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Re: detecting mmap?
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From: |
Paul Eggert |
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Subject: |
Re: detecting mmap? |
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Date: |
Thu, 18 Jul 2002 23:45:41 -0700 (PDT) |
> From: "Donn Terry" <address@hidden>
> Date: Wed, 17 Jul 2002 10:01:54 -0700
>
> It's perfectly reasonable for the implementation to consider an address
> in the (ordinary) heap as invalid (just as much as it might consider code or
> data invalid).
It may sound perfectly reasonable to _you_, but but it doesn't sound
reasonable to _me_. Such an implementation will break or will hurt
the performance of several applications (GNU grep being one example).
That being said, it wouldn't hurt to have a different flavor of
AC_FUNC_MMAP that has a weaker check for compatibility, for
applications that don't need MMAP_FIXED. We've already done this for
AC_FUNC_FNMATCH versus AC_FUNC_FNMATCH_GNU; the former tests only for
POSIX compatibility whereas the latter also tests for GNU
compatibility.
The argument for such a change would be stronger if (1) we had a
proposed patch, and (2) the existing AC_FUNC_MMAP was seriously
hurting some applications on some platforms. (Do you have any
examples of this in mind?)