Performance optimization in av::fixup - use buffered IO, not mapped file
Corinna Vinschen
corinna-cygwin@cygwin.com
Thu Dec 13 19:21:00 GMT 2012
On Dec 13 11:02, Daniel Colascione wrote:
> On 12/13/12 2:39 AM, Corinna Vinschen wrote:
> > On Dec 13 01:44, Daniel Colascione wrote:
> >> What about using the automatic sparse handling in lseek/lwrite and
> >> ftruncate only when the file being operated on is already sparse?
> >
> > That doesn't make sense. If the file is already sparse, there's no
> > reason to set the sparse flag in write or ftruncate again. Also, if you
> > set the sparse flag only on already sparse files, you will never be able
> > to create sparse
>
> Yes, you're right. I thought I remembered a separate call we could
> have retained to actually punch a hole in a sparse file.
That's what Eric mentioned yesterday. The Linux-specific fallocate call
can do that, but this isn't implemented in Cygwin yet(*).
Corinna
(*) http://cygwin.com/ml/cygwin-developers/2012-12/msg00018.html
--
Corinna Vinschen Please, send mails regarding Cygwin to
Cygwin Project Co-Leader cygwin AT cygwin DOT com
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