Re: [PATCH 0/3] v2 Make hierarchical RCU less IPI-happy and addmore tracing

[Ingo Molnar]

* Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> wrote:

> This three-patch set fixes a hierarchical-RCU performance bug 
> located by Anton Blanchard.  This bug affects certain high-end 
> floating-point computation-heavy workloads with closely spaced 
> barrier-synchronized iterations, where an interruption of any one 
> CPU's processing during a given iteration slows the system as a 
> whole.  This bug manifests itself as excessive resched IPIs, and 
> is strictly a performance regression. It does not affect 
> correctness.
> 
> The first patch provides the fix for the problem, the second patch 
> adds the tracing, and the third patch adds the documentation for 
> the tracing.
> 
> Located-by: Anton Blanchard <anton@xxxxxxxxxxx>
> Tested-by: Anton Blanchard <anton@xxxxxxxxxxx>
> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>

i've applied the first patch to tip:core/urgent (for .30) and the 
second and third one to tip:core/rcu (for .31).

Thanks Paul,

	Ingo
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