Date: Wed, 29 Mar 2006 06:42:42 +0000 From: Norbert Koch <nkoch@demig.de> To: Daniel Rudy <dr2867@pacbell.net> Cc: freebsd-hackers@freebsd.org Subject: Re: What is the proper use of mlock(2)/munlock(2)? Message-ID: <442A2C62.4030003@demig.de> In-Reply-To: <442A2918.9050804@pacbell.net> References: <442A2918.9050804@pacbell.net>
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Daniel Rudy schrieb: > Hello FreeBSD Hackers, > > I've been reading the man page on mlock(2) and a number of questions > have arisen about it's use. I have looked at malloc and mmap, and I > have not been able to figure this one out. There doesn't seem to be any > compiler or library options dealing with this either. > > 1) How do you make sure that an allocated address range has been aligned > on a multiple of the page size given FreeBSD's virtual address map? Memory allocated by calling mmap(2) is always page aligned. And its size is always rounded up to a multiple of getpagesize(3). From mmap(2): The mmap() function causes the **pages** starting at addr and continuing for at most len bytes to be mapped from the object described by fd, starting at byte offset offset. If len is not a multiple of the pagesize, the mapped region **may extend past** the specified range. Any such extension beyond the end of the mapped object will be zero-filled. Norbert
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