Reduces the locking and fencing overhead.

v2: add comment why we need the duplicates list in the GEM op.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NJammy Zhou <Jammy.Zhou@amd.com>