Date: Tue, 26 Aug 1997 13:22:50 +0930 From: Mike Smith <mike@smith.net.au> To: Greg Lehey <grog@lemis.com> Cc: Joerg Wunsch <joerg_wunsch@uriah.heep.sax.de>, "hackers@freebsd.org" <hackers@FreeBSD.ORG>, Mike Burgett <mburgett@awen.com> Subject: Re: special malloc needs... Message-ID: <199708260352.NAA00731@word.smith.net.au> In-Reply-To: Your message of "Tue, 26 Aug 1997 12:42:23 %2B0930." <19970826124223.62337@lemis.com>
next in thread | previous in thread | raw e-mail | index | archive | help
> On Mon, Aug 25, 1997 at 10:20:08PM +0200, J Wunsch wrote: > > As Mike Burgett wrote: > > > >> Is there any way to malloc memory (from userland code) that is at > >> specific offsets from each other in physical memory (i.e. 2 chunks > >> exactly XXM apart in physical RAM) or failing that, to allocate a > >> very large (>32M) chunk of contig physical RAM? (again, from > >> userland?) > > > > No, you can't do this. You get virtual memory, nothing else. It's > > not even backed with physical memory at all when you've got it. > > Well, you can't malloc() it, but you can try to mmap() it with > MAP_FIXED. man mmap(2). This only gives you a fixed _virtual_ address. > > What the h*ck would you need this in a userland program? > > Good question. It sounds like a bad practice to me. It's almost guaranteed that either there is a hidden agenda (and I hate it when people don't explain their stupid questions), or the individual in question doesn't understand what they're asking. So Mike, what is it? mike
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199708260352.NAA00731>