[PATCH/RFC 16/16] perf tools: Skip dso front cache for multi-threaded lookup

Currently the dso maintains a front cache for faster symbol lookup, but access to it should be synchronized when multi thread is used. Also it doesn't help much if data file has callchains since it should walk through the callchains for each sample so single cache is almost meaningless. So skip

[PATCH/RFC 16/16] perf tools: Skip dso front cache for multi-threaded lookup

Currently the dso maintains a front cache for faster symbol lookup, but access to it should be synchronized when multi thread is used. Also it doesn't help much if data file has callchains since it should walk through the callchains for each sample so single cache is almost meaningless. So skip