Am 24.04.24 um 18:57 schrieb Friedrich Vock:
This makes buffer eviction significantly more stable by avoiding
ping-ponging caused by low-priority buffers evicting high-priority
buffers and vice versa.
And creates a deny of service for the whole system by fork() bombing.
This is another very big NAK.
Regards,
Christian.
Signed-off-by: Friedrich Vock <friedrich.vock@xxxxxx>
---
drivers/gpu/drm/ttm/ttm_bo.c | 9 +++++++--
drivers/gpu/drm/ttm/ttm_resource.c | 5 +++--
include/drm/ttm/ttm_bo.h | 1 +
3 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 3047c763eb4eb..eae54cd4a7ce9 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -776,6 +776,7 @@ static int ttm_mem_evict_wait_busy(struct ttm_buffer_object *busy_bo,
int ttm_mem_evict_first(struct ttm_device *bdev,
struct ttm_resource_manager *man,
const struct ttm_place *place,
+ unsigned int max_priority,
struct ttm_operation_ctx *ctx,
struct ww_acquire_ctx *ticket)
{
@@ -788,6 +789,8 @@ int ttm_mem_evict_first(struct ttm_device *bdev,
spin_lock(&bdev->lru_lock);
ttm_resource_manager_for_each_res(man, &cursor, res) {
bool busy;
+ if (res->bo->priority > max_priority)
+ break;
if (!ttm_bo_evict_swapout_allowable(res->bo, ctx, place,
&locked, &busy)) {
@@ -930,8 +933,10 @@ static int ttm_bo_mem_force_space(struct ttm_buffer_object *bo,
return ret;
if (ctx->no_evict)
return -ENOSPC;
- ret = ttm_mem_evict_first(bdev, man, place, ctx,
- ticket);
+ if (!bo->priority)
+ return -ENOSPC;
+ ret = ttm_mem_evict_first(bdev, man, place, bo->priority - 1,
+ ctx, ticket);
if (unlikely(ret != 0))
return ret;
} while (1);
diff --git a/drivers/gpu/drm/ttm/ttm_resource.c b/drivers/gpu/drm/ttm/ttm_resource.c
index 1d6755a1153b1..63d4371adb519 100644
--- a/drivers/gpu/drm/ttm/ttm_resource.c
+++ b/drivers/gpu/drm/ttm/ttm_resource.c
@@ -431,8 +431,9 @@ int ttm_resource_manager_evict_all(struct ttm_device *bdev,
for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
while (!list_empty(&man->lru[i])) {
spin_unlock(&bdev->lru_lock);
- ret = ttm_mem_evict_first(bdev, man, NULL, &ctx,
- NULL);
+ ret = ttm_mem_evict_first(bdev, man, NULL,
+ TTM_MAX_BO_PRIORITY,
+ &ctx, NULL);
if (ret)
return ret;
spin_lock(&bdev->lru_lock);
diff --git a/include/drm/ttm/ttm_bo.h b/include/drm/ttm/ttm_bo.h
index 8f4e6366c0417..91299a3b6fcfa 100644
--- a/include/drm/ttm/ttm_bo.h
+++ b/include/drm/ttm/ttm_bo.h
@@ -396,6 +396,7 @@ void ttm_bo_unpin(struct ttm_buffer_object *bo);
int ttm_mem_evict_first(struct ttm_device *bdev,
struct ttm_resource_manager *man,
const struct ttm_place *place,
+ unsigned int max_priority,
struct ttm_operation_ctx *ctx,
struct ww_acquire_ctx *ticket);
void ttm_mem_unevict_evicted(struct ttm_device *bdev,
--
2.44.0
