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    SubjectRe: [PATCH] x86, mce: Fix rcu splat in drain_mce_log_buffer()
    On Fri, Jan 13, 2012 at 01:44:35PM -0800, Paul E. McKenney wrote:
    > Looks good to me, but I do need to defer to people who know this code
    > better than do I. The key thing that (from what I can see) makes
    > rcu_dereference() unnecessary is that the smp_rmb() used in conjunction
    > with polling the .finished field takes care of ordering.

    Right, this was me trying hard not to screw up touching mcelog.next,
    thus trying to use the rcu_dereference_index_check() primitive without
    thinking it through too much. But you're right, I'm polling the
    ->finished field 4 times (totally arbitrary, btw) which should suffice
    while the mce_log() routine above writes those entries.

    Although, the question still remains, since mce_log() accesses
    mcelog.next through the rcu_dereference_index_check() primitive,
    shouldn't I do it the same way?

    Thanks.

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    Regards/Gruss,
    Boris.

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