Messages in this thread | | | Date | Thu, 7 May 2009 13:51:58 -0400 (EDT) | From | Christoph Lameter <> | Subject | Re: [PATCH] x86: Reduce the default HZ value |
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On Thu, 7 May 2009, Paul E. McKenney wrote:
> On Thu, May 07, 2009 at 01:20:29PM -0400, Christoph Lameter wrote: > > On Thu, 7 May 2009, Peter Zijlstra wrote: > > > > > Another user is RCU, the grace period is tick driven, growing these > > > ticks by a factor 50 or so might require some tinkering with forced > > > grace periods when we notice our batch queues getting too long. > > > > One could also schedule RCU via hrtimers with a large fuzz period? > > You could, but then you would still have a periodic interrupt introducing > jitter into your HPC workload. The approach I suggested allows RCU to be > happy with no periodic interrupts on any CPU that has only one runnable > task that is a CPU-bound user-level task (in addition to the idle task, > of course).
Sounds good.
An HPC workload typically has minimal kernel interaction. RCU would only need to run once and then the system would be quiet.
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