Messages in this thread | | | Date | Fri, 24 Feb 2006 09:40:28 -0500 | From | Benjamin LaHaise <> | Subject | Re: [PATCH] Avoid calling down_read and down_write during startup |
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On Thu, Feb 23, 2006 at 10:18:18PM -0500, Alan Stern wrote: > Ben, earlier you expressed concern about the extra overhead due to > cache-line contention (on SMP) in the down_read() call added to > blocking_notifier_call_chain. I don't remember which notifier chain in > particular you were worried about; something to do with networking. > > Does this still bother you? I can see a couple of ways around it.
Yes it's a problem. Any read lock is going to act as a memory barrier, and we need fewer of those in hot paths, not more to slow things down.
-ben -- "Ladies and gentlemen, I'm sorry to interrupt, but the police are here and they've asked us to stop the party." Don't Email: <dont@kvack.org>. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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