Hi -- I have been running some experiments involving processes sending large volumes of data concurrently. The results show (on Linux 2.6.19.2) that although the total throughput achieved by all the processes remains constant, the jitter increases as the number of processes increases. Beyond about 64 processes (on a 2.4GHz Xeon with 4Mb of cache), processes start getting starved and the streams get very bursty. What steps can one take to ensure that CPU allocation to processes transmitting concurrent packets be equitable? I'm using the default CPU scheduler, and the processes are using best effort to send the data. I guess that it is reasonable that the jitter grow with added contention through the TCP/IP stack - but what growth rate is acceptable? Is the data I have below reasonable? The jitter varies as follows and is shown as an average+/- sd across 25 10-second intervals. Concurrency Jitter (us) 1 1.6+/-0.8 2 1.5+/-1.1 4 1.4+/-0.6 8 0.8+/-0.5 12 2.3+/-1.2 16 3.3+/-2.1 20 4.6+/-2.5 24 6.2+/-1.4 28 7.8+/-3.2 32 10.0+/-3.4 64 100+ Sen - To unsubscribe from this list: send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
