I ran another benchmark today.
I choice dbench because dbench is one of most famous and real workload like i/o benchmark.
% dbench client.txt 4000
mainline: Throughput 13.4231 MB/sec 4000 clients 4000 procs max_latency=1421988.159 ms
mmotm(*): Throughput 7.0354 MB/sec 4000 clients 4000 procs max_latency=2369213.380 ms
(*) mmotm 2/Oct + Hugh's recently slub fix
Wow!
mmotm is slower than mainline largely (about half performance).
Therefore, I mesured it on "mainline + split-lru(only)" build.
mainline + split-lru(only): Throughput 14.4062 MB/sec 4000 clients 4000 procs max_latency=1152231.896 ms
OK!
split-lru outperform mainline from viewpoint of both throughput and latency :)
However, I don't understand why this regression happend.
Do you have any suggestion?
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