Re: PATCH: fail to improve psymtab memory consumption

[Christopher Faylor <cgf at redhat dot com>]

On Tue, Jul 24, 2001 at 01:13:29PM -0400, Frank Ch. Eigler wrote:
>cgf wrote:
>: [...]  FWIW, Cygwin's mmap is not 100% compliant with UNIX.  [...]
>
>Right, but for the use which dberlin has in mind (vanilla mapping of
>plain file pages into memory), Cygwin's implementation has been quite
>satisfactory in other projects.  Is even this vanilla use of mmap
>controversial among modern UNIX boxes?

I'm just raising the flag.  As soon as we start using mmap, I *know*
that there will be thoughts along the line of "Hmm.  We're already using
mmap.  If I use MAP_PRIVATE here, then it will be a big performance
win!"

Historically, cygwin has been an afterthought in gcc, and to some extent
in gdb.

As far as problems with mmap on UNIX systems go, the only system I can
recall having real problems with is Ultrix.  That's not a modern system,
but it is still listed in configure.host.

>(Yeah, but they do more clever things with mmap to support their
>internal garbage collection scheme.)

I don't think that the gcc use was all that unusual.  It just exercised
underdeveloped parts of cygwin's mmap.

cgf