From e1b5d28c8b22db50f30f61e905ec3635188b00f2 Mon Sep 17 00:00:00 2001 From: Changpeng Liu Date: Thu, 7 Apr 2022 10:58:45 +0800 Subject: [PATCH] bdev/nvme: set `max_segment_size` and `max_num_segments` Maximum Data Transfer Size indicates the maximum data transfer size for a command that transfers data between memory and the controller. SPDK NVMe driver will split IO request based on MDTS and stripe boundary, however, if user submited a big enough IO size, SPDK NVMe driver will run out of requests data structure and return -EINVAL as the error code, it's OK for application who call SPDK NVMe driver directly. SPDK bdev module also will do similar split based on `max_segment_size` and `max_num_segments`, but we don't set them for bdev/nvme driver, once there was a big enough IO request, the NVMe driver will return -EINVAL to bdev module, here we set `max_segment_size` based on MDTS and set `max_num_segments` based on number of requests of NVMe controller. Fix #2403. Change-Id: Ic6e14a0b12413783597122285ac648b87e1f1e16 Signed-off-by: Changpeng Liu Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/12186 Community-CI: Broadcom CI Community-CI: Mellanox Build Bot Tested-by: SPDK CI Jenkins Reviewed-by: Jim Harris Reviewed-by: Shuhei Matsumoto --- module/bdev/nvme/bdev_nvme.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/module/bdev/nvme/bdev_nvme.c b/module/bdev/nvme/bdev_nvme.c index c1bfe5e14..0110694c9 100644 --- a/module/bdev/nvme/bdev_nvme.c +++ b/module/bdev/nvme/bdev_nvme.c @@ -2871,11 +2871,13 @@ nvme_disk_create(struct spdk_bdev *disk, const char *base_name, const uint8_t *nguid; const struct spdk_nvme_ctrlr_data *cdata; const struct spdk_nvme_ns_data *nsdata; + const struct spdk_nvme_ctrlr_opts *opts; enum spdk_nvme_csi csi; uint32_t atomic_bs, phys_bs, bs; cdata = spdk_nvme_ctrlr_get_data(ctrlr); csi = spdk_nvme_ns_get_csi(ns); + opts = spdk_nvme_ctrlr_get_opts(ctrlr); switch (csi) { case SPDK_NVME_CSI_NVM: @@ -2910,6 +2912,16 @@ nvme_disk_create(struct spdk_bdev *disk, const char *base_name, } disk->blocklen = spdk_nvme_ns_get_extended_sector_size(ns); disk->blockcnt = spdk_nvme_ns_get_num_sectors(ns); + disk->max_segment_size = spdk_nvme_ctrlr_get_max_xfer_size(ctrlr); + /* NVMe driver will split one request into multiple requests + * based on MDTS and stripe boundary, the bdev layer will use + * max_segment_size and max_num_segments to split one big IO + * into multiple requests, then small request can't run out + * of NVMe internal requests data structure. + */ + if (opts && opts->io_queue_requests) { + disk->max_num_segments = opts->io_queue_requests / 2; + } disk->optimal_io_boundary = spdk_nvme_ns_get_optimal_io_boundary(ns); nguid = spdk_nvme_ns_get_nguid(ns);