From: Yevgeny Kliteynik Date: Wed, 25 May 2022 22:52:43 +0000 (+0300) Subject: net/mlx5: DR, Keep track of hot ICM chunks in an array instead of list X-Git-Tag: v6.6.7~3913^2~338^2~1 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4519fc45beebcb05a052ea631d22c85e3ab5665d;p=platform%2Fkernel%2Flinux-starfive.git net/mlx5: DR, Keep track of hot ICM chunks in an array instead of list When ICM chunk is freed, it might still be accessed by HW until we do sync with HW. This sync is expensive operation, so we don't do it often. Instead, when the chunk is freed, it is moved to the buddy's "hot memory" list. Once sync is done, we traverse the hot list and finally free all the chunks. It appears that traversing a long list takes unusually long time due to cache misses on many entries, which causes a big "hiccup" during rule insertion. This patch deals with this issue the following way: - Move hot chunks list from buddy to pool, so that the pool will keep track of all its hot memory. - Replace the list with pre-allocated array on the memory pool struct, and store only the information that is needed to later free this chunk in its buddy allocator. This cost additional memory for the array that is dynamically allocated, but it allows not to save long list of hot chunks, so at peak times it actually saves memory due to the fact that each array entry is much smaller than the chunk struct. This way an overhead of traversing the long list is virtually removed: the loop of freeing hot chunks takes ~27 msec instead of ~70 msec, where most of it are the actual freeing activities. Signed-off-by: Yevgeny Kliteynik Reviewed-by: Alex Vesker Signed-off-by: Saeed Mahameed --- diff --git a/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_buddy.c b/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_buddy.c index 7df11a01..7e30dc6 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_buddy.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_buddy.c @@ -16,7 +16,6 @@ int mlx5dr_buddy_init(struct mlx5dr_icm_buddy_mem *buddy, INIT_LIST_HEAD(&buddy->list_node); INIT_LIST_HEAD(&buddy->used_list); - INIT_LIST_HEAD(&buddy->hot_list); buddy->bitmap = kcalloc(buddy->max_order + 1, sizeof(*buddy->bitmap), diff --git a/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_icm_pool.c b/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_icm_pool.c index 286b7ce..c31608a 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_icm_pool.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_icm_pool.c @@ -6,6 +6,12 @@ #define DR_ICM_MODIFY_HDR_ALIGN_BASE 64 #define DR_ICM_POOL_HOT_MEMORY_FRACTION 4 +struct mlx5dr_icm_hot_chunk { + struct mlx5dr_icm_buddy_mem *buddy_mem; + unsigned int seg; + enum mlx5dr_icm_chunk_size size; +}; + struct mlx5dr_icm_pool { enum mlx5dr_icm_type icm_type; enum mlx5dr_icm_chunk_size max_log_chunk_sz; @@ -15,6 +21,13 @@ struct mlx5dr_icm_pool { /* memory management */ struct mutex mutex; /* protect the ICM pool and ICM buddy */ struct list_head buddy_mem_list; + + /* Hardware may be accessing this memory but at some future, + * undetermined time, it might cease to do so. + * sync_ste command sets them free. + */ + struct mlx5dr_icm_hot_chunk *hot_chunks_arr; + u32 hot_chunks_num; u64 hot_memory_size; }; @@ -286,9 +299,6 @@ static void dr_icm_buddy_destroy(struct mlx5dr_icm_buddy_mem *buddy) { struct mlx5dr_icm_chunk *chunk, *next; - list_for_each_entry_safe(chunk, next, &buddy->hot_list, chunk_list) - dr_icm_chunk_destroy(chunk); - list_for_each_entry_safe(chunk, next, &buddy->used_list, chunk_list) dr_icm_chunk_destroy(chunk); @@ -347,10 +357,28 @@ static bool dr_icm_pool_is_sync_required(struct mlx5dr_icm_pool *pool) return pool->hot_memory_size > allow_hot_size; } +static void dr_icm_pool_clear_hot_chunks_arr(struct mlx5dr_icm_pool *pool) +{ + struct mlx5dr_icm_hot_chunk *hot_chunk; + u32 i, num_entries; + + for (i = 0; i < pool->hot_chunks_num; i++) { + hot_chunk = &pool->hot_chunks_arr[i]; + num_entries = mlx5dr_icm_pool_chunk_size_to_entries(hot_chunk->size); + mlx5dr_buddy_free_mem(hot_chunk->buddy_mem, + hot_chunk->seg, ilog2(num_entries)); + hot_chunk->buddy_mem->used_memory -= + mlx5dr_icm_pool_chunk_size_to_byte(hot_chunk->size, + pool->icm_type); + } + + pool->hot_chunks_num = 0; + pool->hot_memory_size = 0; +} + static int dr_icm_pool_sync_all_buddy_pools(struct