Re: [PATCH 3/3] grep: remove --mmap

[Jim Meyering]

Paolo Bonzini wrote:

> mmap is a bad idea for sequentially accessed file because it will cause
> a page fault for every read page.  Just consider it a failed experiment,
> and ignore --mmap while accepting it for backwards compatibility.
>
> * configure.ac (AC_FUNC_MMAP): Remove.
> * doc/grep.texi (Other options): Remove --mmap.
> * src/grep.c (mmap_option): Remove.
> (long_options): Do not reference it.
> (bufmapped, initial_bufoffset): Remove.
> (reset, fillbuf): Remove HAVE_MMAP code.
> (grepfile): Remove bufmapped reference.
> (usage): Remove --mmap.
...
> -      --help                display this help and exit\n\
> -      --mmap                use memory-mapped input if possible\n"));
> +      --help                display this help and exit\n"));

This is fine, but as long as --mmap is still accepted, it's best to
leave traces of it in --help and texinfo docs, so that people
understand why --max-count=N may not (yet) be abbreviated as --m=N.

Also, please add a comment saying something like this:

  FIXME: undocumented in Mar 2010; warn in N; remove in M

so it doesn't stay with us forever.
Making N=2011 or 2012 works for me, and M=N+2 seems like enough lead time.