On Fri, Aug 17, 2007 at 01:43:27PM +1000, Paul Mackerras wrote: > > The cost of doing so seems to me to be well down in the noise - 44 > bytes of extra kernel text on a ppc64 G5 config, and I don't believe > the extra few cycles for the occasional extra load would be measurable > (they should all hit in the L1 dcache). I don't mind if x86[-64] have > atomic_read/set be nonvolatile and find all the missing barriers, but > for now on powerpc, I think that not having to find those missing > barriers is worth the 0.00076% increase in kernel text size. BTW, the sort of missing barriers that triggered this thread aren't that subtle. It'll result in a simple lock-up if the loop condition holds upon entry. At which point it's fairly straightforward to find the culprit. Cheers, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} <[email protected]> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] 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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