The staircase deadline cpu scheduler continues to be the reference with respect to interactive fairness for many workloads especially with 3d gaming. This version is only trivially different from the version included in the -ck patchset which has been very stable. The version number has been incremented to version 1.00 purely to reflect that stability. Those on -ck are already running the equivalent of this version.
http://www.kernel.org/pub/linux/kernel/people/ck/patches/staircase-deadline/2.6.22-rc2/2.6.22-rc2-sd-1.00.patch In comparison with the standalone version 0.48 of sd the changes are as follows: Default rr_interval was increased to 10ms on uniprocessor (it is scaled up on SMP) for throughput reasons. Note that -ck has 6ms and -cks has 10ms as defaults (on UP, double that for 2 cpus). This can be altered (as always) by modifying the value in /proc/sys/kernel/rr_interval. The PRIO value exported to userspace as seen by 'top', 'ps' etc will now reflect the relative priority of tasks on the expired array by their value being greater than 39. The interactive tunable patch was rolled into this patch and is enabled by default. Note the effect of this tunable is subtle except on 3d games. This can be altered by modifying /proc/sys/kernel/interactive. A summary of the interactive sysctl from Documentation/sysctl/kernel is: The staircase-deadline cpu scheduler can be set in either purely forward-looking mode for absolutely rigid fairness and cpu distribution according to nice level, or it can allow a small per-process history to smooth out cpu usage perturbations common in interactive tasks by enabling this sysctl. While small fairness issues can arise with this enabled, overall fairness is usually still strongly maintained and starvation is never possible. Enabling this can significantly smooth out 3d graphics and games. -- -ck - 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/
