Messages in this thread | | | Date | Sun, 16 Oct 2005 05:48:55 +1000 | Subject | Re: Possible memory ordering bug in page reclaim? | From | Herbert Xu <> |
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On Sat, Oct 15, 2005 at 06:00:18PM +0000, Andrea Arcangeli wrote: > > Note that the barrier in atomic_add_negative is useless here because it > happens way too late, _after_ the count is decremented (not _before_) > so the decreased count could be already visible to the other cpu.
Could you please point me to an architecture that does this?
This assumption is in fact made in a number of places in the kernel where constructs such as atomic_add_negative or atomic_dec_and_test are used and assumed to imply a memory barrier.
Thanks, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au> 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 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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