hi all, next bunch of kernel config changes. i did series of tests with lmbench disable next part of performance-wise options in kernel config. I archived very fast result. For example, top average CPU usage were dropped down from 3.2% with default config kernel to 1.6% average.
test environment: debian on sd, andy-tracking kernel with default config (gta02_moredrivers_defconfig) for gta02 + plus one feature changed. all tests were run several times Features changed as in summary report: 1. defconfig - default config 2. nodebug - debugging off : all except "Enable dynamic printk() call support" and "timing info" 3. speed - use -O2 optimization instead of -Os 4. nopreempt - disable preemtion (CONFIG_PREEMPT) test results: see http://www.bsdmn.com/openmoko/summary1.txt comments: file operations should be ignored, variuos memcpys and cache speeds can be used to mae sure that tests are comparable and system is ok. iterpretation: 1. debug impact is huge - 10x in open/close test, 13% on select, 10x on signal hadling, 2x on exec, 2x on fork, 1,8x on context switches. 50% on pipe latency, 30% on local TCP, 30% on pipes. system feel much faster. 2. preemption disable: smaller scale speedups, but also seem very noticeable. 3. optimising for speed have some impact in different areas, + and -, 0 in total, but much things were not tested. comclusion: so i propose to: 1) disable debugging for sure. 2) disable preemtion. 3) disable optimization for speed. gennady
