379
Using buffer size of 2000.000MiB
Measuring idle latencies (in ns)...
Numa node
Numa node
0
1
0
84.2 141.4
1
141.5
82.4
• --latency_matrix prints a matrix of local and cross-socket memory
latencies.
• -e means that the hardware prefetcher states do not get modified.
• -r is random access reads for latency thread.
MLC can be used to test persistent memory latency and bandwidth in either DAX or
FSDAX modes. Commonly used arguments include
• -L requests that large pages (2MB) be used (assuming they have been
enabled).
• -h requests huge pages (1GB) for DAX file mapping.
• -J specifies a directory in which files for mmap will be created (by
default no files are created). This option is mutually exclusive with –j.
• -P CLFLUSH is used to evict stores to persistent memory.
Examples:
Sequential read latency:
# mlc_avx512 --idle_latency –J/mnt/pmemfs
Random read latency:
# mlc_avx512 --idle_latency -l256 –J/mnt/pmemfs
Chapter 19 advanCed topiCs