Commits
Konrad Rzeszutek Wilk committed 36d7c537c30
drm/ttm/dma: Only call set_pages_array_wb when the page is not in WB pool. Otherwise we are doing redundant work. Especially since the 'unbind' and 'unpopulate' have been merged and nouveau driver ends up calling it quite excessivly. On a GeForce 8600 GT with Gnome Shell (GNOME 3) we end up spending about 54% CPU time in __change_page_attr_set_clr checking the page flags. The callgraph (annotated) looks as so before this patch: 53.29% gnome-shell [kernel.kallsyms] [k] static_protections | --- static_protections | |--91.80%-- __change_page_attr_set_clr | change_page_attr_set_clr | set_pages_array_wb | | | |--96.55%-- ttm_dma_unpopulate | | nouveau_ttm_tt_unpopulate | | ttm_tt_destroy | | ttm_bo_cleanup_memtype_use | | ttm_bo_release | | kref_put | | ttm_bo_unref | | nouveau_gem_object_del | | drm_gem_object_free | | kref_put | | drm_gem_object_unreference_unlocked | | drm_gem_object_handle_unreference_unlocked.part.1 | | drm_gem_handle_delete | | drm_gem_close_ioctl | | drm_ioctl | | do_vfs_ioctl | | sys_ioctl | | system_call_fastpath | | __GI___ioctl | | | --3.45%-- ttm_dma_pages_put | ttm_dma_page_pool_free | ttm_dma_unpopulate | nouveau_ttm_tt_unpopulate | ttm_tt_destroy | ttm_bo_cleanup_memtype_use | ttm_bo_release | kref_put | ttm_bo_unref | nouveau_gem_object_del | drm_gem_object_free | kref_put | drm_gem_object_unreference_unlocked | drm_gem_object_handle_unreference_unlocked.part.1 | drm_gem_handle_delete | drm_gem_close_ioctl | drm_ioctl | do_vfs_ioctl | sys_ioctl | system_call_fastpath | __GI___ioctl | --8.20%-- change_page_attr_set_clr set_pages_array_wb | |--93.76%-- ttm_dma_unpopulate | nouveau_ttm_tt_unpopulate | ttm_tt_destroy | ttm_bo_cleanup_memtype_use | ttm_bo_release | kref_put | ttm_bo_unref | nouveau_gem_object_del | drm_gem_object_free | kref_put | drm_gem_object_unreference_unlocked | drm_gem_object_handle_unreference_unlocked.part.1 | drm_gem_handle_delete | drm_gem_close_ioctl | drm_ioctl | do_vfs_ioctl | sys_ioctl | system_call_fastpath | __GI___ioctl | --6.24%-- ttm_dma_pages_put ttm_dma_page_pool_free ttm_dma_unpopulate nouveau_ttm_tt_unpopulate ttm_tt_destroy ttm_bo_cleanup_memtype_use ttm_bo_release kref_put ttm_bo_unref nouveau_gem_object_del drm_gem_object_free kref_put drm_gem_object_unreference_unlocked drm_gem_object_handle_unreference_unlocked.part.1 drm_gem_handle_delete drm_gem_close_ioctl drm_ioctl do_vfs_ioctl sys_ioctl system_call_fastpath __GI___ioctl and after this patch all of that disappears. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Dave Airlie <airlied@redhat.com>