Messages in this thread | | | Date | Fri, 22 Aug 2008 13:36:37 -0500 | From | Christoph Lameter <> | Subject | Re: [PATCH 2/2] smp_call_function: use rwlocks on queues rather than rcu |
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Paul E. McKenney wrote:
>>> So on your these large boxes, read-only cachelines are preferentially >>> ejected from the cache, so that one should write to per-CPU data >>> occasionally to keep it resident? Or is the issue the long RCU grace >>> periods which allow the structure being freed to age out of all relevant >>> caches? (My guess would be the second.) >> The issue are the RCU grace period that are generally long enough to make the >> cacheline fall out of all caches. > > Would it make sense to push the freed-by-RCU memory further up the > hierarchy, so that such memory is not mistaken for recently freed > hot-in-cache memory?
That would mean passing a gfp flag like __GFP_COLD on free from RCU? Or how would that work at the higher levels?
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