[PATCH 1/3] drm/ttm/dma: Only call set_pages_array_wb when the page is not in WB pool.
From: Konrad Rzeszutek Wilk
Date: Wed Jan 04 2012 - 16:37:28 EST
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@xxxxxxxxxx>
---
drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 7 +++++--
1 files 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 6678abc..6c06d0b 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);
--
1.7.7.4
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