From: Ming Lei <ming.lei@redhat.com>
To: linux-nvme@lists.infradead.org, Will Deacon <will@kernel.org>,
linux-arm-kernel@lists.infradead.org,
iommu@lists.linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Subject: [bug report] iommu_dma_unmap_sg() is very slow then running IO from remote numa node
Date: Fri, 9 Jul 2021 16:38:09 +0800 [thread overview]
Message-ID: <YOgK8fdv7dOQtkET@T590> (raw)
Hello,
I observed that NVMe performance is very bad when running fio on one
CPU(aarch64) in remote numa node compared with the nvme pci numa node.
Please see the test result[1] 327K vs. 34.9K.
Latency trace shows that one big difference is in iommu_dma_unmap_sg(),
1111 nsecs vs 25437 nsecs.
[1] fio test & results
1) fio test result:
- run fio on local CPU
taskset -c 0 ~/git/tools/test/nvme/io_uring 10 1 /dev/nvme1n1 4k
+ fio --bs=4k --ioengine=io_uring --fixedbufs --registerfiles --hipri --iodepth=64 --iodepth_batch_submit=16 --iodepth_batch_complete_min=16 --filename=/dev/nvme1n1 --direct=1 --runtime=10 --numjobs=1 --rw=randread --name=test --group_reporting
IOPS: 327K
avg latency of iommu_dma_unmap_sg(): 1111 nsecs
- run fio on remote CPU
taskset -c 80 ~/git/tools/test/nvme/io_uring 10 1 /dev/nvme1n1 4k
+ fio --bs=4k --ioengine=io_uring --fixedbufs --registerfiles --hipri --iodepth=64 --iodepth_batch_submit=16 --iodepth_batch_complete_min=16 --filename=/dev/nvme1n1 --direct=1 --runtime=10 --numjobs=1 --rw=randread --name=test --group_reporting
IOPS: 34.9K
avg latency of iommu_dma_unmap_sg(): 25437 nsecs
2) system info
[root@ampere-mtjade-04 ~]# lscpu | grep NUMA
NUMA node(s): 2
NUMA node0 CPU(s): 0-79
NUMA node1 CPU(s): 80-159
lspci | grep NVMe
0003:01:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd NVMe SSD Controller SM981/PM981/PM983
[root@ampere-mtjade-04 ~]# cat /sys/block/nvme1n1/device/device/numa_node
0
Thanks,
Ming
next reply other threads:[~2021-07-09 8:38 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-09 8:38 Ming Lei [this message]
2021-07-09 10:16 ` [bug report] iommu_dma_unmap_sg() is very slow then running IO from remote numa node Russell King (Oracle)
2021-07-09 14:21 ` Ming Lei
2021-07-09 10:26 ` Robin Murphy
2021-07-09 11:04 ` John Garry
2021-07-09 12:34 ` Robin Murphy
2021-07-09 14:24 ` Ming Lei
2021-07-19 16:14 ` John Garry
2021-07-21 1:40 ` Ming Lei
2021-07-21 9:23 ` John Garry
2021-07-21 9:59 ` Ming Lei
2021-07-21 11:07 ` John Garry
2021-07-21 11:58 ` Ming Lei
2021-07-22 7:58 ` Ming Lei
2021-07-22 10:05 ` John Garry
2021-07-22 10:19 ` Ming Lei
2021-07-22 11:12 ` John Garry
2021-07-22 12:53 ` Marc Zyngier
2021-07-22 13:54 ` John Garry
2021-07-22 15:54 ` Ming Lei
2021-07-22 17:40 ` Robin Murphy
2021-07-23 10:21 ` Ming Lei
2021-07-26 7:51 ` John Garry
2021-07-28 1:32 ` Ming Lei
2021-07-28 10:38 ` John Garry
2021-07-28 15:17 ` Ming Lei
2021-07-28 15:39 ` Robin Murphy
2021-08-10 9:36 ` John Garry
2021-08-10 10:35 ` Ming Lei
2021-07-27 17:08 ` Robin Murphy
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