Messages in this thread | | | Date | Tue, 28 May 2002 17:11:04 +0530 | From | Dipankar Sarma <> | Subject | 8-CPU (SMP) #s for lockfree rtcache |
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Hi Dave,
Here are the SMP numbers that you had asked for. They were measured on an 8-CPU SMP box (PIII Xeon 700 MHz processors, 1MB L2 cache and 6GB RAM).
The test was as per your suggestion. rt_rcu is a patch that uses RCU to do lockfree lookup of ipv4 route cache.
The basic test sends a fixed number of packets to random destination addresses repeating every dest for 5 packets. We tried two configurations of this test - 8-1-32 where 32 test processes simultaneosly uses 32 different random seeds to generate different dest addreses and 8-4-8 where 8 sets, each consisting 4 processes all of whom use the same random seed generating the same dst addresses, send packets to the dest addresses repeating dest for every 5 packets.
With these basic tests, we measured under several other conditions - avoid forced neighbor table garbage collection by increasing the threshold and interval (to 31048576 and 60) and slowing the packet rate by introducing a delay of 2ms between bursts of 5 packets.
Here are the results in terms of profile counts in ip_route_output_key() - gc stands for neighbor table garbage collection adjustment and u2000 stands for 2ms packet rate delay. All measurements where done based on 2.5.3 kernel.
Test base rtrcu speedup ---- ---- ----- ------- 8-1-32 2358 1655 29.8% 8-1-32-gc 4486 2176 51.4% 8-1-32-u2000 2990 1942 35.0% 8-1-32-u2000-gc 4047 2029 49.8%
8-4-8 2870 1965 31.5% 8-4-8-gc 3389 2083 38.5% 8-4-8-u2000 3459 2373 31.3% 8-4-8-u2000-gc 4686 2603 44.4%
Thanks -- Dipankar Sarma <dipankar@in.ibm.com> http://lse.sourceforge.net Linux Technology Center, IBM Software Lab, Bangalore, India. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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