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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2007-08-25 18:41:53 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2007-08-25 18:41:53 +0200 |
| commit | 218050855ece4e923106ab614ac65afa0f618df3 (patch) | |
| tree | f7b1234ce9e8ad0bc5d5af949949251240ec6a2c /kernel/sysctl.c | |
| parent | 1fc84aaae3bae9646dd4c7798b8c0ff934338909 (diff) | |
| download | lwn-218050855ece4e923106ab614ac65afa0f618df3.tar.gz lwn-218050855ece4e923106ab614ac65afa0f618df3.zip | |
sched: adaptive scheduler granularity
Instead of specifying the preemption granularity, specify the wanted
latency. By fixing the granlarity to a constany the wakeup latency
it a function of the number of running tasks on the rq.
Invert this relation.
sysctl_sched_granularity becomes a minimum for the dynamic granularity
computed from the new sysctl_sched_latency.
Then use this latency to do more intelligent granularity decisions: if
there are fewer tasks running then we can schedule coarser. This helps
performance while still always keeping the latency target.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sysctl.c')
| -rw-r--r-- | kernel/sysctl.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c index ea90ef51085c..9e3d2960faf5 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -233,6 +233,17 @@ static ctl_table kern_table[] = { }, { .ctl_name = CTL_UNNUMBERED, + .procname = "sched_latency_ns", + .data = &sysctl_sched_latency, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &min_sched_granularity_ns, + .extra2 = &max_sched_granularity_ns, + }, + { + .ctl_name = CTL_UNNUMBERED, .procname = "sched_wakeup_granularity_ns", .data = &sysctl_sched_wakeup_granularity, .maxlen = sizeof(unsigned int), |