PMEM 2M aligned issue - Githubissues

Intel-bigdata / Spark-PMoF

Spark Shuffle Optimization with RDMA+AEP

Apache License 2.0

30 stars 22 forks source link

PMEM 2M aligned issue #16

Open tanghaodong25 opened 5 years ago

tanghaodong25 commented 5 years ago

If the pmem is mounted as 2M aligned, the pmem obj address can't be registered as rdma buffer. We need to mount pmem as 4K aligned, but the pmem write performance is worse than it with 2M aligned.

2M aligned (default) ndctl create-namespace -r region0 -f -e namespace0.0 -m devdax 4K aligned ndctl create-namespace -r region0 -f -e namespace0.0 -m devdax -a 4k

zhouyuan commented 5 years ago

we could set the alignment at pool level: https://github.com/pbalcer/nvml/blob/6f2136f379c9a44ad73315ab2075fe665e02bcf7/src/test/obj_ctl_alignment/obj_ctl_alignment.c