Messages in this thread | | | Date | Wed, 26 Jun 2019 23:16:10 +0200 | From | Peter Zijlstra <> | Subject | Re: [RFC PATCH v2 1/2] printk-rb: add a new printk ringbuffer implementation |
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On Mon, Jun 24, 2019 at 10:33:15AM +0200, John Ogness wrote: > Here are the writer-relevant memory barriers and their associated > variables: > > MB1: data_list.oldest > MB2: data_list.newest > MB3: data_block.id > MB4: descr.data_next > MB5: descr_list.newest > MB6: descr.next
I think this is the fundamental divergence in parlance.
You seem to associate a barrier with a (single) variable, where normally a barrier is between two (or more) variables.
As you wrote in that other email (I'm stlil going through all that); your MB5 isn't desc_list.newest, but rather between desc_list.newest and descr.next.
Remember, the topic is called 'memory ordering', and you cannot order singles.
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