Move ublk_add_tag_set() before ublk_init_queues() in the device initialization path. This allows us to use the blk-mq CPU-to-queue mapping established by the tag_set to determine the appropriate NUMA node for each queue allocation. The error handling paths are also reordered accordingly. Reviewed-by: Caleb Sander Mateos Signed-off-by: Ming Lei --- drivers/block/ublk_drv.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 0c74a41a6753..2569566bf5e6 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -3178,17 +3178,17 @@ static int ublk_ctrl_add_dev(const struct ublksrv_ctrl_cmd *header) ub->dev_info.nr_hw_queues, nr_cpu_ids); ublk_align_max_io_size(ub); - ret = ublk_init_queues(ub); + ret = ublk_add_tag_set(ub); if (ret) goto out_free_dev_number; - ret = ublk_add_tag_set(ub); + ret = ublk_init_queues(ub); if (ret) - goto out_deinit_queues; + goto out_free_tag_set; ret = -EFAULT; if (copy_to_user(argp, &ub->dev_info, sizeof(info))) - goto out_free_tag_set; + goto out_deinit_queues; /* * Add the char dev so that ublksrv daemon can be setup. @@ -3197,10 +3197,10 @@ static int ublk_ctrl_add_dev(const struct ublksrv_ctrl_cmd *header) ret = ublk_add_chdev(ub); goto out_unlock; -out_free_tag_set: - blk_mq_free_tag_set(&ub->tag_set); out_deinit_queues: ublk_deinit_queues(ub); +out_free_tag_set: + blk_mq_free_tag_set(&ub->tag_set); out_free_dev_number: ublk_free_dev_number(ub); out_free_ub: -- 2.47.0 Implement NUMA-friendly memory allocation for ublk driver to improve performance on multi-socket systems. This commit includes the following changes: 1. Convert struct ublk_device to use a flexible array member for the queues field instead of a separate pointer array allocation. This eliminates one level of indirection and simplifies memory management. The queues array is now allocated as part of struct ublk_device using struct_size(). 2. 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. 3. Remove the queue_size field from struct ublk_device as it is no longer needed. 4. 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. 5. 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. 6. Allocate each queue structure on its local NUMA node using kvzalloc_node() in ublk_init_queue(). 7. 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..ed77b4527b33 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[] __counted_by(dev_info.nr_hw_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 Convert ublk_queue to use struct_size() for allocation. Changes in this commit: 1. Update ublk_init_queue() to use struct_size(ubq, ios, depth) instead of manual size calculation (sizeof(struct ublk_queue) + depth * sizeof(struct ublk_io)). This provides better type safety and makes the code more maintainable by using standard kernel macro for flexible array handling. Meantime annotate ublk_queue.ios by __counted_by(). Signed-off-by: Ming Lei --- drivers/block/ublk_drv.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index ed77b4527b33..409874714c62 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -203,7 +203,7 @@ struct ublk_queue { bool fail_io; /* copy of dev->state == UBLK_S_DEV_FAIL_IO */ spinlock_t cancel_lock; struct ublk_device *dev; - struct ublk_io ios[]; + struct ublk_io ios[] __counted_by(q_depth); }; struct ublk_device { @@ -2700,7 +2700,6 @@ static int ublk_get_queue_numa_node(struct ublk_device *ub, int q_id) static int ublk_init_queue(struct ublk_device *ub, int 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; struct ublk_queue *ubq; struct page *page; @@ -2711,7 +2710,8 @@ static int ublk_init_queue(struct ublk_device *ub, int q_id) 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); + ubq = kvzalloc_node(struct_size(ubq, ios, depth), GFP_KERNEL, + numa_node); if (!ubq) return -ENOMEM; -- 2.47.0 Move ublk_thread_set_sched_affinity() call before ublk_thread_init() to ensure memory allocations during thread initialization occur on the correct NUMA node. This leverages Linux's first-touch memory policy for better NUMA locality. Also convert ublk_thread_set_sched_affinity() to use pthread_setaffinity_np() instead of sched_setaffinity(), as the pthread API is the proper interface for setting thread affinity in multithreaded programs. Signed-off-by: Ming Lei --- tools/testing/selftests/ublk/kublk.