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| author | Thomas Hellstrom <thellstrom@vmware.com> | 2014-03-12 10:41:32 +0100 |
|---|---|---|
| committer | Thomas Hellstrom <thellstrom@vmware.com> | 2014-03-12 14:07:24 +0100 |
| commit | 0e6d6ec02f867fe8d1f785312b7343b21052322f (patch) | |
| tree | de3e45232186d8eac91b34bf4bd2124a371a9749 /Makefile | |
| parent | 45db98e54242f3ae94bdcfbfe754e743252eb168 (diff) | |
| download | op-kernel-dev-0e6d6ec02f867fe8d1f785312b7343b21052322f.zip op-kernel-dev-0e6d6ec02f867fe8d1f785312b7343b21052322f.tar.gz | |
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
Diffstat (limited to 'Makefile')
0 files changed, 0 insertions, 0 deletions
