Messages in this thread | | | Date | Tue, 27 Mar 2012 19:42:42 -0500 (CDT) | From | Christoph Lameter <> | Subject | Re: [PATCH 11/32] nohz/cpuset: Don't turn off the tick if rcu needs it |
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On Tue, 27 Mar 2012, Steven Rostedt wrote:
> On Tue, 2012-03-27 at 11:13 -0500, Christoph Lameter wrote: > > > Please do not use "realtime" since I am not sure what you mean by that. > > Its for a low latency applications that cannot use "realtime" because that > > implies high latencies. > > This statement totally confuses me, as the whole point of the -rt > (realtime) patch, is for lower latencies. Where do you get "realtime" > implies high latencies from?
Obviously compiling a kernel with preemptiong introduces additional overhead to guarantee more deterministic behavior. Additional overhead increases latencies generated by the OS in general. Compile a kernel without preemption and it will run faster and thus have lower latencies.
Realtime avoids high latency spikes but in general increases average OS latencies.
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