On Fri, Mar 10, 2006 at 09:43:04PM +0800, Fuxin Zhang wrote: > Thiemo Seufer 写道: > > Can you provide information about the performance impact? That is, > > what system(s) you use, and some basic benchmark numbers. Did you also > > try 64k pages? > The system is running debian sarge,with a mips like Chinese 4-way > superscalar CPU and marvell 64240 system bridge, 256M sdram.Maybe > related information: this CPU has 64K 4-way dcache/icache，so cache > alias exists with 4K configuration. > > Big page size helps a bit with at least computational programs, such as > SPEC CPU2000 benchmarks. The attached jpg is a graph showing the results > of some SPEC programs under different page sizes. But we have not > benchmarked other workloads. 16K page size is used mainly to avoid cache > alias, which caused us too much time. > > Yes, with 64k more patches needed(some "short" field overflow?I don't > remember the exact modifications,other guys did it) There is more to large pages than just improved performance. They'll also save 75% memory for mem_map, will eleminate cache aliases in a bulletproof way. And will make allocation of memory larger than 4kB reliable - this especially is a big bonus with ethernet jumboframes with some NICs. Ralf
