Re: [PATCH v7 05/19] iov_iter: Introduce fault_in_iov_iter_writeable

[Tony Luck]

On Sat, Aug 28, 2021 at 3:12 PM Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:
> BTW, is #MC triggered on stored to a poisoned cacheline?  Existence of CLZERO
> would seem to argue against that...

No #MC on stores. Just on loads. Note that you can't clear poison
state with a series of small writes to the cache line. But a single
64-byte store might do it (architects didn't want to guarantee that
it would work when I asked about avx512 stores to clear poison
many years ago).

-Tony