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/ublk/kublk.c b/tools/testing/selftests/ublk/kublk.c index 6b8123c12a7a..062537ab8976 100644 --- a/tools/testing/selftests/ublk/kublk.c +++ b/tools/testing/selftests/ublk/kublk.c @@ -839,7 +839,7 @@ static int ublk_process_io(struct ublk_thread *t) static void ublk_thread_set_sched_affinity(const struct ublk_thread *t, cpu_set_t *cpuset) { - if (sched_setaffinity(0, sizeof(*cpuset), cpuset) < 0) + if (pthread_setaffinity_np(pthread_self(), sizeof(*cpuset), cpuset) < 0) ublk_err("ublk dev %u thread %u set affinity failed", t->dev->dev_info.dev_id, t->idx); } @@ -862,15 +862,21 @@ static void *ublk_io_handler_fn(void *data) t->dev = info->dev; t->idx = info->idx; + /* + * IO perf is sensitive with queue pthread affinity on NUMA machine + * + * Set sched_affinity at beginning, so following allocated memory/pages + * could be CPU/NUMA aware. + */ + if (info->affinity) + ublk_thread_set_sched_affinity(t, info->affinity); + ret = ublk_thread_init(t, info->extra_flags); if (ret) { ublk_err("ublk dev %d thread %u init failed\n", dev_id, t->idx); return NULL; } - /* IO perf is sensitive with queue pthread affinity on NUMA machine*/ - if (info->affinity) - ublk_thread_set_sched_affinity(t, info->affinity); sem_post(info->ready); ublk_dbg(UBLK_DBG_THREAD, "tid %d: ublk dev %d thread %u started\n", -- 2.47.0 Refactor ublk_thread to be a thread-local variable instead of storing it in ublk_dev: - Remove pthread_t thread field from struct ublk_thread and move it to struct ublk_thread_info - Remove struct ublk_thread array from struct ublk_dev, reducing memory footprint - Define struct ublk_thread as local variable in __ublk_io_handler_fn() instead of accessing it from dev->threads[] - Extract main IO handling logic into __ublk_io_handler_fn() which is marked as noinline - Move CPU affinity setup to ublk_io_handler_fn() before calling __ublk_io_handler_fn() - Update ublk_thread_set_sched_affinity() to take struct ublk_thread_info * instead of struct ublk_thread *, and use pthread_setaffinity_np() instead of sched_setaffinity() - Reorder struct ublk_thread fields to group related state together This change makes each thread's ublk_thread structure truly local to the thread, improving cache locality and reducing memory usage. Signed-off-by: Ming Lei --- tools/testing/selftests/ublk/kublk.c | 76 +++++++++++++++------------- tools/testing/selftests/ublk/kublk.h | 9 ++-- 2 files changed, 45 insertions(+), 40 deletions(-) diff --git a/tools/testing/selftests/ublk/kublk.c b/tools/testing/selftests/ublk/kublk.c index 062537ab8976..f8fa102a627f 100644 --- a/tools/testing/selftests/ublk/kublk.c +++ b/tools/testing/selftests/ublk/kublk.c @@ -836,62 +836,70 @@ static int ublk_process_io(struct ublk_thread *t) return reapped; } -static void ublk_thread_set_sched_affinity(const struct ublk_thread *t, - cpu_set_t *cpuset) -{ - if (pthread_setaffinity_np(pthread_self(), sizeof(*cpuset), cpuset) < 0) - ublk_err("ublk dev %u thread %u set affinity failed", - t->dev->dev_info.dev_id, t->idx); -} - struct ublk_thread_info { struct ublk_dev *dev; + pthread_t thread; unsigned idx; sem_t *ready; cpu_set_t *affinity; unsigned long long extra_flags; }; -static void *ublk_io_handler_fn(void *data) +static void ublk_thread_set_sched_affinity(const struct ublk_thread_info *info) { - struct ublk_thread_info *info = data; - struct ublk_thread *t = &info->dev->threads[info->idx]; + if (pthread_setaffinity_np(pthread_self(), sizeof(*info->affinity), info->affinity) < 0) + ublk_err("ublk dev %u thread %u set affinity failed", + info->dev->dev_info.dev_id, info->idx); +} + +static __attribute__((noinline)) int __ublk_io_handler_fn(struct ublk_thread_info *info) +{ + struct ublk_thread t = { + .dev = info->dev, + .idx = info->idx, + }; int dev_id = info->dev->dev_info.dev_id; int ret; - t->dev = info->dev; - t->idx = info->idx; - - /* - * IO perf is sensitive with queue pthread affinity on NUMA machine - * - * Set sched_affinity at beginning, so following allocated memory/pages - * could be CPU/NUMA aware. - */ - if (info->affinity) - ublk_thread_set_sched_affinity(t, info->affinity); - - ret = ublk_thread_init(t, info->extra_flags); + ret = ublk_thread_init(&t, info->extra_flags); if (ret) { ublk_err("ublk dev %d thread %u init failed\n", - dev_id, t->idx); - return NULL; + dev_id, t.idx); + return ret; } sem_post(info->ready); ublk_dbg(UBLK_DBG_THREAD, "tid %d: ublk dev %d thread %u started\n", - gettid(), dev_id, t->idx); + gettid(), dev_id, t.idx); /* submit all io commands to ublk driver */ - ublk_submit_fetch_commands(t); + ublk_submit_fetch_commands(&t); do { - if (ublk_process_io(t) < 0) + if (ublk_process_io(&t) < 0) break; } while (1); ublk_dbg(UBLK_DBG_THREAD, "tid %d: ublk dev %d thread %d exiting\n", - gettid(), dev_id, t->idx); - ublk_thread_deinit(t); + gettid(), dev_id, t.idx); + ublk_thread_deinit(&t); + return 0; +} + +static void *ublk_io_handler_fn(void *data) +{ + struct ublk_thread_info *info = data; + + /* + * IO perf is sensitive with queue pthread affinity on NUMA machine + * + * Set sched_affinity at beginning, so following allocated memory/pages + * could be CPU/NUMA aware. + */ + if (info->affinity) + ublk_thread_set_sched_affinity(info); + + __ublk_io_handler_fn(info); + return NULL; } @@ -989,14 +997,13 @@ static int ublk_start_daemon(const struct dev_ctx *ctx, struct ublk_dev *dev) */ if (dev->nthreads == dinfo->nr_hw_queues) tinfo[i].affinity = &affinity_buf[i]; - pthread_create(&dev->threads[i].thread, NULL, + pthread_create(&tinfo[i].thread, NULL, ublk_io_handler_fn, &tinfo[i]); } for (i = 0; i < dev->nthreads; i++) sem_wait(&ready); - free(tinfo); free(affinity_buf); /* everything is fine now, start us */ @@ -1019,7 +1026,8 @@ static int ublk_start_daemon(const struct dev_ctx *ctx, struct ublk_dev *dev) /* wait until we are terminated */ for (i = 0; i < dev->nthreads; i++) - pthread_join(dev->threads[i].thread, &thread_ret); + pthread_join(tinfo[i].thread, &thread_ret); + free(tinfo); fail: for (i = 0; i < dinfo->nr_hw_queues; i++) ublk_queue_deinit(&dev->q[i]); diff --git a/tools/testing/selftests/ublk/kublk.h b/tools/testing/selftests/ublk/kublk.h index 5e55484fb0aa..fe42705c6d42 100644 --- a/tools/testing/selftests/ublk/kublk.h +++ b/tools/testing/selftests/ublk/kublk.h @@ -175,23 +175,20 @@ struct ublk_queue { struct ublk_thread { struct ublk_dev *dev; - struct io_uring ring; - unsigned int cmd_inflight; - unsigned int io_inflight; - - pthread_t thread; unsigned idx; #define UBLKS_T_STOPPING (1U << 0) #define UBLKS_T_IDLE (1U << 1) unsigned state; + unsigned int cmd_inflight; + unsigned int io_inflight; + struct io_uring ring; }; struct ublk_dev { struct ublk_tgt tgt; struct ublksrv_ctrl_dev_info dev_info; struct ublk_queue q[UBLK_MAX_QUEUES]; - struct ublk_thread threads[UBLK_MAX_THREADS]; unsigned nthreads; unsigned per_io_tasks; -- 2.47.0