From 36d7c537c3082a492ff851fb0da40ae3d7c5565d Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Wed, 4 Jan 2012 16:35:14 -0500 Subject: [PATCH] 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 Signed-off-by: Dave Airlie --- drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c index 6678abca0d98..6c06d0b601f9 100644 --- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c +++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c @@ -384,7 +384,9 @@ static void ttm_dma_pages_put(struct dma_pool *pool, struct list_head *d_pages, { struct dma_page *d_page, *tmp; - if (npages && set_pages_array_wb(pages, npages)) + /* Don't set WB on WB page pool. */ + if (npages && !(pool->type & IS_CACHED) && + set_pages_array_wb(pages, npages)) pr_err(TTM_PFX "%s: Failed to set %d pages to wb!\n", pool->dev_name, npages); @@ -396,7 +398,8 @@ static void ttm_dma_pages_put(struct dma_pool *pool, struct list_head *d_pages, static void ttm_dma_page_put(struct dma_pool *pool, struct dma_page *d_page) { - if (set_pages_array_wb(&d_page->p, 1)) + /* Don't set WB on WB page pool. */ + if (!(pool->type & IS_CACHED) && set_pages_array_wb(&d_page->p, 1)) pr_err(TTM_PFX "%s: Failed to set %d pages to wb!\n", pool->dev_name, 1); -- GitLab