From: Yu Kuai <yukuai3@xxxxxxxxxx> patch 1 is a small problem found by code review. patch 2 avoid holding resync_lock in fast path. patch 3 avoid holding lock in wake_up() in fast path. Test environment: Architecture: aarch64 Cpu: Huawei KUNPENG 920, there are four numa nodes Raid10 initialize: mdadm --create /dev/md0 --level 10 --bitmap none --raid-devices 4 /dev/nvme0n1 /dev/nvme1n1 /dev/nvme2n1 /dev/nvme3n1 Test cmd: fio -name=0 -ioengine=libaio -direct=1 -group_reporting=1 -randseed=2022 -rwmixread=70 -refill_buffers -filename=/dev/md0 -numjobs=16 -runtime=60s -bs=4k -iodepth=256 -rw=randread Test result: before this patchset: 2.9 GiB/s after this patchset: 6.6 Gib/s Please noted that in kunpeng-920, memory access latency is very bad accross nodes compare to local node, and in other architecture performance improvement might not be significant. Yu Kuai (3): md/raid10: fix improper BUG_ON() in raise_barrier() md/raid10: convert resync_lock to use seqlock md/raid10: prevent unnecessary calls to wake_up() in fast path drivers/md/raid10.c | 88 +++++++++++++++++++++++++++++---------------- drivers/md/raid10.h | 2 +- 2 files changed, 59 insertions(+), 31 deletions(-) -- 2.31.1
