Date: Wed, 14 Nov 2007 15:31:40 -0500 From: John Baldwin <jhb@freebsd.org> To: freebsd-hackers@freebsd.org Cc: Rob Belics <rob_belics@charter.net> Subject: Re: FreeBSD cache memory allocation Message-ID: <200711141531.40481.jhb@freebsd.org> In-Reply-To: <473B1E3D.30500@charter.net> References: <473B1E3D.30500@charter.net>
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On Wednesday 14 November 2007 11:11:41 am Rob Belics wrote: > Someone I can't stand said this about FreeBSD. Though I know C, I don't > know anything about this and would love to respond. My first thought was > 'contigmalloc' but I'm not sure it's equivalent. > [QUOTE]The kernel is really lacking some features. They need a method to > set precise type of memory cache but BSD doesn't provide way to specify > memory cache. > > For that reason MS has the beautiful > MmAllocateContigousMemorySpecifyCache()[/QUOTE] For kernel memory on i386 and amd64 in 6.3 and later you can use pmap_change_attr() to adjust the caching mode of memory after you have allocated it. It is best used only with allocations that are a multiple of the page size. -- John Baldwin
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