Hello, I have seen the discussions about fastlock patch and lazy-vxid performance degradation, so I decided to test it myself.
The setup: - hardware Supermicro blade 6xSAS @15k on LSI RAID: 1 disk for system + pg_xlog 4 disk RAID 10 for data 1 disk for spare 2 x Xeon E5405 @2GHz (no HT), 8 cores total 8G RAM - software Debian Sid, linux-2.6.39.1 Postgresql 9.1 beta2, compiled by debian sources incrementally applied fastlock v3 and lazy-vxid v1 patches. I have to resolve manually a conflict in src/backend/storage/lmgr/proc.c Configuration: increased shared_mem to 2G, max_connections to 500 - pgbench initiated datasert with scaling factor 100 example command invocation: ./pgbench -h 127.0.0.1 -n -S -T 30 -c 8 -j 8 -M prepared pgtest Results: clients beta2 +fastlock +lazyvzid local socket 8 76064 92430 92198 106734 16 64254 90788 90698 105097 32 56629 88189 88269 101202 64 51124 84354 84639 96362 128 45455 79361 79724 90625 256 40370 71904 72737 82434 All runs are executed on warm cache, I made some runs for 300s with the same results (tps). I have done some runs with -M simple with identical distribution across cleints. I post this results because they somehow contradict with previous results posted on the list. In my case the patches does not only improve peak performance but also improve the performance under load - without patches the performance with 256 clients is 53% of the peak performance that is obtained with 8 clients, with patches the performance with 256 client is 79% of the peak with 8 clients. Best regards Luben Karavelov P.S. Excuse me for starting new thread - I am new on the list.
