Re: [PATCH next v2 2/3] printk: change @clear_seq to atomic64_t

[Peter Zijlstra]

On Mon, Dec 07, 2020 at 11:09:39AM +0106, John Ogness wrote:
> That will not work. We are talking about a situation where the writer is
> preempted. So seq will never equal seq_copy in that situation. I expect
> that the seqcount_latch is necessary.

Interrupted rather, I would think, specifically NMIs? Then yes, latch
should work. Gets you either the old or new, but never something in
between.