The problem has disappeared by itself after downgrade CryptoPP version 5.5.2 to 5.2.0
Now the speed of hashing is ranging from 30 MB/min up to 120 MB/min, depending on if rtorrent is active and if active how busy it(rtorrent) is and WITHOUT any system slowdowns.
BTW, I also carried out an experiment with new CryptoPP version 5.6, but the result was even worse - the hashing thread of aMuled used CPU at 80%...90% with full system slow downs.
Why the hashing thread of aMuled with newer versions of CryptoPP tried to act as real-time process not letting any other processes and even the system to use CPU in concurrent manner remains for me to complete mystery.
Stu Redman
There is NO predefined __powerpc__ for Linux target platforms in my crosstoolchains, it is predefined only for BSD.
freddy77
Thanks for mmap patch.
While it does not affect the CPU load in my case, but it is useful for memory usage - now aMuled try to use memory in wave-like manner.