Issues with video cards w/ large amounts of ram.

Matthew Dillon dillon at
Tue Jan 5 14:33:35 PST 2010

    The KVM for 32 bit kernels is getting a bit squeezed.  The recent pmap
    work ate another 64M from the 1G kernel map and that combined with 
    a graphics card with a 256M frame buffer is enough to run the kernel_map
    out of space after a while.

    This mainly occurs if you have 3G or more of ram in the machine as
    the kernel reserves more KVM for the buffer cache and vnodes when
    you have more ram in the machine.

    The easiest solution if this is happening to you is to reduce the
    graphics memory to 128M or 64M.  Alternatively you can reduce the
    size of the buffer cache slightly.  e.g. if sysctl vfs.nbuf is
    12800 you can reduce it in /boot/loader.conf with something like
    kern.nbuf=9600 (note the sysctl is vfs.nbuf but the loader.conf
    variable is kern.nbuf).

    I am considering my options on how to fix this permanently.

					Matthew Dillon 
					<dillon at>

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