[RFC PATCH 3/4] drm/ttm: Handle -EAGAIN in ttm_resource_alloc as -ENOSPC.

From: Maarten Lankhorst
Date: Wed May 03 2023 - 05:00:21 EST


This allows the drm cgroup controller to return no space is available..

XXX: This is a hopeless simplification that changes behavior, and
returns -ENOSPC even if we could evict ourselves from the current
cgroup.

Ideally, the eviction code becomes cgroup aware, and will force eviction
from the current cgroup or its parents.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/ttm/ttm_bo.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index bd5dae4d1624..e057d5d8f09a 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -731,6 +731,8 @@ static int ttm_bo_mem_force_space(struct ttm_buffer_object *bo,
ret = ttm_resource_alloc(bo, place, mem);
if (likely(!ret))
break;
+ if (ret == -EAGAIN)
+ return -ENOSPC;
if (unlikely(ret != -ENOSPC))
return ret;
ret = ttm_mem_evict_first(bdev, man, place, ctx,
@@ -783,7 +785,7 @@ int ttm_bo_mem_space(struct ttm_buffer_object *bo,

type_found = true;
ret = ttm_resource_alloc(bo, place, mem);
- if (ret == -ENOSPC)
+ if (ret == -ENOSPC || ret == -EAGAIN)
continue;
if (unlikely(ret))
goto error;
--
2.34.1