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