3 01:54, Eric Blake wrote:
> > >I'm really seeing the non-optimized cygwin cp behaviour causing bad 
> > >reputation, which could be easily patched and maybe even accepted 
> > >upstream. Who knows. Eric what do think? Would it be worthful to think 
> > >about?
> 
> I don't really want to maintain a Windows API patch, and doubt that

Good.

> it would be accepted upstream.  Now if there were something more
> POSIX-y that we could do to speed things up, such as posix_fadvise,

posix_fadvise can't be implemented nicely, AFAICS.  The POSIX semantics
require an already opened file and the advice is given for an offset and
a length.  The Windows semantics only allow to give the advice for the
whole file, and only switching between FILE_SEQUENTIAL_ONLY or "normal",
using ZwSetInformationFile.  By re-opening the file using ZwOpenFile it
would also be possible to toggle the FILE_RANDOM_ACCESS flag.  Still,
it's always for the whole file, not for an area giving offset and length.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat

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