On 04/13/2011 02:50 PM, Joerg Roedel wrote: > On Wed, Apr 13, 2011 at 01:48:48PM -0700, Yinghai Lu wrote: >> - addr = memblock_find_in_range(0, 1ULL<<32, aper_size, 512ULL<<20); >> + addr = memblock_find_in_range(0, 1ULL<<32, aper_size, 512ULL<<21); > > Btw, while looking at this code I wondered why the 512M goal is enforced > by the alignment. Start could be set to 512M instead and the alignment > can be aper_size as it should. Any reason for such a big alignment? > > Joerg > > P.S.: The box is still in the office, I will try this debug-patch > tomorrow. The only reason that I can think of is that the aperture itself can be huge, and perhaps 512 MiB is the biggest such known. 512ULL<<21 is of course a particularly moronic way to write 1 GiB, but it was a debug patch. The value 512 MiB apparently comes from 7677b2ef6c0c4fddc84f6473f3863f40eb71821b, which is apparently totally ad hoc; effectively it tries to prevent a collision with kexec by hardcoding the kdump allocation as it sat at that point in time in the GART assignment rules. Yeah. Brilliant. -hpa _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
