From 1983a922a1bc843806b9a36cf3a370b242783140 Mon Sep 17 00:00:00 2001 From: Christian Ehrhardt Date: Mon, 30 Nov 2009 12:16:47 +0100 Subject: sched: Make tunable scaling style configurable As scaling now takes place on all kind of cpu add/remove events a user that configures values via proc should be able to configure if his set values are still rescaled or kept whatever happens. As the comments state that log2 was just a second guess that worked the interface is not just designed for on/off, but to choose a scaling type. Currently this allows none, log and linear, but more important it allwos us to keep the interface even if someone has an even better idea how to scale the values. Signed-off-by: Christian Ehrhardt Signed-off-by: Peter Zijlstra LKML-Reference: <1259579808-11357-3-git-send-email-ehrhardt@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'kernel/sched_fair.c') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 71b3458245e..455106d318a 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -21,6 +21,7 @@ */ #include +#include /* * Targeted preemption latency for CPU-bound tasks: @@ -37,6 +38,18 @@ unsigned int sysctl_sched_latency = 5000000ULL; unsigned int normalized_sysctl_sched_latency = 5000000ULL; +/* + * The initial- and re-scaling of tunables is configurable + * (default SCHED_TUNABLESCALING_LOG = *(1+ilog(ncpus)) + * + * Options are: + * SCHED_TUNABLESCALING_NONE - unscaled, always *1 + * SCHED_TUNABLESCALING_LOG - scaled logarithmical, *1+ilog(ncpus) + * SCHED_TUNABLESCALING_LINEAR - scaled linear, *ncpus + */ +enum sched_tunable_scaling sysctl_sched_tunable_scaling + = SCHED_TUNABLESCALING_LOG; + /* * Minimal preemption granularity for CPU-bound tasks: * (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds) -- cgit v1.2.3