Messages in this thread | | | Date | Fri, 27 Jan 2006 15:28:57 -0800 | From | Andrew Morton <> | Subject | Re: [patch 2/2] fix file counting |
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"Paul E. McKenney" <paulmck@us.ibm.com> wrote: > > > > I am using a patch that seems sligthly better : It removes the filp_count_lock > > > as yours but introduces a percpu variable, and a lazy nr_files . (Its value > > > can be off with a delta of +/- 16*num_possible_cpus() > > > > Yes, I think that is better. > > I agree that Eric's approach likely improves performance on large systems > due to decreased cache thrashing. However, the real problem is getting > both good throughput and good latency in RCU callback processing, given > Lee Revell's latency testing results. Once we get that in hand, then > we should consider Eric's approach.
Dipankar's patch risks worsening large-SMP scalability, doesn't it? Putting an atomic op into the file_free path?
And afaict it fixes up the skew in the nr_files accounting but we're still exposed to the risk of large amounts of memory getting chewed up due to RCU latencies?
(And it forgot to initialise the atomic_t)
(And has a couple of suspicious-looking module exports. We don't support CONFIG_PROC_FS=m).
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