Messages in this thread | | | Subject | Re: [PATCH tip/core/rcu 13/23] rcu: Control grace-period duration from sysfs | From | Peter Zijlstra <> | Date | Thu, 06 Sep 2012 20:28:21 +0200 |
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On Thu, 2012-09-06 at 10:53 -0700, Paul E. McKenney wrote:
> > - how do I know if my workload wants a longer or shorter forced qs > > period? > > Almost everyone can do just fine with the defaults. If you have more > than about 1,000 CPUs, you might need a longer period.
Because the cost of starting a grace period is on the same order (or larger) in cost as this period?
> Some embedded > systems might need a shorter period -- the only specific example I know > of is network diagnostic equipment running wireshark, which starts up > slowly due to grace-period length.
But but but 3 jiffies.. however is that too long?
> > Also, whatever made you want to provide this 'feature' in the first > > place? > > Complaints from the two groups called out above.
Does this really warrant a boot time knob for which even you cannot quite explain what values to use when?
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