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Date:	Wed, 12 Jan 2011 14:03:05 +0100
From:	Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To:	cygwin AT cygwin DOT com
Subject:	Re: Adding madvise function in cygwin with a #define
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On Jan 12 13:03, jdzstz - gmail dot com wrote:
> Maybe an implementation option could be:
> 
> 1) Standard advices  that only has a influence in application
> performance, can be executed as current posix_madvise, checking only
> the parameters and doing nothing => MADV_NORMAL, MADV_SEQUENTIAL,
> MADV_RANDOM, MADV_REMOVE, MADV_WILLNEED, MADV_DONTNEED
> 
> 2) Rest of advices, that can modify the behaviour of application and
> generate errors or security problems, so madvise returns always
> "EINVAL"  (as you said in your mail) : MADV_REMOVE, MADV_DONTFORK,
> MADV_DOFORK, MADV_HWPOISON, MADV_SOFT_OFFLINE, MADV_MERGEABLE,
> MADV_UNMERGEABLE
> 
> To reduce problems with applications that uses advises of list number
> 2, this constants would be undefined, so if the aplication code make
> for example an "madvise(p, sz, MADV_DONTFORK)" at least, the problem
> will be detected at compilation time.

Well, ok.  Since that makes madvise basically identical to posix_madvise,
I just exported posix_madvise as madvise as well.  The constants are
defined in sys/mman.h as you proposed.


Corinna

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

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