From: Eric Anholt Date: Fri, 23 Jan 2009 22:14:21 +0000 (-0800) Subject: x86: work around PAGE_KERNEL_WC not getting WC in iomap_atomic_prot_pfn. X-Git-Tag: v2.6.29-rc3~42^2~3 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ef5fa0ab24b87646c7bc98645acbb4b51fc2acd4;p=pandora-kernel.git x86: work around PAGE_KERNEL_WC not getting WC in iomap_atomic_prot_pfn. In the absence of PAT, PAGE_KERNEL_WC ends up mapping to a memory type that gets UC behavior even in the presence of a WC MTRR covering the area in question. By swapping to PAGE_KERNEL_UC_MINUS, we can get the actual behavior the caller wanted (WC if you can manage it, UC otherwise). This recovers the 40% performance improvement of using WC in the DRM to upload vertex data. Signed-off-by: Eric Anholt Signed-off-by: H. Peter Anvin --- Reading git-diff-tree failed