| Date | Wed, 1 Feb 2012 18:03:56 -0800 | From | Josh Triplett <> | Subject | Re: [PATCH RFC tip/core/rcu 14/41] rcu: Limit lazy-callback duration |
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On Wed, Feb 01, 2012 at 11:41:32AM -0800, Paul E. McKenney wrote: > Currently, a given CPU is permitted to remain in dyntick-idle mode > indefinitely if it has only lazy RCU callbacks queued. This is vulnerable > to corner cases in NUMA systems, so limit the time to six seconds by > default. (Currently controlled by a cpp macro.)
I wonder: should this scale with the number of callbacks, or do we not want to make estimates about memory usage based on that?
Interestingly, with kfree_rcu, we actually know at callback queuing time *exactly* how much memory we'll get back by calling the callback, and we could sum up those numbers.
- Josh Triplett
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