Date: Thu, 8 Nov 2001 15:09:39 -0500 From: "Jason Mawdsley" <jason@macadamian.com> To: "mark tinguely" <tinguely@web.cs.ndsu.nodak.edu>, <bright@mu.org> Cc: <freebsd-hackers@FreeBSD.ORG> Subject: Re: mmap/madvise Message-ID: <02ae01c16891$4c1f4970$2a64a8c0@macadamian.com> References: <200111081947.fA8JlAe03457@web.cs.ndsu.nodak.edu>
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> Jason Mawdsley <jason@macadamian.com> asks: > > > > I am looking for a way to reserve memory, without actually allocating the > > > swap space. > > Alfred Perlstein answers: > > > Just proceed normally, freebsd does overcommit such that you really > > don't need to do anything special to get the results you desire. > > I assume Jason is writting a userland application, but I cannot tell > how he was using the allocated memory. Alfred is correct in that > allocated memory is not even physical until needed and only paged back > if modified AND space becomes low. > > Without information of what he was doing, I was trying to read between > the lines of his message and wonder if he needs the memory physically > there and wired (using mprotect) to prevent the memory from being released. I am creating a virtual memory manager. Currently I am doing a mmap(...PROT_NONE, MAP_ANON ) to reserve the memory. then when committing the memory I am using mprotect( ...PROT_READ | PROT_WRITE ) HTH Jason Mawdsley ~ jason@macadamian.com m_ a c a d a m i a n t e c h n o l o g i e s "Software developers for the world's leading technology companies." http://www.macadamian.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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