I decided to test RIFS v2, v3-RC1, v3-RC2, and CFS 3.4-rt.
All three of RIFS get high latency on a standard cyclictest run (50us instead of the average 1 on CFS or 0 on BFS or CFS+RT-preempt).
Using 'latt stress -c 64', v3-RC2 hangs the machine completely (just like BFS), v3-RC1 nearly does so and if you're lucky you can kill it.
Wakeup latencies (according to latt) on RC2 are in the 500us range average.
v2 works as advertised, and up to 128 threads will keep CPU bound tasks going fine, and latt reports wakeup latencies in the 3us range for 32 threads, but 1028 us for 64. Notably, I/O seems to get starved, however. They are entirely inconsistent, however.
As far as miscellaneous problems... On v2, results with latt are inconsistent in returning. Sometimes it'll return nothing at all. v3-RC2 occasionally won't boot because the storage subsystem hasn't initialized by the time it tries to boot (haven't seen that before, and only sometimes on v3-RC2).
However, kernel compile times on v2 (make -j4) seem to take much, much longer than with anything else. On the order of 3 times longer.
All of this is in X11 and with r600g, with a Touhou 3D game (via wine) running concurrently with the tests to ensure things are really interactive and that audio works correctly.
3.4-rt (CFS) seems to work correctly anywhere from -c1 to -c256, with latt-reported wakeups in the 3 average, 10 max for 64 stress processes. 66 average, 818 max for 256 stress processes. CFS-rt doesn't starve I/O.
All three of RIFS get high latency on a standard cyclictest run (50us instead of the average 1 on CFS or 0 on BFS or CFS+RT-preempt).
Using 'latt stress -c 64', v3-RC2 hangs the machine completely (just like BFS), v3-RC1 nearly does so and if you're lucky you can kill it.
Wakeup latencies (according to latt) on RC2 are in the 500us range average.
v2 works as advertised, and up to 128 threads will keep CPU bound tasks going fine, and latt reports wakeup latencies in the 3us range for 32 threads, but 1028 us for 64. Notably, I/O seems to get starved, however. They are entirely inconsistent, however.
As far as miscellaneous problems... On v2, results with latt are inconsistent in returning. Sometimes it'll return nothing at all. v3-RC2 occasionally won't boot because the storage subsystem hasn't initialized by the time it tries to boot (haven't seen that before, and only sometimes on v3-RC2).
However, kernel compile times on v2 (make -j4) seem to take much, much longer than with anything else. On the order of 3 times longer.
All of this is in X11 and with r600g, with a Touhou 3D game (via wine) running concurrently with the tests to ensure things are really interactive and that audio works correctly.
3.4-rt (CFS) seems to work correctly anywhere from -c1 to -c256, with latt-reported wakeups in the 3 average, 10 max for 64 stress processes. 66 average, 818 max for 256 stress processes. CFS-rt doesn't starve I/O.
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