On Tue, Jan 12, 2010 at 02:20:02PM +0800, zhihui Chen wrote: > Application can be categoried into CPU-sensitive, Memory-sensitive, > IO-sensitive.
My concern here is that unless the customer knows how to determine whether his application is CPU, memory, or IO sensitive it's going to be hard to use the tools well. > When CPU trigged one LLC miss, the data can be gotten from local > memory, cache or memory in remote node. Generlly, the latency for > local memory will be close to latency for remote cache, while latency > for remote memory should be much higher. This isn't universally true. On some SPARC platforms, it actually takes longer to read a line out of a remote CPU's cache than it does to access the memory on a remote system board. On a large system, many CPU's may have this address in their cache, and they all need to know that it has become owned by the reading CPU. If you're going to make this tool work on SPARC, it won't always be safe to make this assumption. -j _______________________________________________ perf-discuss mailing list perf-discuss@opensolaris.org
