Introduction to LMbench Speaker: 陳雋中

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What is LMbench? Suite of simple, portable benchmarks It measures two key features: latency and bandwidth To transfer data between processor, cache, memory , network and disk Compares different systems performance Results available for most major vendors (SUN, HP, IBM, DEC, SGI, PCs

What is LMbench? (cont) Bandwidth benchmarks Cached file read Memory copy (bcopy) Memory read Memory write Pipe TCP Latency benchmarks Context switching. Networking: connection establishment, pipe, TCP, UDP, and RPC hot potato File system creates and deletes. Process creation. Signal handling System call overhead Memory read latency Miscellaneous Processor clock rate calculation

Memory latency results The memory latency test shows the latency of all of the system (data) caches, i.e., level 1, 2, and 3, if present, as well as main memory and TLB miss latency. In addition the sizes of the caches can be read off of a properly plotted set of results. The hardware folks like this. This benchmark has found bugs in operating system page coloring schemes. Context switching results Everybody seems to love context switching numbers. This particular benchmark is quite careful not to just quote the ``in cache'' numbers. It varies both the number and size of the procesess and plots the results in such a way that it is easy to see when you don't fit in the cache. You can also see the real costs of a cold cache context switch.

Start running Vary parameters to adjust different workload DEMO

Results(1/3) Basic system parameters

Results(2/3)

Results(3/3)

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