I was toying with a scalable rw_mutex and found that it gives ~10% reduction in system time on ebizzy runs (without the MADV_FREE patch).
2-way x86_64 pentium D box: 2.6.21 /usr/bin/time ./ebizzy -m -P 60.10user 137.72system 1:49.59elapsed 180%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (0major+33555877minor)pagefaults 0swaps /usr/bin/time ./ebizzy -m -P 59.73user 139.50system 1:50.28elapsed 180%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (0major+33555878minor)pagefaults 0swaps /usr/bin/time ./ebizzy -m -P 59.49user 137.74system 1:49.22elapsed 180%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (0major+33555877minor)pagefaults 0swaps 2.6.21-rw_mutex /usr/bin/time ./ebizzy -m -P 57.85user 124.30system 1:42.99elapsed 176%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (0major+33555877minor)pagefaults 0swaps /usr/bin/time ./ebizzy -m -P 58.09user 124.11system 1:43.18elapsed 176%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (0major+33555876minor)pagefaults 0swaps /usr/bin/time ./ebizzy -m -P 57.36user 124.92system 1:43.52elapsed 176%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (0major+33555877minor)pagefaults 0swaps -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/