Re: Should we cacheline align PGXACT?

Alexander Korotkov <a(dot)korotkov(at)postgrespro(dot)ru> writes:
> On Fri, Aug 19, 2016 at 4:46 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> That's one mighty ugly patch. Can't you do it without needing to
>> introduce the additional layer of struct nesting?

> That's worrying me too.
> We could use anonymous struct, but it seems to be prohibited in C89 which
> we stick to.
> Another idea, which comes to my mind, is to manually calculate size of
> padding and insert it directly to PGXACT struct. But that seems rather
> ugly too. However, it would be ugly definition not ugly usage...
> Do you have better ideas?

No, that was the best one that had occurred to me, too. You could
probably introduce a StaticAssert that sizeof(PGXACT) is a power of 2
as a means of checking that the manual padding calculation hadn't
gotten broken.

regards, tom lane