Messages in this thread | | | Date | Fri, 22 Aug 2008 20:33:46 +0200 | From | Andi Kleen <> | Subject | Re: [PATCH 2/2] smp_call_function: use rwlocks on queues rather than rcu |
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> 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?
Right now my impression is that it is not well understood why the kmalloc makes the IPI that much slower. In theory a kmalloc shouldn't be all that slow, it's essentially just a "disable interrupts; unlink object from cpu cache; enable interrupts" with some window dressing. kfree() is similar.
Does it bounce a cache line on freeing perhaps?
-Andi
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