Hi, I've been working on a concurrent threading framework. It is a userlevel library, which consists of a thread pool and it heavily uses mutex locking and condition variable signaling.
I'm testing this on hyper-threaded Intel Atom D510 CPU, which shows up as 4 CPUs. The test runs a tight loop, in which it assigns 4 parallel tasks to threads, and waits for those tasks to complete. For some reason I'm getting really bad performance results with NetBSD (5.1-STABLE amd64). I suspect something is not quite right in pthreads library, or at the kernel level. Below are test results. Any ideas why concurrency on NetBSD is so bad compared to Solaris? It seems as if on NetBSD threads are stuck on a wait list for much longer. Solaris running times and vmstat output for CPU user, system and idle: real 28.7 user 1:38.4 sys 4.0 us sy id -------- 1 0 99 42 3 55 86 6 8 86 6 8 86 6 8 86 6 8 86 6 8 87 6 7 86 6 8 86 6 8 87 6 7 86 6 8 87 6 7 87 6 8 86 6 8 87 6 8 86 6 7 86 6 8 86 6 8 86 6 8 86 6 8 86 6 8 86 6 8 86 6 8 87 6 7 87 6 7 86 6 8 86 6 8 86 6 8 NetBSD running times and vmstat output for CPU user, system and idle: 57.61 real 142.19 user 1.86 sys us sy id -------- 1 0 99 2 0 98 0 0 100 30 0 69 95 1 4 61 0 38 49 0 50 66 1 33 92 1 7 95 1 4 67 0 33 85 0 14 54 1 45 70 1 29 50 1 49 50 1 49 53 0 46 50 0 50 47 1 52 45 1 54 37 2 61 34 1 65 55 1 44 74 1 26 70 2 28 80 1 19 95 1 5 79 1 21 52 0 48 50 0 50 47 1 52 50 0 50 47 0 52 51 1 48 53 0 47 49 1 50 48 0 51 47 0 53 52 0 48 50 0 50 49 1 50 53 1 46 52 0 47 53 1 46 52 1 48 49 1 50 43 0 56 33 1 66 34 0 66 32 1 67 54 1 45 95 0 4 92 1 7 95 1 4 87 1 12 82 1 17 56 1 43 93 2 5 94 2 4 87 1 12 60 1 39
