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Re: Performance optimization in av::fixup - use buffered IO, not mapped file
- From: Corinna Vinschen <corinna-cygwin at cygwin dot com>
- To: cygwin-developers at cygwin dot com
- Date: Wed, 9 Jan 2013 15:28:30 +0100
- Subject: Re: Performance optimization in av::fixup - use buffered IO, not mapped file
- References: <50C68539.5060005@dancol.org> <50C68E17.9000306@cs.utoronto.ca> <50C68F4E.7070301@dancol.org> <50C69B2C.6000602@cs.utoronto.ca> <50C6ADD3.6070005@dancol.org> <50C7D890.2050704@dancol.org> <50C7F640.5000906@dancol.org> <20121212093207.GA15498@calimero.vinschen.de> <50C8F104.7010804@dancol.org> <20121213082942.GO19874@calimero.vinschen.de>
- Reply-to: cygwin-developers at cygwin dot com
Hi Daniel,
On Dec 13 09:29, Corinna Vinschen wrote:
> On Dec 12 13:03, Daniel Colascione wrote:
> > On 12/12/2012 1:32 AM, Corinna Vinschen wrote:
> > > 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
> >
> > On second thought, this patch probably isn't the best idea. Windows might fix
> > this behavior. Maybe it's better to add a per-OS-version flag.
> >
> > > , 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?
> >
> > I did send it. Can you check with management? If it never arrived, I can send
> > another copy easily enough.
>
> I'll check.
my manager searched and asked everywhere he could think of, but he
didn't find your CA. Sorry for the hassle, but would you mind to send
it again?
Thanks,
Corinna
--
Corinna Vinschen Please, send mails regarding Cygwin to
Cygwin Project Co-Leader cygwin AT cygwin DOT com
Red Hat