> On Jun 26, 2020, at 4:05 AM, Joerg Roedel <[email protected]> wrote:
>
> a previous discussion pointed out that using atomic64_t for that
> purpose is a bit of overkill. This patch-set replaces it with unsigned
> long and introduces some helpers first to make the change more easy.
BTW, from the previous discussion, Linus mentioned,
“
The thing is, the 64-bit atomic reads/writes are very expensive on
32-bit x86. If it was just a native pointer, it would be much cheaper
than an "atomic64_t".
“
However, here we have AMD_IOMMU depend on x86_64, so I am wondering if it makes
any sense to run this code on 32-bit x86 at all?
