From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christopher Faylor To: gdb-patches@sources.redhat.com Subject: Re: PATCH: fail to improve psymtab memory consumption Date: Tue, 24 Jul 2001 10:57:00 -0000 Message-id: <20010724135745.E781@redhat.com> References: <20010720212013.7DA695E9D8@zwingli.cygnus.com> <87lmljdz4g.fsf@cgsoftware.com> <87d76uerh8.fsf@cgsoftware.com> <3B5CD3B6.9060106@cygnus.com> <87zo9uaow2.fsf@cgsoftware.com> <1010724161525.ZM20208@ocotillo.lan> <20010724123527.A12918@redhat.com> X-SW-Source: 2001-07/msg00601.html 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