During some lock debugging on a dual-core Linux system I noticed that threads are blocked acquiring `cs_vNodes` and `cs_main` for long periods when the system is under moderate load from unrelated processes -- the unlucky lock acquirer is waiting for single-digit seconds once every 10 minutes or so (not coinciding with new blocks) up to around a 30 second wait every few hours. It looks like `ThreadMessageHandler` is taking locks and then due to being set to `THREAD_PRIORITY_BELOW_NORMAL`, it's being descheduled (even in trivial lock-holding regions like `GetHeight`) and holding up for arbitrarily long periods other threads that use these core locks.

So I'm wondering, what are the benefits of running the message handler at low priority?

{
    namespace fs = boost::filesystem;
    char pszPath[MAX_PATH] = "";
    if(SHGetSpecialFolderPathA(NULL, pszPath, nFolder, fCreate))
    {
        return fs::path(pszPath);
    }
    LogPrintf("SHGetSpecialFolderPathA() failed, could not obtain requested path.\n");
    return fs::path("");
}
#endif
void runCommand(const std::string& strCommand)