drm/vmwgfx: Fix a buffer object eviction regression v2

Commit Message

Thomas Hellstrom Sept. 24, 2018, 11:50 a.m. UTC

Commit 4eb085e42fde ("drm/vmwgfx: Convert to new IDA API") introduced
an incorrect return value from the function vmw_gmrid_man_get_node(),
when we run out of integer ids. Instead of returning 0 (meaning
non-fatal error) we forward the ida_simple_get error code -ENOSPC.
This causes TTM not to retry allocation after buffer eviction and
instead return -ENOSPC to user-space.

Fix this by returning 0 when ida_simple_get() returns other error codes
than -ENOMEM:

Tested using glretrace.

Cc: <[e-mail]>
Signed-off-by: Thomas Hellstrom <[e-mail]>
Reviewed-by: Sinclair Yeh <[e-mail]>
---
v2: Test for -ENOMEM instead of -ENOSPC
---
 drivers/gpu/drm/vmwgfx/vmwgfx_gmrid_manager.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Matthew Wilcox Sept. 24, 2018, 1:24 p.m. UTC | #1

On Mon, Sep 24, 2018 at 11:50:02AM +0000, Thomas Hellstrom wrote:
> Commit 4eb085e42fde ("drm/vmwgfx: Convert to new IDA API") introduced
> an incorrect return value from the function vmw_gmrid_man_get_node(),
> when we run out of integer ids. Instead of returning 0 (meaning
> non-fatal error) we forward the ida_simple_get error code -ENOSPC.
> This causes TTM not to retry allocation after buffer eviction and
> instead return -ENOSPC to user-space.
> 
> Fix this by returning 0 when ida_simple_get() returns other error codes
> than -ENOMEM:
> 
> Tested using glretrace.
> 
> Cc: <[e-mail]>
> Signed-off-by: Thomas Hellstrom <[e-mail]>
> Reviewed-by: Sinclair Yeh <[e-mail]>

Reviewed-by: Matthew Wilcox <[e-mail]>

Patch

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_gmrid_manager.c b/drivers/gpu/drm/vmwgfx/vmwgfx_gmrid_manager.c
index b93c558dd86e..c1cdf6975396 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_gmrid_manager.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_gmrid_manager.c
@@ -57,7 +57,7 @@  static int vmw_gmrid_man_get_node(struct ttm_mem_type_manager *man,
 
 	id = ida_alloc_max(&gman->gmr_ida, gman->max_gmr_ids - 1, GFP_KERNEL);
 	if (id < 0)
-		return id;
+		return (id == -ENOMEM ? -ENOMEM : 0);
 
 	spin_lock(&gman->lock);