Commits
Thomas Hellstrom committed 0e6d6ec02f8
drm/ttm: Work around performance regression with VM_PFNMAP A performance regression was introduced in TTM in linux 3.13 when we started using VM_PFNMAP for shared mappings. In theory this should've been faster due to less page book-keeping but it appears like VM_PFNMAP + x86 PAT + write-combine is a particularly cpu-hungry combination, as seen by largely increased cpu-usage on r200 GL video playback. Until we've sorted out why, revert to always use VM_MIXEDMAP. Reference: freedesktop.org bugzilla bug #75719 Reported-and-tested-by: <smoki00790@gmail.com> Acked-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com> Cc: stable@vger.kernel.org