Performance optimization in av::fixup - use buffered IO, not mapped file

Corinna Vinschen corinna-cygwin@cygwin.com
Wed Dec 12 09:32:00 GMT 2012


On Dec 11 19:13, Daniel Colascione wrote:
> On 12/11/2012 5:06 PM, Daniel Colascione wrote:
> > On 12/10/2012 7:51 PM, Daniel Colascione wrote:
> >> The key to generating a binary that repros the problem is to unexec emacs, then
> >> try to repro with that generated binary, not a copy of it.
> > 
> > The real explanation is a lot simpler: the binary is sparse. When you create a
> > file mapping object for a sparse file, Windows discards all cached pages for
> > that file. It makes sense that compilers (and Emacs unexec) would create sparse
> > files as they seek around inside their outputs.
> 
> Anyway, the binary is sparse because our linker produces sparse files.
> 
> Would the Cygwin developers accept this patch?

It's ok with me to remove this code, but there's a small problem.  On
2012-08-17, you wrote off-list, that you're going to send the signed
copyright assignment form.  I never got the ok from my manager.  Did you
miss to send the CA, or did my manager miss to inform me?


Corinna

P.S: A patch also needs a ChangeLog entry...

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



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