From: Thomas Hellstrom <thellstrom@xxxxxxxxxx> For shared, and read-only private mappings of graphics memory, use VM_PFNMAP instead of VM_MIXEDMAP. This means less accounting overhead when inserting and removing page-table entries. TTM doesn't do this by default, since there was a performance problem with book-keeping of write-combined mappings. Since vmwgfx solely uses cached mappings, that's not a problem and now that the TTM vm has largely been turned into helpers, we can use VM_PFNMAP on a per-driver basis Signed-off-by: Thomas Hellstrom <thellstrom@xxxxxxxxxx> Reviewed-by: Roland Scheidegger <sroland@xxxxxxxxxx> --- drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c index ce288756531b..aa7e50f63b94 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c @@ -45,6 +45,10 @@ int vmw_mmap(struct file *filp, struct vm_area_struct *vma) vma->vm_ops = &vmw_vm_ops; + /* Use VM_PFNMAP rather than VM_MIXEDMAP if not a COW mapping */ + if ((vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) != VM_MAYWRITE) + vma->vm_flags = (vma->vm_flags & ~VM_MIXEDMAP) | VM_PFNMAP; + return 0; } -- 2.21.0 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
