Hi Eric, Suka, guys. I have tested the following configurations:
1. 2.6.21-mm2 kernel with Suka's patches with CONFIG_PID_NS=n 2. the same with CONFIG_PID_NS=y 3. 2.6.22-rc1-mm1 kernel with my own realisation (patches will be sent later if interesting) with CONFIG_PID_NS=n; 4. the same with CONFIG_PID_NS=y and flat model (OpenVZ view) I sent earlier; 5. the same with multilevel model of my own. The difference is that I use hash to lookup pid_elem from struct pid/pid_t nr, not a plain "for" loop like in Suka's patches. The tests run were: 1. Unixbench spawn test 2. Unixbench execl test 3. Unixbensh shell test 4. System time for ps -xaf run in a loop (1000 times) The hardware used is 2x Intel(R) Xeon(TM) CPU 3.20GHz box with 2Gb of RAM. All the results are reproducible with 0.1% accuracy. The slowdown is shown in comparison to the according results for CONFIG_PID_NS=n kernel. Summary: Suka's model gives us about 1.5% of overhead. My multilevel model gives us about 0.7% of overhead. My flat model gives us an overhead comparative to the accuracy of the measurement, i.e. zero overhead. The detailed results are the following: Test name: spawn execl shell ps (sys time) 1(no ns) : 579.1 618.3 1623.2 3.052s 2(suka's): 570.7 610.8 1600.2 3.107s Slowdown : 1.5% 1.3% 1.4% 1.8% 3(no ns) : 580.6 616.0 1633.8 3.050s 4(flat) : 580.8 615.1 1632.2 3.054s Slowdown : 0% 0.1% <0.1% 0.1% 5(multi) : 576.9 611.0 1618.8 3.065s Slowdown : 0.6% 0.8% 0.9% 0.5% For the first three tests the result is better the higher the number is. For the last test - the result is better the lower the number is (since it is a time spent in kernel). The results in the namespace may be worse. If you are interested I can send my patches for pre-review and cooperation. With the results shown I think the we do must have the flat model as an option in the kernel for those who don't need the infinite nesting, but cares for the kernel performance. Thanks, Pavel. _______________________________________________ Containers mailing list [EMAIL PROTECTED] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list Devel@openvz.org https://openvz.org/mailman/listinfo/devel
