Implement NUMA-friendly memory allocation for ublk driver to improve performance on multi-socket systems. This commit includes the following changes: 1. Rename __queues to queues, dropping the __ prefix since the field is now accessed directly throughout the codebase rather than only through the ublk_get_queue() helper. 2. Remove the queue_size field from struct ublk_device as it is no longer needed. 3. Move queue allocation and deallocation into ublk_init_queue() and ublk_deinit_queue() respectively, improving encapsulation. This simplifies ublk_init_queues() and ublk_deinit_queues() to just iterate and call the per-queue functions. 4. Add ublk_get_queue_numa_node() helper function to determine the appropriate NUMA node for a queue by finding the first CPU mapped to that queue via tag_set.map[HCTX_TYPE_DEFAULT].mq_map[] and converting it to a NUMA node using cpu_to_node(). This function is called internally by ublk_init_queue() to determine the allocation node. 5. Allocate each queue structure on its local NUMA node using kvzalloc_node() in ublk_init_queue(). 6. Allocate the I/O command buffer on the same NUMA node using alloc_pages_node(). This reduces memory access latency on multi-socket NUMA systems by ensuring each queue's data structures are local to the CPUs that access them. Reviewed-by: Caleb Sander Mateos Signed-off-by: Ming Lei --- drivers/block/ublk_drv.c | 84 +++++++++++++++++++++++++--------------- 1 file changed, 53 insertions(+), 31 deletions(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 2569566bf5e6..d920f7cf4dad 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -209,9 +209,6 @@ struct ublk_queue { struct ublk_device { struct gendisk *ub_disk; - char *__queues; - - unsigned int queue_size; struct ublksrv_ctrl_dev_info dev_info; struct blk_mq_tag_set tag_set; @@ -239,6 +236,8 @@ struct ublk_device { bool canceling; pid_t ublksrv_tgid; struct delayed_work exit_work; + + struct ublk_queue *queues[]; }; /* header of ublk_params */ @@ -781,7 +780,7 @@ static noinline void ublk_put_device(struct ublk_device *ub) static inline struct ublk_queue *ublk_get_queue(struct ublk_device *dev, int qid) { - return (struct ublk_queue *)&(dev->__queues[qid * dev->queue_size]); + return dev->queues[qid]; } static inline bool ublk_rq_has_data(const struct request *rq) @@ -2662,9 +2661,13 @@ static const struct file_operations ublk_ch_fops = { static void ublk_deinit_queue(struct ublk_device *ub, int q_id) { - int size = ublk_queue_cmd_buf_size(ub); - struct ublk_queue *ubq = ublk_get_queue(ub, q_id); - int i; + struct ublk_queue *ubq = ub->queues[q_id]; + int size, i; + + if (!ubq) + return; + + size = ublk_queue_cmd_buf_size(ub); for (i = 0; i < ubq->q_depth; i++) { struct ublk_io *io = &ubq->ios[i]; @@ -2676,57 +2679,76 @@ static void ublk_deinit_queue(struct ublk_device *ub, int q_id) if (ubq->io_cmd_buf) free_pages((unsigned long)ubq->io_cmd_buf, get_order(size)); + + kvfree(ubq); + ub->queues[q_id] = NULL; +} + +static int ublk_get_queue_numa_node(struct ublk_device *ub, int q_id) +{ + unsigned int cpu; + + /* Find first CPU mapped to this queue */ + for_each_possible_cpu(cpu) { + if (ub->tag_set.map[HCTX_TYPE_DEFAULT].mq_map[cpu] == q_id) + return cpu_to_node(cpu); + } + + return NUMA_NO_NODE; } static int ublk_init_queue(struct ublk_device *ub, int q_id) { - struct ublk_queue *ubq = ublk_get_queue(ub, q_id); + int depth = ub->dev_info.queue_depth; + int ubq_size = sizeof(struct ublk_queue) + depth * sizeof(struct ublk_io); gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO; - void *ptr; + struct ublk_queue *ubq; + struct page *page; + int numa_node; int size; + /* Determine NUMA node based on queue's CPU affinity */ + numa_node = ublk_get_queue_numa_node(ub, q_id); + + /* Allocate queue structure on local NUMA node */ + ubq = kvzalloc_node(ubq_size, GFP_KERNEL, numa_node); + if (!ubq) + return -ENOMEM; + spin_lock_init(&ubq->cancel_lock); ubq->flags = ub->dev_info.flags; ubq->q_id = q_id; - ubq->q_depth = ub->dev_info.queue_depth; + ubq->q_depth = depth; size = ublk_queue_cmd_buf_size(ub); - ptr = (void *) __get_free_pages(gfp_flags, get_order(size)); - if (!ptr) + /* Allocate I/O command buffer on local NUMA node */ + page = alloc_pages_node(numa_node, gfp_flags, get_order(size)); + if (!page) { + kvfree(ubq); return -ENOMEM; + } + ubq->io_cmd_buf = page_address(page); - ubq->io_cmd_buf = ptr; + ub->queues[q_id] = ubq; ubq->dev = ub; return 0; } static void ublk_deinit_queues(struct ublk_device *ub) { - int nr_queues = ub->dev_info.nr_hw_queues; int i; - if (!ub->__queues) - return; - - for (i = 0; i < nr_queues; i++) + for (i = 0; i < ub->dev_info.nr_hw_queues; i++) ublk_deinit_queue(ub, i); - kvfree(ub->__queues); } static int ublk_init_queues(struct ublk_device *ub) { - int nr_queues = ub->dev_info.nr_hw_queues; - int depth = ub->dev_info.queue_depth; - int ubq_size = sizeof(struct ublk_queue) + depth * sizeof(struct ublk_io); - int i, ret = -ENOMEM; + int i, ret; - ub->queue_size = ubq_size; - ub->__queues = kvcalloc(nr_queues, ubq_size, GFP_KERNEL); - if (!ub->__queues) - return ret; - - for (i = 0; i < nr_queues; i++) { - if (ublk_init_queue(ub, i)) + for (i = 0; i < ub->dev_info.nr_hw_queues; i++) { + ret = ublk_init_queue(ub, i); + if (ret) goto fail; } @@ -3128,7 +3150,7 @@ static int ublk_ctrl_add_dev(const struct ublksrv_ctrl_cmd *header) goto out_unlock; ret = -ENOMEM; - ub = kzalloc(sizeof(*ub), GFP_KERNEL); + ub = kzalloc(struct_size(ub, queues, info.nr_hw_queues), GFP_KERNEL); if (!ub) goto out_unlock; mutex_init(&ub->mutex); -- 2.47.0