On 12/20/21 7:19 AM, Jens Axboe wrote: >>> develop NVMe/RDMA queue_rqs code and test the perf with it. >>> You should just be able to use iodepth_batch with fio. For my peak >>> testing, I use t/io_uring from the fio repo. By default, it'll run QD of >>> and do batches of 32 for complete and submit. You can just run: >>> >>> t/io_uring <dev or file> >>> >>> maybe adding -p0 for IRQ driven rather than polled IO. >> >> I used your block/for-next branch and implemented queue_rqs in NVMe/RDMA >> but it was never called using the t/io_uring test nor fio with >> iodepth_batch=32 flag with io_uring engine. >> >> Any idea what might be the issue ? >> >> I installed fio from sources.. > > The two main restrictions right now are a scheduler and shared tags, are > you using any of those? Here's a sample run, which is 2 threads, each driving 2 devices and using 31 (-s31) batch submit count, with 16 batch completions (-c16). Block size is 512b. Ignore most other options, they don't really matter, the defaults are 128 QD, 32 submit batch, 32 complete batch. $ sudo taskset -c 10,11 t/io_uring -d256 -b512 -s31 -c16 -p1 -F1 -B1 -n2 /dev/nvme0n1 /dev/nvme3n1 /dev/nvme2n1 /dev/nvme4n1 Added file /dev/nvme0n1 (submitter 0) Added file /dev/nvme3n1 (submitter 1) Added file /dev/nvme2n1 (submitter 0) Added file /dev/nvme4n1 (submitter 1) polled=1, fixedbufs=1/1, register_files=1, buffered=0, QD=256 Engine=io_uring, sq_ring=256, cq_ring=256 submitter=0, tid=91490 submitter=1, tid=91491 IOPS=13038K, BW=6366MiB/s, IOS/call=30/30, inflight=(128 5 120 128) IOPS=13042K, BW=6368MiB/s, IOS/call=30/30, inflight=(128 96 128 15) IOPS=13049K, BW=6371MiB/s, IOS/call=30/30, inflight=(128 122 120 128) IOPS=13045K, BW=6369MiB/s, IOS/call=30/30, inflight=(110 128 99 128) That's driving 13M IOPS, using a single CPU core (10/11 are thread siblings). Top of profile for that: + 6.41% io_uring [kernel.vmlinux] [k] __blk_mq_alloc_requests + 5.46% io_uring [kernel.vmlinux] [k] blkdev_direct_IO.part.0 + 5.36% io_uring [kernel.vmlinux] [k] blk_mq_end_request_batch + 5.24% io_uring io_uring [.] submitter_uring_fn + 5.18% io_uring [kernel.vmlinux] [k] io_submit_sqes + 5.12% io_uring [kernel.vmlinux] [k] bio_alloc_kiocb + 4.75% io_uring [nvme] [k] nvme_poll + 4.67% io_uring [kernel.vmlinux] [k] __io_import_iovec + 4.58% io_uring [nvme] [k] nvme_queue_rqs + 4.49% io_uring [kernel.vmlinux] [k] blk_mq_submit_bio + 4.32% io_uring [nvme] [k] nvme_map_data + 3.02% io_uring [kernel.vmlinux] [k] io_issue_sqe + 2.89% io_uring [nvme_core] [k] nvme_setup_cmd + 2.60% io_uring [kernel.vmlinux] [k] io_prep_rw + 2.59% io_uring [kernel.vmlinux] [k] submit_bio_noacct.part.0 -- Jens Axboe