mlx5dr_icm_pool *pool) { struct mlx5dr_icm_buddy_mem *buddy, *tmp_buddy; - u32 num_entries; int err; err = mlx5dr_cmd_sync_steering(pool->dmn->mdev); @@ -359,16 +387,9 @@ static int dr_icm_pool_sync_all_buddy_pools(struct mlx5dr_icm_pool *pool) return err; } - list_for_each_entry_safe(buddy, tmp_buddy, &pool->buddy_mem_list, list_node) { - struct mlx5dr_icm_chunk *chunk, *tmp_chunk; - - list_for_each_entry_safe(chunk, tmp_chunk, &buddy->hot_list, chunk_list) { - num_entries = mlx5dr_icm_pool_get_chunk_num_of_entries(chunk); - mlx5dr_buddy_free_mem(buddy, chunk->seg, ilog2(num_entries)); - pool->hot_memory_size -= mlx5dr_icm_pool_get_chunk_byte_size(chunk); - dr_icm_chunk_destroy(chunk); - } + dr_icm_pool_clear_hot_chunks_arr(pool); + list_for_each_entry_safe(buddy, tmp_buddy, &pool->buddy_mem_list, list_node) { if (!buddy->used_memory && pool->icm_type == DR_ICM_TYPE_STE) dr_icm_buddy_destroy(buddy); } @@ -459,12 +480,24 @@ void mlx5dr_icm_free_chunk(struct mlx5dr_icm_chunk *chunk) { struct mlx5dr_icm_buddy_mem *buddy = chunk->buddy_mem; struct mlx5dr_icm_pool *pool = buddy->pool; + struct mlx5dr_icm_hot_chunk *hot_chunk; + struct kmem_cache *chunks_cache; + + chunks_cache = pool->chunks_kmem_cache; - /* move the memory to the waiting list AKA "hot" */ + /* move the chunk to the waiting chunks array, AKA "hot" memory */ mutex_lock(&pool->mutex); - list_move_tail(&chunk->chunk_list, &buddy->hot_list); + pool->hot_memory_size += mlx5dr_icm_pool_get_chunk_byte_size(chunk); + hot_chunk = &pool->hot_chunks_arr[pool->hot_chunks_num++]; + hot_chunk->buddy_mem = chunk->buddy_mem; + hot_chunk->seg = chunk->seg; + hot_chunk->size = chunk->size; + + list_del(&chunk->chunk_list); + kmem_cache_free(chunks_cache, chunk); + /* Check if we have chunks that are waiting for sync-ste */ if (dr_icm_pool_is_sync_required(pool)) dr_icm_pool_sync_all_buddy_pools(pool); @@ -485,6 +518,7 @@ void mlx5dr_icm_pool_free_htbl(struct mlx5dr_icm_pool *pool, struct mlx5dr_ste_h struct mlx5dr_icm_pool *mlx5dr_icm_pool_create(struct mlx5dr_domain *dmn, enum mlx5dr_icm_type icm_type) { + u32 num_of_chunks, entry_size, max_hot_size; enum mlx5dr_icm_chunk_size max_log_chunk_sz; struct mlx5dr_icm_pool *pool; @@ -506,16 +540,37 @@ struct mlx5dr_icm_pool *mlx5dr_icm_pool_create(struct mlx5dr_domain *dmn, mutex_init(&pool->mutex); + entry_size = mlx5dr_icm_pool_dm_type_to_entry_size(pool->icm_type); + + max_hot_size = mlx5dr_icm_pool_chunk_size_to_byte(pool->max_log_chunk_sz, + pool->icm_type) / + DR_ICM_POOL_HOT_MEMORY_FRACTION; + + num_of_chunks = DIV_ROUND_UP(max_hot_size, entry_size) + 1; + + pool->hot_chunks_arr = kvcalloc(num_of_chunks, + sizeof(struct mlx5dr_icm_hot_chunk), + GFP_KERNEL); + if (!pool->hot_chunks_arr) + goto free_pool; + return pool; + +free_pool: + kvfree(pool); + return NULL; } void mlx5dr_icm_pool_destroy(struct mlx5dr_icm_pool *pool) { struct mlx5dr_icm_buddy_mem *buddy, *tmp_buddy; + dr_icm_pool_clear_hot_chunks_arr(pool); + list_for_each_entry_safe(buddy, tmp_buddy, &pool->buddy_mem_list, list_node) dr_icm_buddy_destroy(buddy); + kvfree(pool->hot_chunks_arr); mutex_destroy(&pool->mutex); kvfree(pool); } diff --git a/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_types.h b/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_types.h index b645c0a..bd2c307 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_types.h +++ b/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_types.h @@ -147,6 +147,7 @@ struct mlx5dr_rule_rx_tx; struct mlx5dr_matcher_rx_tx; struct mlx5dr_ste_ctx; struct mlx5dr_send_info_pool; +struct mlx5dr_icm_hot_chunk; struct mlx5dr_ste { /* refcount: indicates the num of rules that using this ste */ diff --git a/drivers/net/ethernet/mellanox/mlx5/core/steering/mlx5dr.h b/drivers/net/ethernet/mellanox/mlx5/core/steering/mlx5dr.h index 226a0d7..674efb3 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/steering/mlx5dr.h +++ b/drivers/net/ethernet/mellanox/mlx5/core/steering/mlx5dr.h @@ -168,12 +168,6 @@ struct mlx5dr_icm_buddy_mem { struct list_head used_list; u64 used_memory; - /* Hardware may be accessing this memory but at some future, - * undetermined time, it might cease to do so. - * sync_ste command sets them free. - */ - struct list_head hot_list; - /* Memory optimisation */ struct mlx5dr_ste *ste_arr; struct list_head *miss_list;