* Matthew Hawkins <[EMAIL PROTECTED]> wrote: > On 7/31/07, Ingo Molnar <[EMAIL PROTECTED]> wrote: > > * Kenneth Prugh <[EMAIL PROTECTED]> wrote: > > > CFS generally seemed a lot smoother as the load increased, while > > > SD broke down to a highly unstable fps count that fluctuated > > > massively around the third loop. Seems like I will stick to CFS > > > for gaming now. > > My experience was quite similar. I noticed after launching the second > loop that the FPS stuck down to 15 for about 20 seconds, then climbed > back up to 48. After that it went rapidly downhill. This is similar > to other benchmarks I've done of SD versus CFS in the past. At a > "normal" load they're fairly similar but SD breaks down under > pressure.
ok, thanks for testing it! > The only other thing of interest is that the -ck kernel had the WM > menus appear in about 3 seconds rather than 5-8 under the other two. under what load is that - 10 loops? There's no disk or network IO going on during a WM menu appearance, correct? This could be a time-slicing difference perhaps - if you have CONFIG_HZ=100 could you change it to 1000 (or if you have it at 1000, could you change it to 100) - does it show any sensitivity to that? the other difference could be SCHED_FEAT_START_DEBIT, does that WM menu latency go down if you clear it from sched_features, i.e. to subtract 16 from sched_features: echo 15 > /proc/sys/kernel/sched_features to restore the default, do: echo 31 > /proc/sys/kernel/sched_features (if you have CONFIG_SCHED_DEBUG=y). You might also want to try changing /proc/sys/kernel/sched_granularity_ns. Boundary conditions: make sure that if you change the sched_granularity value you also set /proc/sys/kernel/sched_runtime_limit_ns to 2*sched_granularity and set /proc/sys/kernel/sched_wakeup_granularity_ns to sched_granularity/2. Other interesting bits to experiment with in sched_features would be SCHED_FEAT_FAIR_SLEEPERS (mask '1' in the bitmask) and SCHED_FEAT_SKIP_INITIAL (mask '32' in the bitmask). Ingo - 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/