[PATCH 11/32] nohz/cpuset: Don't turn off the tick if rcu needs it
cl at linux.com
Wed Mar 28 00:42:42 UTC 2012
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
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